rere

ede
stat,
ata

>:
.
bed

Ses

tate
ty
Sa$s >

Ad

;
>5>9)

Mata
aoe
Saisaatiss

,
ates
eS a94%49

a

i449

te

Py.

iG

ate

>

>
>
>

>
,

>
4)

>
5?

etter tetcndes .
asta tetessssets
at atet
VERTIS

ah geet at ase sd
preretoeat
tetetatatete

tree
roe
pepe bese

>
aa atts
afeleles

PLP. PoP rer
etatet tice
>
batete o4

ie
¥
ales etetelacs

e

tpt

tetate fata
preset etatate
Eat etetssa’ ete

+t

, ,
Sata sece
bby ;
ii4seasae

>

sai

>
sae ,
Perle ete
Hetatats
Metetat.

ret ats
telaseees
att ate
Hasestets

(343449

194549494)

Rat >
434349
>?

> is
ise
Ia etessscsesdesesess

a
>
>

Isha tatasesa te
tee brer> Hi
>? prerethe se

resist at atataeae
eecdatata seit

iad

> re
4 ,

ise4
seseee

i
aes
iat etais

ppataaanaa tect
se

ts ateesss TYLPS UDP pear yet ploretesrarase?
+ poetics ca tate Pebpls?: Poretes .

SAEs hese rcead cots aaa seat toseccce$

pester SEeheceatbest tee i

Rotate tes aislelstitice

« >
hat eh eh ee
besasets PLP
ase

tp }
, is 3

tat eet atee
att
eit

CUTE

¥

Se

Soe

ey

*

SS
aa
Ss

ee

oo
a

rote
Sa
vee
cetae

i

> Ply
ptt tate
eyeiate HS felete

ait H PT
anaes

ret
Pleo

i

Rs
ARES
SOIT
eee
yy re
et
eet ewe eye Aaa as

Se

ss
rele)
ree?

>

oS
wee wees

ses

VV WEVeyyeweurnew

- ao,
sea

ee ee
oa

vey

wwveeue
VV EEE)
AA,
ee

PO
ars
©.
a

eee
ww

oS
eS
Mee

ees
Maes
eee eee a ee
-.
ere

wewer yew e

wee
a

SO
aaa

os
se Xe aah
ae
eee
PRI
Oe
aa
Senna

es

cae
vets .

Case
vow’
aA,
oe
Seer
$4554
eevee.

CO
=

CONAN

Seer
vey
eer eee

ow
ete.

~

~~ ew
ae
ee err ere e

ee
‘e

—e
“ey

TY
weeee

e
oo

Se

“+ wee
ete
Ss

sae
ot -
A
oye
Aa,

eres
vee

ae
=
es

~
~

Y

Tey

wereree

Tererrverery
©

~

‘e
ee
Soyere oe
creeper
AA ae
7

ee
Sore orete

Vere
e's
&
S
eee owe

eis

rete

“e

vyry
oS

eee

eww eu e

ay AP SN Pred
seeteasiget
Preps rites bebe
iehesssttaoetaedseiets

7»

in

ee ane ey

ve

ES
Se ©
Setete etek
a A.
eee
ee

ye
eey
as aa

one

<

—_ “~
SS
LEE

Ses

pot etet et
fads

SASS

TeTtt
ak

See Te

a

ee

eves
eve

eee

=a a

Fete ewes

<

Se

>>

THE

NAW ES TORY

OF THE

MARKETABLE MARINE FISHES

OF THE

BRITISH ISLANDS

(she,

NATURAL HISTORY

OF THE

MARKETABLE MARINE FISHES

OF THE

BRITISH ISLANDS

\

PREPARED BY ORDER OF THE COUNCIL OF THE MARINE BIOLOGICAL
ASSOCIATION ESPECIALLY FOR THE USE OF THOSE INTERESTED
IN THE SEA-FISHING [INDUSTRIES

p° BY
eal SC UNNING ELAM MeEA> Oxon:
iar
FORMERLY FELLOW OF UNIVERSITY COLLEGE, OXFORD

NATURALIST ON THE STAFF OF THE MARINE BIOLOGICAL ASSOCIATION ; CORRESPONDING
MEMBER OF THE DEUTSCHER SEEFISCHEREIVEREIN

Wit A] PREFACE, BY
eee we NK Si Re MEARS PRS: i

LINACRE PROFESSOR OF COMPARATIVE ANATOMY IN THE UNIVERSITY OF OXFORD,
PRESIDENT OF THE MARINE BIOLOGICAL ASSOCIATION

London
MeN GEM lee AN cAGN 1): COM sera)

INJIWi VOR Ete, ViAC MilE EAN CO:

The

> 7
VL ESEITER

RicHAarRD CLAy AND Sons, LIMITED,

LONDON AND BUNGAY

le] ereatel ey

THE work which, as President of the Marine Biological
Association, I have the pleasure of introducing to the public
with a few lines of preface, has been prepared at the request of
the Council of the Association by Mr. J. T. Cunningham. The
author has for several years occupied the position of naturalist
at the Plymouth laboratory, being especially charged by the
Council with the investigation of the structure, habits, and
breeding of marine food-fishes. He had previously given a large
amount of study to this subject whilst in charge of the marine
laboratory at Granton near Edinburgh. Since many of Mr.

ce

Cunningham’s important observations on the ‘‘ growth from the
egg ” of marine fishes have been published in the strictly scientific
journals and transactions of societies, it seemed to be desirable
that the results of the recent study of the reproduction of the
fishes which form the material of our sea-fisheries, should be
brought together in a convenient and popular form, The marked
increase of attention to the natural history of these fishes which
is traceable to the great Fisheries Exhibition held in London in
1883, has led to a large increase of knowledge. On various
parts of our coasts, naturalists have been busy in the endeavour
to arrive at an accurate estimate of the causes which determine
the movements and the variations in abundance of the animals
which produce the “harvest of the sea,” -An immense amount
of work remains to be done before we shall be in a position to
control the operations of fishermen or to assist them by advice

v1 PREFACE

or forecasts in a satisfactory manner. At the same time a good
deal has been done, and the work is one in which amateurs all
round our shores can assist. Mr. Cunningham’s book will, it is
hoped, serve as a help not only to trained investigators but to
those who are able to give some portion of their leisure to this
important subject. It is hoped also that it may help those who
are responsible for giving or withholding public funds to the
thorough investigation of marine fisheries, in forming a judgment
as to the nature of the problems which have to be solved. The
national importance of the sea-fisheries industry is recognized
by the legislature. But the right way of developing and directing
that industry, and indeed whether it is possible to do anything
to improve that industry, are questions which seem still to be
matters of doubt to all but the professed students of marine life
and its conditions. This book, together with the several volumes
of the journal of the Marine Biological Association and the
finely illustrated monograph by Mr. Cunningham on the common
sole, may be taken as setting forth the results of the work done
by the Marine Biological Association in the direction of con-
tributing to a better knowledge of sea-fishes and _sea-fisheries.
That work has been done to a large extent by the aid of grants
from Her Majesty’s Treasury, with which the Association has
been entrusted by the Government. The line of work pursued
has been necessarily limited by the funds at the disposal of the
Council of the Association. The results obtained are undoubt-
edly valuable; at the same time I cannot let this opportunity
pass of stating that a larger and much more costly series of
investigations is necessary, and that nothing short of a physical
and biological survey of the North Sea and of the area within
the hundred-fathom line on our southern and western coasts can
yield the information as to the movements of marine food-fishes
and the distribution of fishing-grounds which is needful if we are
to deal intelligently with our sea-fisheries. This and the collec-
tion (even though costly) of statistical information as to the
capture of fish on specified fishing-grounds, which at the present

PREFACE vil

moment is entirely neglected though practicable, are the two
requirements of those who desire to improve, and preserve by
intelligent action, our fishing industry. I believe that Mr.
Cunningham’s book will place the reader in a position to
appreciate the importance of these requirements.

The purpose of the Association under the auspices of which
Mr. Cunningham has worked, was stated, on its foundation, in
the words of Professor Huxley, its first President, to be that of
“establishing and maintaining laboratories on the coast of the
United Kingdom, where accurate researches may be carried on
leading to the improvement of zoological and botanical science,
and to an increase of our knowledge as regards the food, life-
conditions, and habits of British food-fishes and molluscs.” The
Association was founded in 1884 and the Plymouth laboratory
was opened in 1888, having cost in building and fittings about
412,000. The studies of the naturalists, who are officers of the
Association, have not been confined to the neighbourhood of
Plymouth, but have included some investigation of the North
Sea fisheries, in the course of which the marine laboratory at
Cleethorpes was lent to the Association by the Society to which
it belongs. Those who read Mr. Cunningham’s account of our
marine food-fishes and feel an interest in the subject of which
he treats, and in the enterprise of the Marine Biological Associa-
tion, will be able to obtain all information as to the Association,
its laboratory, its publications, and the terms of membership by
applying to the Director of the Marine Biological Laboratory,
Citadel Hill, Plymouth. It would not perhaps be in good taste
to discourse at greater length in this preface concerning the
Association and its laboratory. I will, however, venture so far
as to state that in addition to promoting and publishing works
directly relating to sea fisheries, the Association has through its
laboratory and fishing boats at Plymouth furnished a large
number of naturalists who have occupied tables there, with the
means of prosecuting minute researches of great scientific value
on the marine fauna and flora. It is also the means of providing

Viil PREFACE

University and College teachers with large supplies of marine
organisms for teaching purposes and special investigations. Its
aims are national in their importance and not merely local ; it
requires and invites the co-operation of all those who are
interested in the study of marine life, or in the perilous labours
of the sea fisherman.

Before concluding this preface I must express the thanks
of the Council of the Marine Biological Association to the
Council of the Royal College of Surgeons of England, and the
Hunterian Curator, Professor Stewart, F.R.S., for kindly allow-
ing Mr. Cunningham to make use of a room in their Museum
during the past year whilst engaged in preparing this book
for the press, and in pursuing his researches on the structure of
the ovary of marine food-fishes.

E. RAY LANKESTER.

October, 18096.

CONTENTS

PART I.—GENERAL

CHAPTER I

PAGE

HISTORY OF MODERN INVESTIGATIONS OF THE SUBJECT ; : 3
SUAVE IM AIS IL

THE CHARACTERISTICS OF VALUABLE MARINE FISHES AND THE REGIONS

IN WHICH THEY LIVE , : : : : ; 2 ‘ 32
CHAR SVE TRS 1

THE GENERATION OF FISHES AND THEIR FECUNDITY . : ; . 62
CEVA AEE RS Vi

THE EGGS AND LARVA AND THEIR DEVELOPMENT ‘ : ‘ 85
CHAPTER V

GROWTH, MIGRATIONS, FOOD AND HABITS : : : : 5 ue

CIA PTR Vil

PRACTICAL METHODS OF INCREASING THE SUPPLY OF FISH . . 135

x CONTENTS

PART IlL—HISTORY OF PARTICULAR FISHES

PAGE

THE HERRING FAMILY é : ‘ : P : 147
THE HERRING. ; : : ; 4 j 2 156
THE SPRAT : j 2 : : : ; : 5 ati(oye
THE PILCHARD OR SARDINE . : 4 : : : 6s
THE SHADS ; : : - 378
THE ANCHOVY . : 5 : é F PE LO?
THE SALMON FAMILY : : E ’ ; , ; Be itsty/
THE SMELT ; : ! : ‘ ; ; 5 5 aiesys)
THE EEL FAMILY ‘ : : ; ; , ; : 5 OR
THE EEL . ; 5 : : 5 ; : . 196
THE CONGER ‘ : : E ; : 3 . = 199
THE GARFISH OR GUARD-FISH FAMILY. ; : é : . 206
THE FLAT-FISH FAMILY ; : : ; ‘ é 5 208
THE PLAICE , ; 5 : 5 : : ‘ ele
THE COMMON DAB F : : : : ; ‘ af io DDE
THE FLOUNDER . j : : ‘ «a 22y
THE WITCH : : é : ; é : 3 ete)
THE LEMON DAB, OR LEMON SOLE. : : 5 é = 236
THE HALIBUT . : : ; : ; : : . S242
THE LONG ROUGH DAB. : : , 244
THE SOLE , < : : : : ; : ; 3) 5240
THE SAND SOLE, OR FRENCH SOLE . : : i 3 ee Sy)
THE SOLENETTE, OR LITTLE SOLE . : . ; : 5” 2S
THE THICKBACK . s ; : : : ; : = 9250)
THE TURBOT P , ; ; : ; : A260)
THE BRILL . 5 : ; : ‘ ‘ 5 4 ey
THE MEGRIM : j s ‘ ‘ ; d ; erin
THE SCALDFISH, OR SCALDBACK : ; z : ; e274
THE TOP-KNOTS . é 3 : : ‘ : 5 e270
THE COD FAMILY E : > 5 F : : , e790

THE COD

CONTENTS <i

PAGE

THE COD FAMILY—(cozz/2z7d )
THE HADDOCK . F 3 : ‘ : 3 : 1 2077
THE WHITING. : : : : : : : = 200
THE COAL-FISH . j : : : 2 : : 203
THE POLLACK . : 2 : : : : : 5 8204
THE LING . ; : E . é : , 5 Bos
THE HAKE : : : , ; ; ; ; 5 Boys)
THE ROCKLINGS . : : : 5 ; : : 300
THE TUSK, OR TORSK . : ; 2 : : : 02
THE SAND-EELS . : : ; J : : : ses
THE RED MULLET FAMILY F 306
THE SEA BREAMS ' : ; ; : : : 2309
THE MACKEREL OR TUNNY FAMILY : : ; : 2 SLI
THE MACKEREL . : : ; : : : : ee
THE FAMILY OF THE SCADS, OR HORSE-MACKERELS : : ~ | Bins
THE JOHN DORY FAMILY 320
THE BOAR-FISH, OR CUCKOO . ; : : : : 320
THE JOHN DorRY . | 321
THE GURNARD FAMILY : : : ; ; ; : 5 en
THE BULLHEADS . : : : : : ‘ 2 320
THE GURNARDS . : ‘ ; : : ; : es28
GREY MULLETS s : ‘ : : : : o Seyl
THE THICK-LIPPED GREY MULLET. ; F : é x SBE
THE ANGLER FAMILY ~~ . : ’ : 2 : » ) 336
THE ANGLER OR FROG-FISH . ; : : , : pace
THE BLENNIES . : ; : 3 2 ; é 4 43
THE CAT-FISH, OR SEA-CAT : 345
THE SUCKER FAMILY . ' ; : F : ; : - 349
THE LUMP-SUCKER ; : f : P ; : - 349
THE DIMINUTIVE SUCKERS. ; : : : : She
APPENDIX I. — . ‘ 355
INDIAINIDIBS IGE ee 363

INDEX : : : . 3 : : : : 369

FIG.

Oe ies Oe ane eee

—
io)

Le

LIST OF ILLUSTRATIONS

PAGE
The Smaller Spotted Dog-fish , - é . : : ‘ 34
The Lancelet, or Amphioxus, an Enlarged Figure from a Living Specimen
obtained at Plymouth . 5 ; : : : : 36
The Bass, as example of the bony fishes t : : P ; 38
The Spiny Dog-fish, or Spur-dog : : P : : : 4I
The Common Skate, lower or ventral surface : : ; : 44
The Thornback, dorsal surface . : : : : é : 45
The Herring : ; 5 : : E : : : 46
The Smelt —_.. : : : : : - : : 46
The Conger 5 F : 3 : : ; ; ; 47
The Common Eel : : ; : : ‘ : 5 47
The Gar-pike, Guard-fish, or Long-nose : : L : E 48
The Saury-pike, or Skipper — . : ; Dy : : : 48
The Cod . : é : ‘ ; : : : F 49
The Plaice : ; : : : 2 : : : 50
The Common Sea Bream : : : : : ; : 51
The Striped Red Mullet - , 4 : : ‘ : 52
The Common Scad, or Horse Mackerel : : : : : 52
The John Dory . 2 : : : : : : : 53
The Mackerel . : : : ‘ : : : : 54
The Angler, Fishing Frog, or Monk-fish ‘ . 4 : ; 54
The Common or Grey Gurnard 2 : : ; : E 55
The Lump-sucker : : : ; : - : : 55
The Dragonet, male - : : : : : ; 56
The Cat-fish : : : : : ; ; : 56

LIST OF ILLUSTRATIONS

25. The Thick-lipped Grey Mullet .

26. The Fifteen-spined or Sea Stickleback
27. The Common or Ballan Wrasse

28. The Common Pipe-fish .

29. Diagram of a dissection of a female of the smaller spotted Dog-fish to
show the ovary and oviducts (after Milnes Marshall)

30. Diagram of a Herring with its body cavity laid open at the lower edge, to
show the roes and intestines, &c.

31. Diagram of the interior structure of the soft roe or testis in the Herring.
32. Similar diagram of the hard roe or ovary of the same fish .
33. .Sperms of various fishes, highly magnified

34. The abdomen of the female Sole, laid open with the organs in their
natural position

35. The same after removal of the liver and gut, the roe seen in its whole
length . j , : : §

36. The abdomen of the male Sole laid open with the organs in their natural
position .

37. The same after removal of the liver and gut .

38. Exyg of the larger Spotted Dog-fish, or Nurse-hound (after Day)
39. Living Egg of the Herring, magnified

40. Egg of the Sea-snail (Zzfar7s) as seen when alive and magnified
4t. Egg of the Double-spotted Sucker (Lefadogaster)

42 Egg of a species of Goby, from lower side of stone on shore at Falmouth
43. Butter Fish with its mass of spawn (after Holt)

44. Egg of the Smelt, with its suspending membrane

45-48. Diagrams of the chief types of floating marine fish-eggs

49. <A single globule of Noctiluca

50-54. The development of a buoyant marine fish-egg

55. Newly-hatched young (larva) of the Common Black Goby .

56-58. Three stages in the development of the Cod, showing the transforma-
tion of the larva into the perfect form

59-62. Four stages in the transformation of the Flounder

63. The Common Hermit Crab, lying beside the whelk-shell which it inhabits
64. A Swimming Crab

65. Ampelisca, a common marine Amphipod

66-70. Molluscs which commonly serve as food for fishes

XI

PAGE

57
57

oy
58

63

65
66
66
73

75

75

XIV LIST OF ILLUSTRATIONS

F1G PAGE
71-73. Marine Worms which commonly serve as food for fishes F 2. eked
74. A Sand-star (Ophiura albida) . , : : ; , y) tl25
75. <A Brittle-star (Amphiura filiformis) . : : ts
76-81. Some examples of minute pelagic animals : : : oy Lei
82. <A luminous Shrimp (Wyctiphanes) (after G. O. Sars) t 7 = 129
83. The gill-bars and gill-rakers of the Herring, the gill filaments which are

attached to the outer sides of the gill-bars having been removed 1 LST

84. Egg of the Herring, the embryo about half developed, alive, and magnified 158

85. Larva of the Herring, newly hatched, alive and magnified ‘ ~ | $150
86. Egg of the Sprat, alive, magnified 166
87. Newly-hatched larva of the Sprat, alive, magnified ‘ E 166
88. Egg of the Pilchard, alive, and magnified. : 5 : ely
89. Newly-hatched larva of the Pilchard, alive, and magnified : we LS
go. Larva of the Pilchard, nine days old, alive, magnified . : Be 7h 3
gt. Larva of Pilchard at commencement of transformation, after preser-
vation in spirit , : - : : : : Lye:
92. Older stage of Pilchard larva, after preservation. é : eel
93. Larva of the Twait Shad, nearly 2 inch long (after Ehrenbaum) . 5 Eso
94. Larva of the Twait Shad, 4 inch long (after Ehrenbaum) . ; 5 -atisio)
95. Egg of the Anchovy, alive, and magnified (after Wenckebach) . Sess
96. Larva of the Anchovy, newly hatched, alive, and magnified (after
Wenckebach) : : F f : ; : 5 AuSyl
97. Larva of the Smelt, $ inch long, 6 days old (after Ehrenbaum) . 2) ago
98. Larva of Smelt, = inch long (after Ehrenbaum) : : : 5 LOO
99. Leptocephalus Morrisiz, the larva of the Conger (after Couch) . ~ 20
100-105. ‘The two sides of the head in three different stages in a left-sided
young flat-fish in which the right eye passes through the head region
to reach the left side (Rhombordichthys) (after Steenstrup) : Veoke eee
106, Larva of Plaice five days old, alive, and magnified : : ape SLT,
107. Larva of Plaice in process of transformation, = inch long, alive, and
magnified ; : : : : P c : 5 tte)
108. Larva of the Witch or Pole Dab, two days old, alive, and magnified . 235
tog. Young Witch, a little over 1% inch long, from a preserved specimen
(after Holt) . ; F : 2 : : ; ee eee

110. Larva of Lemon Dab, or so-called Lemon Sole, two days old, alive, and
magnified — - - : : : : = 239

120.

List? OF ILLUSTRATIONS XV

Young Lemon Dab in last stage of transformation, slightly more than ej

I inch long. From a preserved specimen (after Holt) . : . 240
Egg of the Long Rough Dab, alive, and magnified : : . 246
Young Long Rough Dab, 12 inch long (after Holt) : : 5p ithe:
Egg of Common Sole, alive, and magnified ‘ : : 5 egy
Larva of Common Sole, newly hatched, alive, and magnified. ee 252
Larva of Common Sole, six days old, alive, and magnified : 255
Transition stage of Common Sole, alive, and magnified. ‘ we 253

Young Common Sole, just after its transformation, alive, and magnified. 254

Newly-hatched larva of the Thickback, alive, and magnified : 2 259
Egg of the Turbot, alive, and magnified (after McIntosh) . : a 202
Larva of Turbot, newly hatched (after Holt) 4 : ; = 202

Larva of Turbot, a little more than { inch long. From a_ preserved
specimen (after Holt) E é ; : : : veee260)

Larva of Turbot, a little more than + inch Jong, with spines on the head.
From a preserved specimen (after Holt). : : : 5 Ao

Transition stage of Turbot, $ inch long. From a preserved specimen
(after C. G. Joh. Petersen) . ‘ : : , : 5 ABS

Larva of Brill with two sides still similar (after Raffaele) . : s) 266
Larva of Brill with right eye nearly at the top of the head (after Raffaele) 269

Young Megrim or Sail-fluke, not quite $ inch long. From a preserved
specimen (after Holt) ; : : ; : ; 7S:

Young Scald-fish, 1 inch long. From a preserved specimen (after Holt) 275

Larva of the largest Top-knot, a little more than 2 inch long. From a
preserved specimen (after Holt) . : ° ; : ee 277

Head of the specimen shown in Fig. 129, viewed from the dorsal edge,
and showing the projecting spines in the region of the ears (after Holt). 277

Larva of Haddock, just after hatching : Z : : . 289

Larva of Whiting after absorption of the yolk. From a specimen hatched
in the aquarium (after Prince) : : : Z : 2 | 201

Newly-hatched larva of the Ling, alive, and magnified (after McIntosh) 296

Larva of Ling, thirteen days old, alive, and magnified (after Prince) . 297
Transformation stage of the Ling, # inch long (after Prince) : e297)
Egg of Hake, magnified (after Raffaele). : : : 5 299
Larva of Hake, newly hatched, magnified (after Raffaele) : E299

Young of the Three-bearded Rockling in the surface-swimming condition,
a little more than 2 inch long : ; : : : 5 aon

XVi LIST OF ILLUSTRATIONS
FIG. PAGE
139. Egg of the Striped Red Mullet (after Raffaele) 307
140. Larva of the Red Mullet (after Raffaele) 308
141. The egg of the Mackerel, alive, and magnified 314
142. Larva of the Mackerel, newly hatched, alive, and magnified 314
143. Larva of the Mackerel, four days old, alive, and magnified 315
144. Newly-hatched larva of the Long-spined Bullhead, alive, and magnified. 327
145. Egg of Red Gurnard, alive, and magnified . 33%
146. Young of Grey Gurnard, $ inch long (after Prince) 332
147. Larva of Grey Mullet, a little more than 2 inch long, alive, and magnified 335
148. Three of the eggs of the Angler, from a sheet of the spawn, alive, and

magnified (after Agassiz) 340
149. Larva of the Angler, newly hatched (after Agassiz) 341
150. Larva of the Angler, later stage of development (after Agassiz) . 341
151. Larva of the Angler at a very late stage, towards the end of its active

swimming condition . . ; ‘ 341
152. Eggs of the Cat-fish, natural size (after McIntosh) . 346
153. Newly-hatched larva of the Cat-fish, magnified (after McIntosh) . 347
154. Young living Cat-fish, $ inch long, reared in the St. Andrews Laboratory,

about 34 months old, just after the absorption of the yolk (after Prince). 348
155. Young Lump-sucker, 3 inch long (after Agassiz) 350
156. Newly-hatched larva of the Diminutive Sucker or Sea-snail 352
157. Foetus of an Indian Sting-ray (P/evopf/atea) as seen when the uterus is

cut open along its dorsal side (after Wood-Mason and Alcock) asy/
158. Developing egg of the Viviparous Blenny taken from the ovary Sept.

28th ; magnified 12 times (after Rathke) . 358
159. Young of the Viviparous Blenny, taken from the ovary of the mother

on Noy. 24th ; magnified twice (after Rathke) 358
Map I. Fishing Grounds of the British Islands. 5 : . . at end

Map II. West Coast of Europe. : : ; : . at end

le ouR ID ie Cle Nie sos de

PAA Ce LABLE MARINE FISHES

OF THE

Dil Sta tS ANS

(GGA Dea
HISTORY OF MODERN INVESTIGATIONS OF THE SUBJECT

OuR knowledge of the natural history of the majority of our
most valuable marine food-fishes is of quite recent growth, and,
although now there is a good deal of it, much more is still
required. When I write our knowledge, I mean that which
has been obtained and published, for the number of those who have
made that knowledge their own is small indeed. Those to whom
the study of nature is a familiar pleasure, or the regular work of
life, are not a large class. On the other hand, those who handle
fish continually in the course of their daily business, whether in
the boat or in the market, have, for the most part, not yet
realised that any knowledge concerning fish which they do not
possess can be of any value. It can scarcely be expected
that the fisherman or fish merchant will spend his short and
hard-earned leisure moments in the study of the blue books and
technical memoirs in which the results of research are described ;
and when certain newly-established facts are brought before
them in other ways, it frequently happens that they either
deny these facts as contrary to their own experience, or turn
a deaf ear from the conviction that such matters are of no
practical importance. With reference to the contradiction of the
naturalist’s conclusions, it may be urged that, although he may
not be able to climb the rigging of a smack, and is generally

BZ

4. MARKETABLE BRITISH MARINE FISHES CHAP,

sick while at sea, although also he may be as ignorant as a baby
of the mysterious and complicated practice of the fish trade,
still he has two advantages over the professional fish-man in
attempting to get at the truth concerning the life and habits of
fish. Firstly, he has been trained to appreciate the value of
scientific evidence, and is on his guard against jumping at
conclusions ; secondly, he can use instruments of precision,
which are as essential to the investigation of some of the
matters in question as the compass and the lead to the handling
of a fishing vessel. With regard to the practical importance of
the naturalist’s researches and results to the fishing industry, it
can only be said that there is no doubt about it. It is an un-
deniable fact that Parliamentary legislation and local bye-laws.
are at the present time constantly being demanded or proposed
for the benefit of the fisheries, and the reasons by which these
proposals and demands are supported consist largely of state-
ments concerning the natural history of the fishes and other
marine creatures concerned. It is necessary, therefore, that we
should be able to test the correctness of these statements, and
should be able to judge correctly of the most probable effect
of the measures proposed on the productiveness of the fisheries.

Before the year 1862 very little attention had been given by
experienced naturalists to the natural history of sea-fishes,.
particularly of those valuable in the market, There are, it is
true, numerous important books of older date in which fishes are
described, such as those of Yarrell and Couch, giving an in-
clusive account of British and Irish fishes. But the information
in these works concerning the habits and history of the fish is
scanty and not always correct. An important advance in our
knowledge of the herring was made in 1862, when Mr. Allman,
then Professor of Natural History in the University of
Edinburgh, at the request of the Scottish Fishery Board, made
a systematic investigation of the spawning of herring in the
Firth of Forth. The principal results of this inquiry are re-
corded in the Report of the Royal Commission on the Operation
of the Acts relating to Trawling for Herrings on the coasts of
Scotland, which Report was published in 1863. Professor
Allman dredged up the spawn of the herring from rough rocky
eround near the Isle of May at depths of 14} to 20 fathoms.
The eggs were firmly glued to stones, shingle, empty shells and

MODERN INVESTIGATIONS OF THE SUBJECT

at

coarse sand, and were found even on the backs of small living
crabs. The Report just mentioned contains a summary of all
that the Commissioners, two of whom were Dr. Lyon Playfair
and Mr. T. H. Huxley, could discover concerning the natural
history of the herring, but their conclusions were almost entirely
founded on the evidence afforded by the assertions of others,
evidence in the ordinary legal sense, not on circumstantial
evidence examined by themselves at first hand. Professor
Allman’s observations, however, have been confirmed and
extended since that time, and he was the first to establish the
fact that the spawn of the herring, like that of many shore fishes
and fresh-water fishes, adheres to solid objects in the water.

But one of the fundamental and most important facts
concerning the mode of life of sea fishes is that the spawn of a
great many of them is buoyant, and floats about invisible in the
waters of the sea. The story of the discovery of such spawn
was written by the discoverer himself in a very interesting
manner. But it was written in the Norwegian language, and is
only available for English readers in the translation provided by
the United States Commissioner of Fish and Fisheries, in one of
his bulky annual reports, that for 1877. In the year 1864 and
some following years, the Norwegian Government commissioned
Mr. G. O. Sars, a qualified naturalist of the Christiania University,
to carry out an examination of the cod-fisheries of the Lofoten
Islands, and of the natural history of the cod. In his report Mr.
Sars says that he had in former times heard from fishermen that
the roe of the cod could be seen floating in the water, and that it
was sometimes so abundant as to make the water thick. But he
knew that the eggs of many fresh-water fishes and of sea fishes
found near the shore were attached to stones or weeds, and he
knew that many kinds of lower aquatic animals swarm in the
surface waters of the sea. He supposed, therefore, that this
opinion of the fishermen was a mistake. However, when he
investigated the matter off the coast of the Lofoten Islands, he
found that the fishermen were perfectly right. The use of a
small, fine net towed through the water from a vessel is necessary
for the collection of all the more minute living things which
swarm in the waters of the sea, and which, making up by their
vast numbers for their small size, play such an important part in
the great drama of marine life. The principle of the net is very

6 MARKETABLE BRITISH MARINE FISHES CHAP.

simple. It may be made of cheap muslin or expensive silk
bolting cloth, but all that is required is a bag of any size made
of cloth of such texture that the water can pass through it, and
kept open at the mouth by a hoop of iron, brass, or wood. When
the net is hauled in, turned inside out, and its contents washed
into a jar of clean sea-water, living things of an extraordinary
variety and abundance are found. Among the material collected
by such a net Sars found a number of small, completely trans-
parent globules, which the microscope showed to be eggs of
some kind. These eggs became daily more abundant, until
about the end of March they were more numerous than any
other kind of thing in the sea-water. He was able to trace their
development, and found that a tender little fish was produced in
them, and at last hatched. He satisfied himself that these clear
elobules were really the spawn of the cod in the following way :—
Numbers of cod were caught which were full of roe, and ripe,
so that a little pressure caused the spawn to run out. He put
this spawn into clean sea-water. To quote his own words,
“This roe did not sink to the bottom, but floated on the water
like that which I had first observed. This peculiarity of the roe
of the cod-fish, to which no parallel is found in any other fish,
must be caused partly by the absence of the gluey matter which
in nearly all other fish holds the eggs together, partly by an un-
usually large quantity of fine oil contained in the egg, which makes.
the specific weight of the roe a little less than that of the water.
Only when the foetus is dead, and the egg shrinks in consequence,
does the roe sink to the bottom ; unless this is the case, it continues
to float in the water during the whole period of its development ;
and even the young fish recently hatched floats about in a similar
manner, with its umbilical bag attached to it, which for some time
supplies it with food.’ There was no difference at all between
the spawn taken from the fish and that obtained from the sea.
It appears from Sars’ report that in this first year he did not carry
out artificial fertilisation, but contented himself with comparing
the eggs in the sea with the unfertilised eggs obtained from the
female fish. The next year (1865) he continued his studies. He
kept numbers of the eggs in glass jars of sea-water till they were
hatched, and then kept the fry alive for more than two weeks.
The cod were very abundant this year, and in one region on a
calm day he found the sea covered with a thick layer of the

I MODERN INVESTIGATIONS OF THE SUBJECT 7

floating spawn. Sars took some ripe eggs from the fish and put
some milt into the water containing them, and found they were
impregnated. The outline of the embryo was seen in the eggs
eight days after the fertilisation, and in eighteen days the tender
little fish were hatched.

The Norwegian naturalist considered that in consequence of
the condition of this floating spawn enormous quantities of it
were destroyed by the waves, or washed ashore, or driven to
distant places by the currents and the wind. He suggests, there-
fore, that it might be worth while to direct large quantities of the
spawn to places where it would be safe from the wind and waves.

When he first became acquainted with it, Sars, as we have
seen, thought that the spawn of the cod was exceptional and
unique in its buoyant character. He soon found, however, that
this was by no means the case. He first found that the spawn of
the haddock was quite similar to that of the cod, and he also saw
three other kinds of floating spawn among the material collected
by his surface-net. In the summer of 1865 he visited the centre
of the mackerel fishery on the south coast of Norway, and found
that the eggs of the mackerel were also lighter than sea-water,
and floated about in the sea during their development. In
subsequent years the attention of Sars was given to the later
periods of the history of certain fishes, and to the general zoology
of the sea: he did not extend his investigations of the mode of
spawning much more widely. But the subject was taken up by
other observers. In 1868, Malm, a Swedish professor, of
Goteborg, obtained and artificially fertilised the eggs of the
common flounder. The object he had in view was rather to see
the earliest stages of development, than to make out the conditions
under which the spawn is naturally shed and developed. But in
his published account he stated that the eggs were small,
transparent, and globular, separate and free in the water. He
does not state that they floated, but remarks that when disturbed
they remained suspended in the water a long time. These
observations were made on the coast of one of the islands off
Goteborg, and, therefore, it will be noted the spawning flounders
were taken in the sea, not in an estuary or a river.

For some years after this no important additions were made
in Europe to the number of fishes known to produce buoyant
spawn, but in the United States of America Professor Alexander

8 MARKETABLE BRITISH MARINE FISHES CHAP.

Agassiz devoted special attention to the subject, collecting the
floating eggs and young stages of fishes at Newport. But it
was not till 1882 that he published an account of these obser-
vations. He then stated that he knew from personal observation
that the eggs of the majority of kinds of American flat-fishes,
and many other fishes, floated in the water. In Europe the
fact that the eggs of flat-fishes are of the buoyant kind was
confirmed by a German naturalist, Victor Hensen, who traced
the eggs of the plaice and flounder in the neighbourhood of
Kiel, in the Baltic, in 1882.

The study of floating spawn in this country commenced in
that part of it called Scotland in the year 1884. In that year
Professor McIntosh was carrying on observations for the infor-
mation of the Royal Commission on beam trawling, and I myself
was working independently at Granton, near Edinburgh. Pro-
fessor McIntosh observed the floating of the ripe, healthy eggs
of a large number of fishes, including the cod, haddock, whiting,
grey gurnard, common flounder, turbot, common sole, and lemon
sole, more correctly to be called lemon dab. ‘The present writer
in 1885 and 1886 published figures and descriptions of the float-
ing eggs of cod, haddock, and whiting, and of the plaice, flounder,
dab and witch. Since that time more detailed knowledge has
been obtained. But in referring to the year 1884, it is interest-
ing to turn to the Report of the Commission above mentioned,
issued in 1885, and read how confident and universal were the
assertions made by the professional witnesses as to the destruc-
tion of fish spawn on the sea bottom by the beam-trawl. Even
as recently as 1893, one of the witnesses most experienced in
the fishing industry told the Select Committee on Sea Fisheries
that, in his opinion, plaice spawn sank, and only after it had
matured to a certain point began to lift from the bottom.

The investigation of problems relating to the fisheries is not
of a kind to attract voluntary private effort. It does not promise
great individual rewards in the shape of either fame or fortune,
nor are the researches of that abstract philosophical kind which,
like virtue, are their own reward, and are therefore pursued for
their own sake with no ulterior object. The investigations of
Professor Allman and Professor Sars, which have been mentioned,
were undertaken at the instance of public authorities. But these
were special researches involving only temporary activity by a

I MODERN INVESTIGATIONS OF THE SUBJECT 9

single naturalist. Subsequently the necessity for co-operative
and continued inquiry was generally recognised, and permanent
institutions for the purpose were organised and supplied with
funds from public revenues. This happened first in foreign
countries, where governments are usually more ready to take
action in such matters than in our own.

The United States Commission of Fish and Fisheries was
started in 1871. It owed its existence to the knowledge,
enthusiasm, and influence of Mr. Spencer Baird, the Secretary
of the Smithsonian Institution, who was appointed Commissioner
without salary. The first Report was published in 1873, and
consisted of evidence concerning the decrease in value of the
New England fisheries, with papers on the history of certain of
the more valuable fishes. The second Report, dated 1874,
describes the commencement of the shad-hatching operations,
which have since taken such a large development.

The Reports have been issued annually up to the present
time, and in addition a Bulletin is also now published in
separate papers. The two series contain a vast amount of
information concerning the history of American fishes, and all
matters connected with American fisheries. The Commission
has further taken part with other public institutions in the
United States in the preparation and publication of a series
of quarto volumes containing a systematic and detailed de-
scription of the valuable aquatic animals and fishing industries
of the United States. In relation to our own sea-fishes and
sea-fisheries the results of the American investigations are often
instructive, particularly with regard to the kinds of fishes which
exist on both sides of the Atlantic. Many British and European
kinds, however, are absent from the American side, and therefore
the American literature does not supply so much material for
the summary which is given in the present work, as British and
European publications.

In 1870 was instituted by the Prussian Minister of Agri-
cultural Affairs the Commission for the Investigation of the
German Seas, which has its headquarters at Kiel. This con-
sisted of a small number of professors of Natural History, who
were supplied with funds for the expenses of organised re-
searches. They began by making voyages of investigation in
the Baltic and the North Sea, and in 1874 to 1876 carried out

fe) MARKETABLE BRITISH MARINE FISHES CHAP.

some most searching and fruitful investigations into the history,
habits, and breeding of the herring. The several branches of
the research were taken up by different investigators—one
studied the breeding grounds, and the conditions of the develop-
ment and growth ; another, the development of the egg from
the microscopical point of view ; another, the question of the
varieties of the herring. The results were published in complete
and fully illustrated memoirs, and these form the richest store
of knowledge concerning the herring which is up to the present
time in existence. In more recent years the Reports have dealt
with various matters connected with the science of the sea, but
have not had so direct a bearing on the history of particular
food-fishes.

In the years between 1870 and 1880, little or nothing was
done in this country towards the elucidation of the history of
sea-fishes. The amount of knowledge of the subject which was
available at the end of this period, and just before the com-
mencement of the systematic and special investigations which
have been carried on in recent years, can be ascertained by the
examination of three general summaries which were published
at that time, and of which a brief review may be here given.

In the year 1878 the celebrated Frank Buckland and
Mr. Spencer Walpole, at the time Inspectors of Fisheries for
England and Wales, under the Home Office, were specially
commissioned by the Home Secretary to make inquiries into
questions relating to the fisheries. They published a Report in
187g which, in consequence of the fact that one of the Com-
missioners had long made a special study of the subject in
question, is of greater value than the majority of biue books. In
this Report Mr. Buckland gives in two Appendices a summary
of all that was known at the time, so far as he could discover,
concerning the lives and habits of our commercially valuable
sea-fishes. In the Report the following statements are found :—

“ The greatest ignorance prevails about the habits of sea-fish.
Speaking generally little is known of the seasons in which they
spawn, of the places in which they cast their spawn, and still
less of the time which the spawn after it is cast takes to vivify.
Nobody, so far as we have been able to ascertain, has ever seen
the eggs of soles, turbot, plaice, and other like fish after their
extrusion under natural circumstances from the parent fish. A

I MODERN INVESTIGATIONS OF THE SUBJECT Tel

little more is known about the spawning of round fish. The
spawn of the herring is certainly attached to small shells, sea-
weed, and other substances at the bottom of the sea. Professor
Sars has apparently proved that the spawn of the Gadide
floats on the top of the water. The same thing has been
shown by the Hon. S. F. Baird, of the United States Fishery
Commission. .. . With these exceptions little is known of the
spawn of sea-fish.”

The Report goes on to state that more was known concern-
ing the habits of the fry ; that most young fish frequent the
shallow, sandy, or muddy plains which are adjacent to the sea-
coast, or the mouths and estuaries of rivers. But a study of the
Appendices already mentioned shows how meagre was the
supply of accurate information from which Buckland was able
to draw at that time.

In 1880 was published 7%e Natural History of British Fishes,
by Frank Buckland. It consists of a popular account of each
fish in alphabetical order, and contains a considerable amount
of information, interspersed with anecdotes and personal ex-
periences in the author’s well-known manner. But from a serious
point of view it is by no means so important as the official
Report of 1879, already mentioned.

Dr. Francis Day’s Feshes of Great Britain and Ireland was
issued in parts from 1880 to 1884. It is enriched with fine
lithographic plates from his own drawings of every British and
Irish species known to the author. It contains a vast amount
of information, and is one of the most valuable books of
reference accessible to the student of the fishes of the British
Islands. But with regard to the life histories of the fishes the
information given is far from satisfactory, and by no means well
arranged. It deserves mention here that both Buckland and
Day were largely indebted to the personal observations of Mr.
Matthias Dunn, of Mevagissey, in Cornwall, who throughout a
long and busy life has perseveringly and very fruitfully applied
himself to the careful study of the habits and life histories of
the denizens of the waters near his home, and has made good
use of the exceptional opportunities for collecting which the
harbour of Mevagissey affords.

The systematic investigation by modern methods of questions
relating to the fish-supply began in this country with the estab-

12 MARKETABLE BRITISH MARINE FISHES CHAP.

lishment of the new Fishery Board for Scotland in 1882. The
old Fishery Board, whose official title was the Board of British
White Herring Fishery, was dissolved. The first members of
the new Board were :—Sir Thomas J. Boyd, chairman ; John
Guthrie Smith, Sheriff of Aberdeen, Kincardine and Banff, deputy-
chairman ; George H. Thoms, Esq., Sheriff of Caithness, Orkney
and Shetland ; Alexander Forbes Irvine, Esq., Sheriff of Argyle ;
Sir James Ramsay Gibson- Maitland, Bart. ; Stephen William-
son, Esq., M.P.; Professor Cossar Ewart, M.D. ; James Maxtone
Graham, Esq.; James Johnstone Grieve, Esq.; Mr. Dugald
Graham, secretary ; Archibald Young, Esq., Advocate, Inspector
of the Salmon Fisheries of Scotland.

The new Board being not only required to make suggestions
for the improvement of the Fisheries, but being empowered also
to take such measures for their improvement as the funds under
their administration and not otherwise appropriated might admit
of, and taking into consideration also the important practical
results obtained by the U.S. Commission of Fish and Fisheries,
decided to institute investigations into the habits and life-history
of some of the more important food-fishes, such as the herring
cod, ling, haddock, mackerel, sole, plaice, and flounder.

The following questions are mentioned in the First Annual
Report, 1883, as deserving careful investigation :—

(1) The food, life-history, distribution, and migrations of

useful fishes.

(2) The nature of the feeding and spawning grounds of food

fishes.

(3) The period of spawning, nature of the ova, the time

required for, and the conditions favourable to, hatching.

(4) What means can be adopted for the protection of fish

during their early stages of growth, and what can be
done to prevent the destruction of immature fish.

(5) What new useful fishes (such as the American shad and

the land-locked salmon) can be introduced, and how far

the supply of our present forms can be increased by
artificial cultivation or protection during the spawning
period.

(6) The influence of atmospheric variations, and of the
changes of the temperature of the water, and of cur-
rents, on the presence and migrations of fish, and the

I MODERN INVESTIGATIONS OF THE SUBJECT 13

nature and depth of the water where fish commonly
abound,

(7) The special enemies of useful fishes, and the causes of

the disappearance of fish from certain districts.

As the artificial cultivation of cod or other fish required more
appliances than the Board could command, they determined to
commence with the investigation of the food and early life-
history of the herring. They therefore applied to the Home
Secretary to ask the Lords of the Admiralty to grant the use of
asteam pinnace. The application was declined.

From the Second Report of the Board, giving its proceedings
in 1883, published in 1884, we learn that in the late summer of
1883 the Admiralty consented to the use of the /acka/, a steamer
usually employed in fishery protection service, for a preliminary
inquiry into the herring and herring fishery. The expenses of
this inquiry were to be met out of the sum voted for travelling
expenses, and a small wooden laboratory on the coast of Ross-
shire, belonging to Mr. Romanes and Professor Ewart, was lent
by them for the work of the Board.

At the suggestion of Professor McIntosh, of St. Andrews,
who has been all his life a keen student of marine zoology, the
Board agreed to co-operate with him in providing for the
expense of fitting upa small building on the shore there asa
marine laboratory, in which researches on food-fishes could be
carried on. With the sanction of the Treasury a sum of £335,
was devoted by the Board to this purpose, and Professor
McIntosh commenced experiments and observations on the
floating eggs of flat-fishes, The Scientific Appendix to this
Report includes a note by Professor McIntosh on these earliest
researches at the St. Andrews Laboratory, consisting of the
artificial fertilisation of the eggs of the cod and flounder and a
few other fishes.

In March, 1884, Professor Ewart made an examination of
the Ballantrae Bank, reputed to be a herring spawning bed. It
was found to be covered with herring spawn, and the results of
this examination were the most valuable obtained up to that
time by the scientific inquiries of the Board.

The Treasury only sanctioned £900 for the scientific work
from funds already in the hands of the Board, chiefly herring-
brand fees. £300 of this was required to meet expenses already

{4 MARKETABLE BRITISH MARINE FISHES CHAP.

incurred, £335 for St. Andrews, so that, the balance being very
small, scientific work was almost suspended in the summer of
1884.

In 1883 a Royal Commission was appointed to inquire into
the injuries alleged to be inflicted upon line and drift-net fisher-
men by the use of the trawl-net and beam trawl in the territorial
waters of the United Kingdom. A sum of £200 was granted to
this Commission for the purpose of conducting scientific obser-
vations upon the results of the use of the beam trawl ; and in
January, 1884, Professor McIntosh was appointed to make
these observations. The members of this Commission were :—
John William, Earl of Dalhousie; Edward Marjoribanks,
MUP: ; Thomas Henry Huxley, F-R.S.¢.- William “Spresten
Caine, M.P.; Thomas Francis Brady. Ninety-three hauls of
the trawl on board an ordinary steam trawler were made under
the observation of Professor McIntosh, who reported to the
Commission in November, 1884. His report was printed as
an appendix to the Report of the Commission, published
in 1885.

Professor McIntosh’s cruises were made off the mouth of the
Firth of Forth and off Aberdeen. Three days were also spent
in trawling in a private steam yacht off Scarborough, and two
days in St. Andrews Bay, in the J/edusa, belonging to the
Granton Marine Station. His report contains a deal of infor-
mation, though, as might be expected, it is by no means so
precise as that obtained by subsequent researches of a similar
kind. It contains tables showing the fish captured in the various
hauls under three heads—saleable fish, immature fish, and un-
saleable fish. The latter title applies only to those species of
fish which are entirely unmarketable, for which there is no
demand for any commercial purpose: they are the frog-fish
(Lophius piscatorius), two kinds of dog-fish, and a few common
shore fishes of small size. The title “immature fish” is applied
to those individuals of marketable species which were so small
as to be useless for the market, and therefore has no reference
in this Report to the condition of the fish with respect to spawn-
ing.

Thus all that can be got from the tables is the proportional
numbers of the individuals thrown overboard after capture, and
of those kept for the market. On the fishing grounds where

I MODERN INVESTIGATIONS OF THE SUBJECT 15

the observations were made true soles are very scarce—only 78
were taken, and none were rejected ; also of turbot and brill none
came under the heading “immature.” One-fourth of the total
number of plaice captured were rejected from their small size ;
while of common dabs and long rough dabs, ten times as many
were thrown overboard as were taken to market, these being rather
small fish even when adult. However, the actual waste of fish
of valuable kinds—with the exception of common dabs and long
rough dabs, which are of very little commercial importance—
is shown to be very small indeed. The only species in which
the waste, if the small specimens do not survive when returned
to the sea, is serious, is the plaice.

The Report of the Commission itself was a 1 most important one,
not only from the nature of its conclusions and recommendations,
but from the fact that many of them have been put in force by
legislation. It is worthy of note that, in consequence of ill-
health, Professor Huxley was unable to take any part in
drawing up the Report, and therefore did not share in the
responsibility for its conclusions and recommendations. The
Report states that, in the absence of reliable statistics by means
of which the then supply of fish could be compared with that of
previous periods, the Commission was unable to estimate the
degree to which diminution had taken place, although it con-
sidered that the supply of certain kinds of fish in certain places
in the territorial waters had diminished in recent years. The
Commission recommended that statutory powers and means
should be given to the fishery authorities to enable them to
collect fishery statistics. It was of opinion that the productive-
ness of the fishery grounds should be regularly and periodically
examined by competent persons, and that all circumstances
bearing upon fishery questions should be systematically investi-
gated. The Commissioners thought that the proposed investi-
gations of the Scottish Fishery Board were of a useful and
practical character, and worthy of the expenditure of public
money. They recommended that experiments should be made
to test the effect of trawling, and for this purpose power should
be given to the authorities to prohibit trawling in territorial
waters when and where they thought fit. Scotland and Ireland
possessed Fishery Boards, but England had no analogous
authority. Such an authority, the Commission declared, should

16 MARKETABLE BRITISH MARINE FISHES CHAP.

be created for England at once; and on it, as well as on the
Scotch Board, should be conferred the regulating powers already
possessed by the Irish Board. They also thought that one
central authority should be created for the United Kingdom,
but in the meantime the Scottish Board should have the
powers and funds it asked for. The latter recommendation has
been carried into effect, but the former has been neglected. The
Commission recommended that, as a temporary measure, the
large powers of a fishery authority in England should be con-
ferred upon the Secretary of State for the Home Department,
or on the President of the Board of Trade.

On the 31st March, 1884, the Marine Biological Association
of the United Kingdom was founded and constituted at an
influential meeting held in the rooms of the Royal Society, at
Burlington House, London. Professor Huxley was its first
president, and Professor E. Ray Lankester, who initiated the
movement, became its honorary secretary. The Association
immediately set about choosing a site for a well-equipped and
permanent marine laboratory. The site chosen was one granted
to the Association by the War Office, on the Citadel Hill,
Plymouth, where the laboratory now stands. At the first
annual meeting of the Association in 1885, subscriptions to
the amount of £8,000 were announced; in 1886 the amount
reached nearly £15,000 including £5,000 from H.M. Treasury ;
and in 1887 the laboratory was aimost finished, and active
work was commenced.

In October, 1884, the sum of £1,000 was placed by the
Government from the Public Treasury at the disposal of the
Scottish Fishery Board for scientific investigations. During the
previous summer the scientific work of the Board had been in
great part suspended. Nevertheless the Marine Station at St.
Andrews was completed in the autumn of 1884, and researches
into the natural history of food-fishes commenced there. In the
same autumn Professor Cossar Ewart was sent to the United
States to study the methods and operations of the Fish Com-
mission of that country. In January, 1885, Mr. George Brook
was appointed as a salaried naturalist to work under the instruc-
tions of the Board, and under his supervision a wooden marine
laboratory was erected at East Loch Tarbert, on the Firth of
Clyde. The Board had also the use of the Rothesay Aquarium

—

I MODERN INVESTIGATIONS OF THE SUBJECT Wy

for biological observations and experiments, and a small wooden
laboratory on the shore of Cromarty Firth on the east coast of
Scotland. Thus at the beginning of 1885 the Board had no
less than four marine stations for investigation, besides the
resources of the Natural History Department of Edinburgh
University.

The investigations carried on in 1884-85 were principally
observations on the spawning of herring and cod at Rothesay.
These observations were published in the Board’s Third Annual
Report for 1884. A number of cod were observed spawning in
March in the Rothesay Aquarium, and the eggs were found
floating at the surface of the tanks ; the fish merely swam about
at random while shedding the eggs and milt. The same Report
contains an account of the Marine Laboratory at St. Andrews,
and work done there, the latter consisting of observations on the
eggs of the viviparous blenny and other useless fishes, and on
the eggs of the herring, the young of the ling, of the eel, and of
cod. Mr. Brook contributes some notes, the most important of
which is a short paragraph stating that certain eggs, sent by
fishery officers attached to zoophytes, were not herring eggs. In
the Second Report of the Board such eggs were figured as those
of the herring, and important conclusions drawn from. their
occurrence as to the period during which herring were spawning
on the East of Scotland. It is necessary to note this and other
errors and their rectification, as showing the ignorance of essential
facts which has obtained, and the need of patient research
and experience for the gradual attainment of trustworthy
information.

In the same year 1884 was opened a Marine Station on a
small scale at Granton, near Edinburgh. The origin of this
enterprise was the grant to the Scottish Meteorological Society
of the surplus money from the Edinburgh Fisheries Exhibition
of 1882. At the time both that society and the Fishery Board
were anxious to carry on scientific investigations into questions
affecting the sea fisheries. The Granton Station was organised
and governed by Dr. John Murray, subject to the approval of
the Scottish Meteorological Society. The establishment con-
sisted at first of a small floating laboratory and a steam yacht,
the Medusa, fifty-one feet in length. For some years, besides
Dr. Murray himself, four scientific observers worked for this

C

18 MARKETABLE BRITISH MARINE FISHES CHAP,

institution—the present writer and Mr. Henderson in zoology,
Mr. Rattray in botany, and Dr. Mill in chemistry and physics.

The work of the Granton Station was of a more academic
and less practical character than the work at that time carried
on by the Scottish Fishery Board. I was engaged in the in-
vestigation of the eggs and development of sea-fishes, including
food-fishes. In the summer of the same year I described for
the first time in this country a pelagic egg and larva, afterwards
proved to belong to the sprat. In the autumn I artificially
fertilised herring eggs on the coast of Northumberland, and
published a contribution to the knowledge of their development
in the Quarterly Journal of Microscopical Science. In 1885 I
published a paper on the pelagic eggs of the cod, haddock,
whiting, and gurnard, the first account with exact measurements
and figures of the pelagic eggs of these fishes in this country.
Professor McIntosh described pelagic eggs of these and other
fishes in the Trawling Commission’s Report in 1885, and a short
note in 1884, but without figures. In 1886 I published a com-
prehensive survey of the work done up to that time in the
development of marine fishes. In the same year I also pub-
lished the discovery of the hermaphroditism and the nature of
the egg capsule in Myxine glutinosa, the hag-fish, which is so
troublesome an enemy to fish and line fishermen on the north-
east coast.

In 1887, I transferred my services to the Marine Biological
Association at Plymouth, and since then little work of direct
utility to the fisheries has been done by the Scottish Marine
Station, the other members of the staff having been already
obliged to seek more remunerative posts in 1885 and 1886.
The work of the J/edusa has, however, been continued on the
west coast of Scotland by Dr. Murray and many men of science
who have co-operated with him ; and research has been con-
tinued from time to time both at Granton, where a laboratory
on shore was obtained, and at Millport on the Clyde, to which
place the floating laboratory was transferred ; these researches
have resulted in large additions to the knowledge of the marine
fauna of the Clyde and to other branches of marine science.

A considerable amount of work was accomplished under the
auspices of the Scottish Fishery Board in the year 1885-86, the
principal contributors being Mr. Brook, Professor Ewart, Pro-

I MODERN INVESTIGATIONS OF THE SUBJECT 19

fessor McIntosh, and Mr. Duncan Matthews. Mr. Matthews
made an elaborate investigation into the question of varieties
among the herrings of the Scottish coasts, with the object of
ascertaining how far examination of these herrings confirmed
or contradicted the conclusions reached with regard to the
herrings of the Baltic by Dr. Heincke, of the German Fishery
Commission, working at Kiel. The report of Mr. Matthews in
the Fourth Report of the Board is very detailed and valuable,
though it by no means settles the question. The most important
items of the rest of the work, the results of which are published
in the same Report, are observations on the herring fishery of
Loch Fyne, determination of the species of Copepoda and other
animals taken in Loch Fyne, valuable Reports on the food of
the herring, cod, and haddock, by Mr. Brook, and a Report on
the proportion of herrings and sprats in Thames and Forth
whitebait. Work was also carried on at St. Andrews Labora-
tory by Professor McIntosh and Mr. Prince. The results of
these inquiries are described in the Board’s Fourth Report,
published in 1886. In the same Report it is stated that, in
consequence of the recommendations of the Beam Trawling
Commission, above summarised, the Sea Fisheries (Scotland)
Amendment Act, 1885, was passed, conferring upon the Scotch
Board power to prohibit by bye-law trawling or any other mode
of fishing in any part of the territorial waters of Scotland.
Under this Act the Board made a bye-law prohibiting trawling
in the Firth of Forth, St. Andrews Bay, and Aberdeen Bay, as
an experiment for the purpose of ascertaining the result of the
prohibition on the supply of fish on the grounds so protected.
The Board then applied to the Treasury for funds to enable
them to purchase a small vessel for trawling. The sum of
43,000 was granted, and the steam fishing-yacht Garland was
purchased at the price of £2,500. This vessel was 92 feet long,
15 feet 10 inches beam, and 84 feet draught. She was built of
iron. She was fitted with a trawl of 25 feet length of beam,
with which she was to trawl over the protected grounds in order
that the number of fish obtained from them at different times
might be carefully and accurately ascertained.

In the Board’s Fifth Report, published in 1887, an account
is given of the operations of the Garland. It was decided not
to close Aberdeen Bay any further, but by new bye-laws the

( 2,

20 MARKETABLE BRITISH MARINE FISHES CHAP.

territorial area in the Moray Firth was closed, and the Firth of
Forth and St. Andrews Bay areas were extended. Mr. W. L-
Calderwood acted as naturalist on board the Garland, and Mr.
Duncan. Matthews superintended the course of the trawling
observations from the University of Edinburgh, collating and
tabulating the returns forwarded from the Garland. Mr. Brook
had charge of the work on the west coast, while Professor
McIntosh continued his studies on the life-histories of food-
fishes at the St. Andrews Laboratory. Beyond the records of
the experimental trawling observations, the description of scien-
tific investigations forming Appendix F to the Fifth Report
does not contain much of great magnitude and importance.
Mr. Matthews contributes a second elaborate report on varieties
found among herrings from the east coast of Scotland. He also
gives an elaborate description of the skeleton of the herring.
Additional papers on the food of fishes are given, namely of the
whiting and young Gadide. The statistics of fish taken by the
Garland, and landed by ordinary boats, are given in a number
of detailed tables occupying 157 pages.

In 1886 certain departmental changes were made in the
English public service with respect to business connected with
the fisheries. The jurisdiction of the Home Office in respect of
salmon and fresh-water fisheries was transferred to the Board of
Trade by the Salmon and Fresh-water Fisheries Act, 1886. A
Fishery Department of the Board of Trade was organised, at
the head of which was placed an assistant secretary (Mr. G.
Swainston). Mr. Berrington and Mr. Fryer, the inspectors of
Fresh-water Fisheries at the Home Office, were transferred to
the new department, and a third inspector (Mr. Malan), specially
for sea fisheries, was also appointed. The new department
publishes annually a return of statistics of sea-fish landed on the
coasts of the United Kingdom, and a Report on the Sea
Fisheries, in addition to the Report on Salmon and Fresh-water
Fisheries, which was continued. But the department “as no
power to make scientific tnvestigations, nor to make bye-laws or
regulations affecting the sea fisheries.

The anomalous position of fishery affairs in England and
Wales has been since still further increased by the Sea Fisheries
Regulation Act of 1888, which is of a permissive character, and
allows the Board of Trade to create Sea Fisheries Districts on

I MODERN INVESTIGATIONS OF THE SUBJECT 2m

the application of county or borough councils, to be under the
jurisdiction of district committees formed partly by members of
the county or borough councils, partly by outside members,
The powers of such district committees are larger than any
previously exercised by the Board of Trade. They can make
bye-laws to regulate the fishing in the territorial waters of their
district to any extent they please, and provide for their expenses
out of the local rates. Such Sea Fisheries Districts have now
been created round nearly the whole coast of England and
Wales.

In August, 1887, the Marine Biological Association issued
its first publication, the first number of its journal. This number
contained a full description, with plans, of its fine laboratory at
Plymouth, and a valuable detailed description of the fishing
industry at the port of Plymouth by Mr. Walter Heape. The
second number, issued in 1888, contains a paper on some pre-
liminary investigations made by myself, on the local fauna and
the ova of food-fishes. In this first paper was already solved
the mystery of the male sole, and the question of the reproduc-
tion of that species, previously unknown. In 1885 it had been
stated to the Beam Trawling Commission that no one had ever
seen a male sole, that the female soles were caught, but not the
males. It was found that the male soles were abundant enough,
but had simply not been recognised, and I artificially fertilised
soles’ eggs for the first time.

In the Sixth Report of the Scottish Fishery Board, published
in 1888, the chief feature is again the statistics of the Garland
relating to trawling, and to the abundance of fish in areas where
trawling was prohibited. The data are too voluminous to be
easily discussed here ; but it is interesting to note that those
who directed the observations were beginning to see that some-
thing more was required than merely collecting and comparing
the totals of the fish captured. It was found that in 1887 more
flat-fish were taken in the closed areas than in 1886. But it
may, reasonably be objected that in these two years the Fishery
Board did not fully understand the problem which had to be
solved. It prohibited trawling in certain areas, and then made
observations to see if the fish increased in these areas. Asa
result the Scotch Board points out that the number at least of
flat-fish was greater. The result in other words was that if fish

22 ‘MARKETABLE BRITISH MARINE FISHES CHAP.

were not caught they would remain in the sea. The problem
that has to be solved appears to be a different one; it is, how
can we maintain the total annual yield of the sea fisheries? It
is a very simple remedy for the diminished yield of the fisheries
to leave off fishing, and one not likely to be adopted while a
margin of profit remains. The question is whether by certain
particular restrictions the general supply can be increased, or at
least prevented from diminishing, and this question was not at
that time answered by the Scottish Board. It must on the
other hand be admitted that the Board had some reason on its
side in considering the question of trawling in relation to terri-
torial and inshore waters, and how it affected the fishing which
previously went on at scattered villages along the coast.

Perhaps the most important results of the operations of the
Garland were the information subsequently obtained from her
operations under Dr. Wemyss Fulton’s guidance with regard to
the life-histories of valuable fishes. The shorter papers included
in the Sixth Report are of no striking importance ; but one
tracing the colour of “red cod’—ze. the discoloration of dried
cod-fish—to microbes, deserves mention.

The work of the Scottish Fishery Board in 1888, described
in the Seventh Report, 1889, consisted, firstly, of a continuation
of the laborious observations on the condition of the inshore
fishing grounds, where trawling was prohibited ; some observa-
tions on the “spawning grounds” of plaice and other fishes ;
systematic inquiries into the distribution and capture of imma-
ture fish ; an examination of the trawling grounds to the west of
the Hebrides, and certain special inquiries. In this year and
the preceding, the scientific work was under the control of a
Committee of the Board ; and Dr. Wemyss Fulton, who began
to work for this Committee in 1887, acted in 1888 as secretary
to the Committee, and was entrusted with the organisation of
much of the fishery research with very satisfactory result.

The fully equipped operations of the Marine Biological
Association at the Plymouth Laboratory commenced in June,
1888 ; the staff consisting only of the Director of the Labora-
tory, G. C. Bourne, Esq., Fellow of New College, Oxford ; his
assistant, W. Garstang, Esq., B.A.; and the present writer. It
should be clearly pointed out that the declared object of the
founders of the Marine Biological Association was “to promote

I MODERN INVESTIGATIONS OF THE SUBJECT 23

researches leading to the improvement of zoological and
botanical science, and to an increase of our knowledge as
regards the food, life-conditions, and habits of British food-
fishes and molluscs” ; and this double purpose of pure scientific
investigation on the one hand, and of special fishery study on
the other, has been strictly adhered to by the Council in its
management of the funds at its disposal. The Fishmongers’
Company contributed £200 a year, raised later to £400 a year,
to the Association, whilst Her Majesty’s Government have given
#500 a year in the years 1888-89, 1889-90, 1890-91, and £1,000
a year in the years following, Private individuals have given
annual donations of £200 and upwards to promote special
researches, and contributions have been received from other city
companies and from the Royal Society. Besides the investigations
noted in the present chapter, which have contributed largely to our
knowledge of food fishes, the Plymouth Laboratory has to reckon,
as a no less important outcome of its activity, a long list of scien-
tific memoirs on the embryology and anatomy of marine organisms
of all kinds, the result of researches made within its walls by
British and foreign naturalists who have availed themselves of
the facilities for study there provided.

In 1890 were published two elaborate memoirs on the
development and life-histories of food-fishes, namely, “The
Development and Life Histories of Teleostean Fishes,” by Prof.
McIntosh and Mr. E. E. Prince (Tvaus. Roy. Soc. Edin. xxxv.,
3), and “A Treatise on the Common Sole,” by myself. Of the
first memoir, which is somewhat voluminous, the first ten sections
have little direct bearing on fisheries, treating of the development
of the eggs of fishes as a purely zoological subject. Section XI. is
devoted to the embryonic larval and post larval stages of fishes
and forms a valuable contribution to our knowledge of the eggs
of fishes and the earliest condition of the young after hatching
Section XIII, the last, is one of the most important, giving a
full account of the previously unknown eggs and development of
the cat-fish, Azarrhichas lupus, a fish which is common on the
east coast, and sometimes eaten, though not of great value in the
market. The memoir is illustrated by twenty-eight lithographed
plates.

My memoir on the sole is illustrated by eighteen plates, to
the production of which very great labour and expense were

24 MARKETABLE BRITISH MARINE FISHES cua

devoted. Nine of the plates are finely-executed chromo-
lithographs, prepared from water-colour drawings made from life
by an artist specially employed for the purpose. These plates
illustrate the characters and appearance of the four British
species of sole, the changes in the colour of the common sole on
different grounds, and the position and relations of the breeding
organs in their natural position as seen on dissection. The other
plates illustrate the anatomy of the sole, and the eggs and
transformations of the young in this and other species of flat
fishes. The latter two sections of the four into which the memoir
is divided contain a full and careful discussion of the natural
history of the sole, and the bearings of this upon the production
of soles for the market. The artificial propagation of the sole,
which has been carried out only at the Plymouth Laboratory, is fully
considered, and is shown to be beset with certain difficulties not
met with in connection with other kinds of food-fish. These
difficulties are chiefly caused by the remarkably small size of the
male breeding organs or milts in the sole, a peculiarity to which
was due the fact that previous observers failed to recognise the
male sole at all.

We find from the Eighth Annual Report of the Scottish
Fishery Board, published in 1890, that in 1889 the scientific
work had been entirely superintended by Dr. Wemyss Fulton,
acting under the instructions of the Board, the Scientific
Committee having ceased to act. In this Report the trawling
observations are discussed on the usual plan for the year 1889
and show a distinct decrease of fish in the closed areas—a
somewhat different result from that originally anticipated. The
most important part of the Report is Dr. Fulton’s paper on the
“ Distribution of Immature Fish and their Capture by different
Modes of Fishing,” based upon observations specially made by
the Board’s investigation steamer Garland. ‘This paper contains
the first attempt made to ascertain the szze at which each species
of food-fish becomes mature—that is, the size at which it breeds
for the first time. This was done merely by finding the sizes
recorded of the smallest ripe, or nearly ripe, specimen of the
various species examined. The distribution of the fish above
and below these limiting sizes is lucidly described, and we have
here the first contribution of importance to our knowledge of
the differences among the different kinds of fish as to the regions

i)

I MODERN INVESTIGATIONS OF THE. SUBJECT

inhabited by the young. It was previously stated that the inshore
grounds were nurseries for young fish. It was now proved that
this is true only of certain kinds of fish, and especially of the
plaice. Another important contribution by Dr. Fulton deals
with the relative numbers and sizes of the sexes in food-fishes.

The Report of the Board for 1890, published in 1891, contains
nothing very novel, but important continuations of the investi-
gations described in the preceding volume of the series. The
records of the trawling experiments of the Garv/and are continued,
and also some special fishery statistics in continuation of those
of former years. Dr. Fulton publishes a second paper on
immature fish, giving the result of an experimental investigation
of the problem whether the small fish are killed by capture in the
great trawl or in the shrimp trawl, or whether they are alive and
survive if returned to the sea. He concludes that in great trawls
the flat fish are usually alive and not killed while the round fish
are fatally injured, and that in the shrimp trawl the small fish
captured are uninjured.

In the year 1890 an important fishery survey was organised
in Ireland. The Royal Irish Academy had in previous years
made explorations of the sea-bottom off the south-west coast of
Ireland by the agency of the Rev. W. Spotswoode Green. In
1887 the Royal Dublin Society, whose function is to promote
industries, rather than pure science, began to utilise Mr. Green’s
services in the examination of the condition of the fisheries in
the south and west of Ireland. At the end of 1889 the Chief
Secretary for Ireland approved of a suggestion that the Society
should organise a survey with the object of ascertaining the
amount and distribution of the fish supply on the west coast.
The estimated cost was found by the Society to be 41,200 per
annum for two years, and the Government agreed to provide
half the money, the Society the other half. The execution of
the project was entrusted to the Rev. W. S. Green, who con-
ducted a fishery surveying cruise in the ss. /’zmga/ in the spring
and summer of 1890. Mr. Green was appointed director of the
Survey, Professor Haddon, naturalist, and Mr. T. H. Poole,
C.E., surveyor. As the survey was commencing, Mr. Green
was appointed one of the inspectors of Irish Fisheries, but this
‘made no difference in the plans. A narrative of the first cruise
was published in the Report of the Royal Dublin Society for

26 MARKETABLE BRITISH MARINE FISHES CHAP,

1890; but the complete results of the two years’ work were not
published till 1892, when they were printed in the Report of the
Council of the Society for 1891, and in the Proceedings of the
Society. This statement of results, under the title, “ Report on
the Results of the Fishing Operations of the Survey,” was
prepared by Mr. Ernest W. L. Holt, who bore the principal share
in the natural history work in the two cruises of 1890 and 1891.
The plan of operations in the natural history department was
devised by Professor Haddon, and he took charge of the work
on board ship for two months in 1890, but not in 1891. Mr.
Holt’s Report consists first of a list of the stations examined,
with a list of the fish caught at each, and an indication of the
invertebrates taken with them; secondly, of a record of all the
fish caught under the heading of each species ; thirdly, of a
discussion of the scientific evidence on economic questions
afforded by the examination of these fish. In this last part of
the Report we have the determination for the west coast of
Ireland of (1) the spawning period of fish and the distribution
of the spawning fish ; (2) the limiting sizes of immature fish and
comparison of the habitats of mature and immature fish ; (3) the
effect of different nets upon the capture of immature fish ;
(4) the food of fishes. With respect to the definition of
immature fish in the several species, Mr. Holt makes an im-
provement on Dr. Fulton’s method. Dr. Fulton ascertained the
smallest size of ripe and nearly ripe fish without regard to sex,
but mentions at the same time that the smallest ripe specimens
in nearly all instances were males. Mr. Holt gives tables in
which the greatest and least lengths of ripe and nearly ripe speci-
mens are recorded for the two sexes separately, and then in
discussing the distribution of mature and immature forms,
divides them by the size of the smallest ripe female. Mr.
Holt’s report also contains in many cases information as to
the habitat of the very young individuals of several species
which do not pass their young stages in shallow water, and
which in these stages had not been obtained before—e.g.,
lemon sole (Pl. microcephalus), pole dab (PZ. cynoglossus), and
others. Mr. Green at first announced that the young of such
forms obtained in very deep water were the young of the
common sole; but when this conclusion was challenged by
myself from my own experience, the mistake was discovered

ee

I MODERN INVESTIGATIONS OF THE SUBJECT DY

and acknowledged. The results obtained by the Survey are
very valuable, and will form a most useful basis for attempts to
develop the deep-sea fishery on the west coast of Ireland. If
the Government had provided means for a similar survey of the
east coast of England and the North Sea, the result would have
gone very far to settle the question of immature fish which was
agitating the industry in that region. As it was, the con-
clusions obtained on the east of Scotland and the west of
Ireland could not be applied directly to the east of England,
and in consequence the Marine Biological Association en-
deavoured, with a single naturalist (Mr. Holt) and without a
surveying ship, to do there what was thoroughly done with
special Government aid on the west of Ireland.

In the Tenth Annual Report of the Scottish Fishery Board,
published in 1892 and relating to 1891, much space is as usual
occupied by the tables of records of the statistical observations
made by means of the Garland and otherwise. The trawling
experiments of the Garland showed again a_ considerable
decrease in the abundance of food-fishes in the waters of the
Firth of Forth and St. Andrews Bay, closed against beam-
trawling. Following are extracts from Dr. Fulton’s remarks :—
“Tt is clear:from the analysis of the results of the trawling
experiments since 1886, that the prohibition of beam-trawling
within the Firth of Forth and St. Andrews Bay has not been
followed by the increase in the abundance of flat fishes
within these waters which was anticipated.” As an explanation
it is pointed out that the spawning fish do not spawn in the
protected waters, but are on the other hand captured outside by
the trawlers ; and that immature fish of the majority of species
are to be found in greatest numbers outside the territorial limit
up to a distance of ten or twelve miles from shore. In the same
Report Dr. Fulton has an interesting paper on the decrease in
the supply of fish, and the remedies for it, especially in relation
to sea-fish propagation and culture. In 1891 it was decided by
the Board that a sea-fish hatchery should be erected and
equipped at Dunbar, after the pattern of the hatchery of Captain
Dannevig at Flodevig, Arendal, Norway. Dr. Fulton went to
examine the arrangements at Flodevig, and the construction of
the establishment at Dunbar was commenced. The whole of
the expenditure has been met from the ordinary Government

28 MARKETABLE BRITISH MARINE FISHES CHAP.

grant to the Scotch Board for scientific investigations, but an
additional £1,500 is asked from the Treasury in order to
enclose creeks and convert them into sea-ponds.

The work performed by the staff of the Marine Biological
Association in 1890, 1891, and 1892, is recorded in the numbers of
the Journal published in those years. It includes a comprehensive
account of the reproduction and development of the conger,
which contains the results of experiments and observations made
by means of the aquarium and extending over two years. These
researches brought to light or confirmed several important and
remarkable facts concerning the history of this fish, which will
be found detailed in their proper place in the present work.
The value of the aquarium is also shown in the results obtained
in the experimental investigation of the growth of fishes,
especially of the flounder, a number of specimens of which were
kept alive for three years, their size and condition with respect
to sexual maturity being examined from time to time.

Another research of great interest was that of Mr. William
Bateson on the various modes in which different fishes seek their
food, and the possibility of inventing some cheap and effective
form of artificial bait for long liners.

It should be borne in mind, in comparing the work of this
Association with that of the Scottish Fishery Board, that its
total annual revenue has been from 41,000 to £2,000, and that
it has not been possible to devote more than half of this to
fishery investigations or to employ the services of more than one
investigator in such work until 1891, when by means of a special
donation from Mr. J. P. Thomasson of £250 the services of Mr. E.
W. L. Holt were also secured. This naturalist, who did such good
work in the Irish survey, was stationed at Grimsby, where the local
Marine Fisheries Society placed their small but useful establish-
ment at his disposal. His first work consisted in the careful
collection of evidence as to the size at which the most valuable
species of flat fish in the North Sea became mature. Evidence
as to the same question with regard to fish of the same species
at Plymouth was collected by myself, and the results in the two
districts differ,a fact which constitutes one of the chief diffi-
culties in framing restrictive legislation in reference to the capture
of undersized fish.

The possibility of establishing a fishery for anchovies engaged

MODERN INVESTIGATIONS OF THE SUBJECT 29

the attention of the Council of the Association, and by means of
small meshed nets obtained for their capture, and by collecting
anchovies taken in the nets of the pilchard fishermen, an inquiry
was carried on concerning the abundance and the migrations of
these fish in the neighbourhood of Plymouth. The facts ascer-
tained compared with what is known concerning the annual
occurrence of the fish in the Zuyder Zee and other inlets on the
coasts of Holland, strongly suggest a regular migration of
anchovies between the latter district and the English Channel.

In the Eleventh Report of the Scottish Fishery Board pub-
lished in 1893 it is stated that actual work at the Dunbar
hatchery had not commenced in 1892. Of the scientific in-
vestigations described perhaps the most striking are those of Dr.
Fulton on the movements and rate of growth of plaice and other
fishes in the Firth of Forth and St. Andrews Bay. The method
followed in this inquiry was to mark fish by attaching a
numbered label to each when captured, and then to set them free
again. The chief difficulty was to invent a mode of marking
which should be sufficiently permanent, and yet not interfere
with the health and growth of the fish. Dr. Fulton after many
trials obtained the most satisfactory results from using small
brass labels fastened by black silk cord round the root of the tail.
Of plaice the great majority marked were immature, and about
I in 10 were recaptured. An interesting result was obtained on
comparing the places of recapture with those where the fish were
liberated : the plaice were found to move in definite directions,
westwards on the south side of the Firth of Forth, eastwards on
the north side. Cod were found to move to much greater
distances than plaice. The information gained by the experi-
ments concerning the rate of growth though of some value, is
not perfectly satisfactory owing to the fact that the cord by
which the labels were attached caused injury to the tail and the
fish seemed usually to have suffered in health.

The Report contains further contributions by Professor
McIntosh to the knowledge of the life-histories of the food-
fishes, and various other papers on the rate of growth of fishes
and the zoology of the sea.

The Twelfth Report, published in 1894, contains the first
account of operations at the Dunbar hatchery, together with a
complete description of the establishment from the pen of Dr.

30 MARKETABLE BRITISH MARINE FISHES CHAP.

Dannevig, son of the Captain Dannevig, of Arendal, who has
made the practical hatching of sea-fish his special study for so
many years. Over twenty-seven million plaice eggs were
obtained from the spawners, and over twenty-six million fry
were obtained and “planted” in the sea. The arrangements of
the Dunbar hatchery are interesting, and the chief features are
as follows: There is a spawning pond forty and a half feet
long, eighteen to twenty-six and a half feet broad, eleven
feet deep. This is on a higher level than the hatching
house. Water is supplied to it by means of steam pumps,
and the overflow passes through a filtering chamber, where
the floating eggs are retained, and then down a_ shoot on
to a water-wheel, which works certain simple machinery for
agitating the hatching boxes. The pumps supply also water
from the sea to the hatching boxes, the water being filtered on its
way. The fish are placed in the spawning pond when nearly
ripe, and allowed to spawn of their own accord.

The remainder of the scientific part of the Twelfth Report,
although valuable and important, does not indicate any great
novelties in the operations of the Board. Prof. McIntosh and
his pupils and assistants describe as usual the results of various
studies of problems connected with the life histories of the more
valuable fishes in their natural condition in the sea, and these
indicate steady progress in the investigations carried on at the
St. Andrews Laboratory. Dr. Fulton gives a report of some
definite and precise experiments on the effect of the size of the
mesh of the trawl on the sizes of the fish captured. These
experiments were carried out by the Gar/and, and consisted in
fastening outside the trawl net, round its end, a net having
meshes of only halfan inch square. The fish which escaped through
the trawl were retained by the outer net, and the comparison of
those found in the trawl and outside it is very interesting.
Trawls with meshes of various sizes were tested in this way.

It will be seen from the above summary that the organisa-
tion of the scientific department of the Scottish Board in the
year 1894 consisted of (1) The Superintendent in Edinburgh and
the steamer Garland employed for special experimental inquiries
at sea, and for the examination of the closed and unclosed
trawling grounds ; (2) the hatchery at Dunbar under the control

I MODERN INVESTIGATIONS OF THE SUBJECT 31

of a special manager, but subject to the supervision of the
Superintendent ; (3) the laboratory at St. Andrews, where Pro-
fessor McIntosh and a succession of pupils and assistants from
the Universities of St. Andrews and Edinburgh carried on the
more purely zoological researches. Special investigations of the
physics of the sea, circulation of water, density, temperature, &c.,
were also carried on by experts not on the permanent staff of
the Board, on H.M.S. /ackal, commissioned to perform fishery
service.

During the years 1893 and 1894 Mr. Holt continued to work
in the service of the Marine Biological Association at Grimsby,
and the staff of the Laboratory at Plymouth. Much of the
work had reference to the question of the capture and destruc-
tion of immature fish, to which attention was still more strongly
drawn by the appointment in 1893 of a Select Committee of the
House of Commons to inquire into it. Mr. Holt’s Report in the
Journal gives extensive statistics of the number of immature and
mature fish of certain kinds brought to the Grimsby market.
At Plymouth I was largely occupied in studying microscopically
the development of the egg in the roes of fishes, and the con-
dition of the roe before and after spawning, in order to obtain a
more complete knowledge of the various conditions seen in
different individuals at different times of the year. I also spent
much time in the endeavour to overcome the difficulty of rearing
the delicate newly-hatched young of food-fishes in confinement.
It is generally admitted that the benefit effected by merely
hatching the eggs and then consigning the larve to the sea, is not
likely to be so great as that which might be secured by protect-
ing the young fish in their early and delicate stage. Various
papers on points connected with the natural history of fishes are
contained in the recent numbers of the Association’s Journal.

CHAE DER

THE CHARACTERISTICS OF VALUABLE MARINE FISHES AND
THE REGIONS IN WHICH THEY Live

THE word fish is often used to include nearly every creature
that lives in the sea. We talk of star-fishes and of shell-fish, as
well as of fishes in the stricter sense. The oyster and the
lobster are both called shell-fish, notwithstanding the great
difference between them in the matter of legs and claws. The
passive, transparent objects which we call jelly-fishes have no
resemblance to either a star-fish, oyster, lobster, or fish. Then
again the whale and the porpoise are often called fishes, and
supposed by many people to be quite correctly so called. But
in order to learn something about the history and origin of these
creatures and how they live, we must take the trouble to study
the differences between them. We must find out how many
principal kinds of animals there are in the sea, bringing together
those that are alike and separating those that are unlike. This
is the first step towards the recognition and identification of the
various kinds in all the stages and periods of their lives.
What is found to be true of one kind of animal or one kind of
fish may not be true, and in fact very often is not true, of another
kind. A correct knowledge of certain facts about the history of
some particular fish may be and often has been seriously mis-
understood, when the various kinds have not been properly
distinguished.

Now in the first place there is one grand difference among
animals in the construction of their bodies, namely, that some
possess a back-bone, and others do not. We ourselves have a
back-bone, and likewise beasts, birds, reptiles, frogs, and fishes.

cu. 1 CHARACTERISTICS OF VALUABLE MARINE FISHES

ww
Ww

Star-fishes, jelly-fishes, oysters, lobsters, and many other
creatures belong to the great tribes of lower animals which have
no back-bone. Back-boned animals never have more than two
pairs of limbs, corresponding to our arms and legs, while the
lower animals, as for instance insects, crabs, and lobsters, may
have a great number of legs.

Back-boned animals are better known to most people than
the lower animals. In fact with the exception of a few like the
oyster and lobster, which are eaten as delicacies, the lower
animals are usually regarded with more or less disgust. But
we all know enough about the back-boned animals to distinguish
between beasts, birds, reptiles,and fishes. We know that beasts
have hair, birds have feathers and wings, reptiles and fishes are
usually covered with scales. The scales of a reptile however are
fixed, and do not come off easily like those of fishes. But the
most important peculiarity of fishes is that they have gills which
are placed at the sides of slits or openings behind the head,
through which water passes from the throat to the outside of the
body. Nowa whale or a porpoise, although its body is shaped
much like that of a fish, has no gills and no scales. These
creatures are therefore not fishes, not of the same class of animals
as mackerel, herring, or shark. What then are they? Ex-
amination shows that they have some traces of hair on their
skins. They also breathe air by means of lungs just as we do.
Every one knows that a whale spouts or blows, which means
that it comes up to the surface of the water to breathe out the
air in its chest, and takes in a fresh breath before it dives again.
But this is not all. The whale and porpoise and other such
creatures bring forth their young alive and suckle them after-
wards, exactly in the same way as dogs or cats or other quad-
rupeds. They belong therefore to the tribe of beasts, although
they live entirely in the sea, and never, as seals do, emerge on
to the shore. They are beasts which have left their kindred and
taken to a sea-faring life.

The lower animals which inhabit the sea form five very
distinct great tribes, differing from one another in structure of
body and mode of life, as much as they differ from fishes.
The following well-known animals are representative examples
of these tribes: lobster, oyster, lug-worm, star-fish, and jelly-
fish. The lobster belongs to the tribe of Crustacea, sufficiently

D

34 MARKETABLE BRITISH MARINE FISHES CHAP.

distinguished by their hard jointed outer covering or shell, and
their numerous pairs of jointed legs. The oyster represents the
Molluscs, of which the principal sub-tribes are the bivalves having
two shells hinged together like the oyster and mussel, the
univalves like the periwinkle or whelk, and the cuttle-fishes and
squids which have no external shell and are active swimmers.
Of Worms there are myriads of different kinds. The creatures
of the star-fish tribe are called Echinoderms, or spiny-skinned
animals, and occur in three principal forms, the rayed form like
the star-fish, the globular form like the sea-urchin, and the
cylindrical form like the sea-cucumbers. The animals represented
by the jelly-fish also have the radiate or star-like structure,
presenting a number of similar parts arranged round a centre.
The tribe includes besides the floating jelly-fishes, the sea-
anemones, which are attached by a flat base to rocks, stones, and
shells, and the zoophytes, which are commonly supposed to be

Fic. 1.—The Smaller Spotted Dog-fish. D.F. dorsal fin; V.F. ventral fin; C.F.
caudal fin); Pe, Bs pectoral) fim; Pv. B. pelvic fins) GS. silleshits sp:
spiracle ; L.L. lateral line.

The outline figures in this chapter are based upon the illustrations of Day’s British
Fishes.

sea-weeds and which grow from a fixed base in a branching
plant-like form. In addition to all these there are the sponges
and the minute microscopic creatures which belong to the animal
kingdom and are simple particles of living substance which multi-
ply by self-division. The plants of the sea consist of the well-
known sea-weeds, and a vast multitude of different kinds of
minute green or brown particles which are suspended freely in
the water. For the purpose of the present work these various
tribes of creatures will only be mentioned in their relation to the
life of fishes, and a general survey of the characteristics of the
principal British marine fishes is now to be given.

Fishes then may be defined as aquatic animals which have

II CHARACTERISTICS OF VALUABLE MARINE FISHES

Ww
un

a backbone or some rudiment thereof, which breathe water by
means of openings from the throat behind the mouth, and which
usually possess paired and unpaired fins. The gills of fishes are in
most cases rows of delicate ridges or of projections on the sides of
the gill openings (G. S., Fig. 1.) ; the blood flows through these
ridges or projections, and is thus exposed to the influence of the
water which is constantly passed through the gill-openings from
the mouth. The fins are thin projecting folds of skin supported by
movable hard firm rods called fin-rays. The unpaired fins are
in the middle line between the two similar halves of the body,
there are some on the back called the dorsal fins, some on the
belly called the ventral fins, and one at the hinder end of the body,
namely, the tail-fin. ‘The paired fins are on the sides of the
body, and attached by a short base. There are never more than
two pairs, corresponding to our own arms and legs, or to the
forelegs and hindlegs of a quadruped. The fin-rays in fact
represent in a general way the toes or fingers of the limbs of the
higher animals, while in fishes the long limb projecting from
the body is not required, and is represented only by the bone or
cartilage at the base of the fin. The front pair of fins corre-
sponding to the arms of the human body are always placed close
behind the gills and may be called the breast-fins or pectoral fins
(Pc. F., Fig. 1.). The second pair are placed nearer to the lower
edge of the body, and in many fishes are situated in their original
position far back near the vent, as for instance in a dog-fish or
salmon, while in many others they are below or even in front of
the breast-fins, as for instance in the mackerel or cod. These
fins, whatever their position, may be called the pelvic fins (Pv. F.,
Fig. 1.), while they are sometimes called abdominal fins or throat
fins according to the part of the body in which they are situated.
The organs of sense with which we are familiar in higher
animals, namely, nose, eyes, and ears, occur in a well-developed
condition in most fishes, but with certain important differences
in structure. The nostrils as a rule have no posterior communi-
cation with the throat, but are merely pits opening on to the
surface of the skin. The ear consists only of the essential
apparatus of hearing, a closed cavity hidden in the side of the
skull, and not connected with structures externally visible.
In addition to these there is generally an additional sensory
apparatus which is very characteristic of fishes, and which
ID)

36 MARKETABLE BRITISH MARINE FISHES CHAP.

furnishes important marks for the recognition and classification
of species. This apparatus

5 2 consists usually of tubes in
N OS ° 5
3 aN iaika the skin opening by rows
w--- & ey
5 ou of pores on to the surface,
2) Q ais . .
te 2 and containing in their
ics ;
Ilo walls minute — structures
aim © ;
Ono . connected with the ends of
5 ee nerves. It is probable that
ois oo : .
S, abs the function of this appar-
= 3 oc fo} = PP
2 Sa atus is to enable the fish
=| o .
Pod & to perceive movements of
5 n
sep the water such as those
Oo bf
<~Eas caused by the passage of
Tey Os ¥ 5
a BOs another fish, but very little
3 $5) te
= ola is known with any certainty
N rae airs :
© § oS + on the subject. Whatever
Sue — ound :
= ssieeier 3 the function the general
nee arrangement of the tubes
oS [o) os Os 5
Ze 8 is very constant: there is
a? AB usually one down each side
dow
seco of the body from the gills
uO 2
ae oe to the tail, and the course
4am : : 3
ao. of this being visible ex-
Poe s 5
3252 ternally forms what is
or .~ .
me S called the /ateral line (L.L.,
ise] vo 3 -
Ee weak Fic. 12.) In) fromeptais
OF Sy f=)
egg tube divides into several
Q, o
Mo Ce branches on the head, but
ey Sh ea
bso these are not usually con-
tel” & leiae, :
= Bo 6 spicuous on the surface.
g <q o> = The class of fishes con-
S Secs :
“S {2 SSE ¢ sists of a number of very
Ss) sts Wie 3
8 es distinct orders which differ
s sos :
= S sae" very widely from one an-
o- a 5 .
= = a Ep ws other, and in some of which
v
Shes z many of the characters
Lea5 above described are want-
Niisicn cw
BU

ing. These characters in
fact are only found all

Fia.

II CHARACTERISTICS OF VALUABLE MARINE FISHES 37

together in the fishes of the higher orders, with which we are
most familiar, and which include the kinds to be chiefly con-
sidered in the present work. There are three orders which
are of no importance commercially in this country. One
of these may be called the lung-fishes, because although
they have gills and fins they are provided with primitive lungs,
corresponding to the air-bladder of other fishes, and with
these to a limited extent they breathe air. None of these
are European. Another order contains the lampreys and
the curious hag-fish or borer which is familiar enough to line
fishermen of the north-east coast of Britain. These have no
paired fins. Their mouth is suctorial, and their gill-passages
instead of being wide slits are in the form of pouches which
open on the sides of the neck by small holes or by tubes leading
to a single hole. A third order contains only a singular and
much simplified creature called the lancelet or Amphzoxus. The
structure of this creature is shown in Fig. 2. It has no side fins
no bones, no gristle, and properly speaking no head. It has no
eyes, hearing organs or smelling organs like those of other fishes,
but a single rudimentary eye and one simple nostril: it has no
distinct brain. But still it has two of the most essential organs
of a fish: a rudiment of a back-bone, and gill-slits. The former
is a rod of laminated tissue running from one end of the body to
the other, the latter are very numerous slits in the sides of the
gullet, but they open into a gill chamber which communicates
with the exterior by a single small aperture. The lancelet is
common enough on our southern shores. I[t is only two inches long,
is very transparent, and buries itself in the sand. We shall not need
to consider these three orders any further in the present work.
Among the fishes which have a commerical value are
members of two very distinct orders, dog-fishes and skates or
rays on the one hand, and scaly fishes, such as the herring,
the plaice, and the cod on the other. In the first order the
skeleton contains no true bone, but consists of cartilage, or
gristle which is soft and elastic. The skin is furnished not with
scales, but with bony spines, plates, or tubercles which contain
lime, and are in consequence hard and strong. The arrange-
ment of the gills is very different from that seen in scaly fishes.
There is no gill-cover, but five separate gill-slits open on the
surface of the skin in the neck region, and can be seen to

38 MARKETABLE BRITISH MARINE FISHES ee)

expand and contract regularly while the fish is alive. There is
also usually a smaller opening from the throat, known as the
spiracle, and situated just behind the eye. Another peculiarity
of these fishes is the position of the mouth, which is a wide
transverse slit on the flat, lower surface of the head. In other
words, the snout projects usually to some distance beyond the
jaws and terminates in a point. The fin-rays in these fishes are
rods of gristle or cartilage with very numerous joints, and in
addition to these there is beneath the skin of the fins a layer
of fine horny fibres. The second pair of side fins or pelvic fins
are always placed close to the vent. The tail has a characteristic
form, consisting of two unequal lobes, of which the upper is the
longer: the spinal column is bent up at the base of the tail, and
continued into the upper lobe.

Fic. 3.—The Bass, as example of the bony fishes. D.F. dorsal fin; V.F. ventral
fn; C.F. caudal fin; Pe. F. pectoral fin; Pv. F. pelvic fin; L.L. lateral
line ; G.C. gill-cover ; N. nostrils of right side.

Bones and scales are the chief characteristics of the scaly
fishes, although in some the scales are almost or entirely absent,
as for instance in the eel. The scales overlap one another like
the tiles of a house, and the larger part of each is imbedded in
the skin, only the smaller hinder portion being exposed. The
tube of the lateral line pierces a longitudinal series of special
scales, and to each of these scales corresponds a pore open-
ing into the interior of the tube. The mouth is usually at the
end of the snout and provided with bony jaws and teeth. The
gill-cover, a broad plate on each side behind the head supported
by bone, covers over the chamber in which the gills are contained

II CHARACTERISTICS OF VALUABLE MARINE FISHES 39

and ends in a free edge behind. In the gill-cavity are the gills,
which are four double fringes of red processes attached to four
slender columns consisting chiefly of bone. These columns form
part of the sides of the throat, and they are separated from one
another by five slits, through which the water passes from the
throat over the gills into the gill-chamber, and then out at the
gill-opening. The slits correspond to those of the dog-fish, and
the columns supporting the gills to the partitions between the
slits in the dog-fish.

Between the gristly fishes, namely sharks and rays, and the
familiar bony fishes there is a tribe of fishes which have some
of the characters of both. They form all together a wonderful
Series of steps from the structure of one set to that of the other,
but are on the whole nearest in characters to the first division of
the true bony fishes, that is to such fishes as salmon or herring.
The only one to be mentioned here is the sturgeon. This fish
has a gill-chamber and gill-cover like a bony fish, but it has not
scales of the ordinary kind. In their place the skin is provided
with large plates of true bone in shape like large scales, but
much thicker. These form a row along the ridge of the back,
and two rows along each side. The fin-rays are all of the soft
kind, that is to say, composed of numerous joints and therefore
flexible, except the first of the breast-fin which is thick and rigid.
The second pair of side fins are far back. There is one dorsal
fin, quite short and small, placed behind those just mentioned.
The tail, like that of a dog-fish, has a long upper lobe, into which
the back-bone is continued. ‘The snout is much produced, and
rather broad and flat: underneath it in front of the mouth are
four slender fleshy barbels. The mouth is rather small and
round, and the jaws are capable of being protruded consider-
ably. The sturgeon grows sometimes to eighteen feet in length,
and is frequently taken in the North Sea, or at the mouths of our
large rivers. It occurs in greater numbers in the river Volga,
and is found also on the east coast of America. Several other
species of sturgeon are known, and they all spawn in large rivers
and descend to the sea only for atime in winter.

Among the creatures which we distinguish in the first place
generally as fishes, and which resemble one another, and differ
from other animals in the characters which have been mentioned
above, there are, as every one knows,a multitude of different kinds,

40 MARKETABLE BRITISH MARINE FISHES CHAP.

the individuals of which do not require further distinction. It
is not necessary or possible to pay much attention to the trifling
details in which one herring differs from another, or one
mackerel from another, or one skate from another. It is
sufficient to speak of so many mackerel or so many
skate, or of a mackerel or skate of such a weight and
such a size. We know that as an almost invariable rule
fishes, like other animals, exist in these distinct kinds which
are always recognisable, and capable of being distinguished from
one another. In each of the divisions which have already been
defined there are a great number of these distinct kinds or
species. But within each division again there are subordinate
croups of species, and in following out the history of the various
species it is necessary to have some acquaintance with these
further and subordinate groups. The species in fact are not
separated from one another by differences of equal degree, but
form natural families, each of which includes a number of species
distinct enough from one another, but having a family resem-
blance. Thus the pilchard, herring, and sprat are much more
like one another than they are to the species of another family,
such as the cod, haddock, and whiting. Again, even within the
family all the species are not equally different from one another,
but form still smaller natural groups, which the naturalist calls
genera. For example, the cod, haddock, and ling all belong to
one family, which we may speak of as the cod family, but
the cod and haddock are more similar to one another than
either is to the ling. Similarly, the herring and pilchard are
more like one another than either is to the anchovy, but all three
are placed in one family, called the herring family.

We have now to take a survey of the principal kinds of fish
in the divisions which have been defined above, and to notice
the chief peculiarities by which they are distinguished from one
another.

Our common dog-fishes on the one hand, and skates and
rays on the other, represent the two distinct types which are
found in the gristly or cartilaginous fishes. Dog-fishes and
sharks all belong to one great type or division, the term dog-
fishes being applied merely to the smaller and commoner kinds.
A great many kinds occur on our coasts, but none of them are
of any considerable commercial value, although some are in

———E———

II CHARACTERISTICS OF VALUABLE MARINE FISHES 4I

certain districts eaten as food or salted for use as bait. One of
the commonest is the spiny dog-fish, often called the spur-dog,
or picked dog-fish (Fig. 4). It has a strong sharp spine in front
of each of the two dorsal fins, and has no ventral fin. It isa
strong active swimmer which roams about in shoals pursuing and
preying upon smaller bony fishes such as herring and _ pilchard.
It is often very troublesome to drift-net fishermen on account
of the damage it does to their nets. The Greenland shark,
which has been frequently taken off our more northern coasts,
resembles the spur-dog in having no ventral fin, but it has no
spines connected with the dorsal fins. Its usual length is from
eleven to fourteen feet. The spotted dog-fishes are very com-
mon, and as they live on and near the bottom are usually taken
in the trawl. There are two kinds, the larger with large spots,
the smaller with more numerous small spots. In these species

ae UN

i

Fic. 4.—-The Spiny Dog-fish, or Spur-dog.

the two dorsal fins are placed far back and rather close together,
the ventral fin being opposite to the interval between them.
The teeth are small, numerous, and pointed.

Two other common dog-fishes are the tope and the smooth-
hound. They belong to the same family, in the members of
which the dorsal fins are far apart, and the ventral is opposite
the second dorsal. In the tope the teeth are large and sharp,
in the smooth-hound they are small and flat or pavement-like.
Both are often taken in the trawl, and reach a length of four or
five feet. The blue shark is a long slender fish, similar to the
dog-fishes just mentioned. It is said to grow to twenty-five
feet in length, but only young specimens six or eight feet long
are usually taken in British waters. These are not uncommonly
caught in drift-nets off the Cornish coasts.

The porbeagle, the thrasher or fox-shark, and the basking
shark, are three kinds of large but comparatively inoffensive

42 MARKETABLE BRITISH MARINE FISHES CHAP.

sharks which occur frequently in British waters. With respect
to their bodily peculiarities they all belong to one family,
having a stout thick form with the second dorsal fin and the
ventral fin of small size and opposite to one another. The
porbeagle, which is frequently taken in summer by the Cornish
fishermen, has long pointed teeth, and a keel on each side of its
tail. Its length is from three to eight feet. The thrasher is
conspicuously distinguished by the extraordinary length of the
upper lobe of the tail, which is as long as the rest of the body.
This tail is said to be used for beating whales, but it is certain
that this shark feeds upon herrings, mackerel, and other
gregarious fishes, and it seems probable that it swims round a
shoal of these fishes and lashes about with its tail in order to
keep them crowded together and prevent them from escaping.
The basking shark is of very large size, reaching twenty-five to
thirty feet in length. Its snout ends in a peculiar cylindrical
projection. Its teeth are small and conical, and it has numerous
long projections on its gill-bars which form a straining apparatus.
These projections are called gill-rakers, and resemble those of
the herring and other bony fishes, serving, as in these fishes, to
strain from the water that is passed through the gill openings
the multitudes of minute crustacea and other creatures which it
contains. This large shark therefore, like the huge whale and
the small herring, is nourished entirely by extremely minute
forms of life. It visits the west coast of Ireland annually in
considerable numbers, and is regularly hunted for the sake of
the oil obtained from its liver. It has the habit of lying motion-
less at the surface of the sea, and as it is not easily alarmed the
fishermen approach it in a boat and harpoon it. The fishery is
chiefly practised off the Achill and Boffin Islands.

The peculiar form of skates and rays as compared with dog-
fishes is connected with their habit of resting continually and
concealing themselves on sandy or gravelly ground. In this
respect they differ from dog-fishes as flat-fishes such as plaice
and turbot differ from round fishes such as cod or haddock.
But the mode of flattening in the two cases is as different as it
possibly could be, the difference being that the lower surface in
the skate is the belly, in the flat-fish the left or right side.
Accordingly, if the skate is divided down the middle line of the
upper surface the two halves will be exactly similar, whereas if

ll CHARACTERISTICS OF VALUABLE MARINE FISHES 43

the same thing is done to the plaice or turbot the one half will
be the back of the fish and contain the brain, the other will be
the belly half and contain the gills and intestines. The great
breadth of the skates and rays is due to the enormous size of the
breast fins, which extend from the hinder fins nearly to the tip
of the snout, passing above the gill-openings, and it is from this
cause that the gill-openings are on the lower surface of the fish.
The tail is correspondingly reduced, forming a whip-like ap-
pendage on which the two small dorsal fins are placed.

Skates and rays are coast fishes, not occurring at depths
beyond 500 fathoms, and they occur in greater or less abundance
in all parts of the world: in the large rivers of tropical regions
many kinds live entirely in fresh water.

The monk-fish or angel-fish, which is not uncommon in the
English Channel and North Sea, although usually classed in the
dog-fish division, shows us as it were the skate in process of
manufacture. The body is flat, the breast fins large, and the
fish rests on the ground, but the breast fins do not extend forwards
to the head and do not entirely cover the gill-slits above; the
hinder fins are not very much smaller than the breast fins, and
there is no sudden decrease of size between the body and tail.

Of skates and rays there are several families, the principal
being the electric rays, the common skates and rays, and two
families of sting-rays. All these are represented in British
waters. One kind of electric ray or torpedo reaching four feet
in length is often taken in trawls on the south coast and in
the North Sea. In the electric rays the front edge of the body
is quite straight. In the sting-rays, commoner off the south
coast than elsewhere, there are no fins on the tail, which is long
and cord-like, but a strong spine with toothed edges projects
from its dorsal side not far from the base.

The commoner rays, which are largely used as food, consist
of several kinds in two groups, the long-snouted kinds and the
short-snouted. The former are always distinguished as skates
by fishermen, the latter as rays or roker. The common
skate (Fig. 5) is distinguished by having a smooth skin and
having the lower surface coloured a bluish-grey nearly all
over. The flapper skate is rough on the back, and white
beneath; the white skate and the long-nosed skate are two
other large and common species. Of the rays the commonest

44 MARKETABLE BRITISH MARINE FISHES CHAP.

is the thornback (Fig. 6), which has spines of various sizes all
over its skin: in the starry ray the spines are all large and of
nearly the same size; the cuckoo ray has a circular black
mark with yellow lines in its centre, on each wing. Other
species are also distinguished by similar small differences.
Among the bony fishes one division or order is characterised
by the following peculiarities: the air-bladder when present,
instead of being completely closed and separate from other
cavities in the body, is connected by an opening or open tube

Fic. 5.—The Common Skate, lower or ventral surface.

with the interior of the gullet or stomach; the pelvic fins are
either absent, as in eels, or are in their original position in the
hinder part of the body, as for example in.the salmon ; thirdly,
the fin-rays are soft and branched, that is to say each ray is
composed lengthwise of a series of short pieces of bone united
by flexible gristle or cartilage, and also divides towards its outer
end into a number of separate smaller branches lying not in a
tuft like a brush, but side by side like the ribs of a fan. In
certain species however the first ray of the dorsal and ventral
fins and of the breast-fins forms a strong undivided spine.

. =

—

a es eee

Tere Ai the ee fe

a

II CHARACTERISTICS OF VALUABLE MARINE FISHES 45

A great many of the fishes belonging to this division are
inhabitants of fresh water, and our commonest fresh-water fishes
belong to one family, the carp family. Many of the species pass
certain periods of their lives in fresh water, and at other periods
live in the sea. Some of these, like the salmon, ascend rivers in
order to spawn, and descend after spawning: these are said to be
anadromous, or ascending. Others, like the eel, live in rivers or
ponds all their lives except when about to spawn, and then
migrate to the sea: these are said to be katadromous, or

\
SS
=~
Sus ay :
—) . 0) OR SY M6 OOe Cee ee CEO oo ee oe eet a
Retetaetat = ':
=
Zz
ZY 4
eo Ae aed
“fe &

Fic. 6.—The Thornback, dorsal surface.

descending. Excluding the species which belong entirely to
fresh water, there are only four families in British waters which
are of any commercial importance, namely, the herring family,
the salmon family, the eel family, and the gar-fish family.

The fishes of the herring family (Fig. 7) have a single dorsal
fin of no great extent, situated near the middle of the back, and
a single ventral fin near the tail. The tail-fin is deeply forked.
It is a remarkable peculiarity in these fishes that the lateral line
is absent. The body is rather narrow from side to side, and the
lower edge is usually sharp and toothed like a saw. This family

46 MARKETABLE BRITISH MARINE FISHES CHAP.

includes the herring, sprat, pilchard, shads, and the anchovy.
The herring and sprat regularly enter estuaries, while the shads
ascend to the upper waters of rivers and there spawn. The
pilchard, on the other hand, is more completely marine. The
herring is a northern fish, and does not occur in the Mediter-
ranean, but is abundant on the American side of the Atlantic.

Fic. 7.—The Herring.

On the American coast there are also other abundant and
valuable species of the herring family, namely the menhaden or
moss-banker, which is much larger than the herring, and is valued
chiefly for the oil which it yields and for use as bait, and the
mattowocca, which ascends into fresh water in spring and spawns
in ponds and lakes. The British shads are absent on the

Fic. 8.—The Smelt.

American side, their place being taken by the American shad, a
different species which is a much-valued article of food. The
pilchard extends from the Mediterranean to the south-west coast
of England, but not to the west side of the Atlantic. The
anchovy is also a Mediterranean fish, but not American.

The fishes of the salmon family (Fig. 8) are distinguished
by the possession of a rudimentary second dorsal fin: this fin,

II CHARACTERISTICS OF VALUABLE MARINE FISHES 47

which is placed in the hinder part of the body, is small and
destitute of fin-rays, consisting therefore only of skin and flesh.
The tail-fin is less forked than in the herring family ; the lateral
line and scales are well developed. The family includes fresh-
water species, marine species, and species which like the salmon
pass regularly from river to sea and sea to river. The fresh-water
forms are the trout, the grayling, and the various kinds of char,
Many kinds of sea trout have been distinguished in different
parts of the British Islands, but in the opinion of the late Dr.
Francis Day they are connected by intermediate forms with one
_ another and with the fresh-water trout, and so constitute with the

Fic. 9.—The Conger. Fic. 10.—The Common Eel.

latter one variable species. The smelt (Fig. 8) is found only in
estuaries or near the mouths of rivers, and spawns in brackish
water. It is distinguished by its somewhat transparent skin, which
is bluish on the back, with a bright silvery band along each side.
There are a few species of the salmon family which are entirely
marine and live at considerable or even extreme depths in the sea
or ocean. One of these marine forms, namely the argentine, is
British, having been frequently taken off the west coast of Ireland
and Scotland. It is distinguished by the smallness of its mouth,
absence of teeth, and the shape of the body, which consists of
flat surfaces bounded by longitudinal ridges. The argentine is
of no commercial importance in this country.

48 MARKETABLE BRITISH MARINE FISHES CHAP.

The eel-like fishes (Figs. 9, 10) are distinguished by their well-
known cylindrical, elongated form, by the entire absence of the
pelvic fins, and by the continuous dorsal and ventral fins, which
are not separated from the tail-fin. The scales are either
entirely wanting, or small and completely buried in the skin as
in the common eel. The latter and the conger are the only two
British species. The eel is taken principally in fresh water, but
it is known to migrate to the sea before spawning. The conger
lives entirely in the sea: it is easily distinguished from the eel
by its much larger eyes and jaws, and by the fact that its dorsal
fin commences at a point much nearer the head than in the eel.

Fic. 11.—The Gar-pike, Guard-fish, or Long Nose.

Fic. 12.—The Saury-pike, or Skipper.

In the gar-pike family (Figs. 11, 12) there is but one dorsal fin,
which consists of a rather small number of rays, and is placed
opposite the ventral in the hinder part of the body near the
tail. The air-bladder has no opening. In the gar-pike or
euard-fish, and in the saury-pike, the jaws are elongated into a
slender beak, the lower jaw being the longer. The saury-pike
or skipper is distinguished by the presence of several small
finlets behind both the dorsal and ventral fins. In both the
body is slender and long. These fishes swim actively in shoals,
and belong to the surface waters of the open ocean. They

II CHARACTERISTICS OF VALUABLE MARINE FISHES 49

often occur off our coast in abundance in summer and autumn,
and are taken in the mackerel nets: the gar-fish is much the
commoner. The flying-fishes of the tropical parts of the ocean
are placed in the same family, but in them the body is shorter
and the jaws are not elongated. Their pectoral fins are greatly
enlarged.

The next division of bony fishes is distinguished by the fact
that the air-bladder is closed, the second pair of side fins is
placed either just below or in front of the breast fins, and that
all the fin-rays are jointed and flexible, or soft. They are pre-
eminently the spineless fishes. The absence of spiny fin-rays
is also associated with the almost entire absence of large spines
on the body or head. The scales, however, are often well
developed and furnished with a spiny border. This order is
formed principally by the two great families of the cod-like
fishes and the flat-fishes, by far the most important ground
fishes, from a commercial point of view, in existence.

In the cod family (Fig. 13), there are in some cases three

Fic. 13.—The Cod.

fins on the back and two behind the vent, in other species two on
the back, the front one being short and the hinder long, and a long
ventral, in other species again a single long dorsal and a single
long ventral. The scales are small, without spines, and easily
detached. There is in many kinds a barbel on the chin. These
fishes belong chiefly to arctic and temperate coasts, a few species
living in the ocean abysses. The more valuable British species
are the cod, haddock, whiting, coalfish, pollack, bib or whiting
pout, ling, hake, and tusk or torsk. The family of sand-eels is
not very different in characters, but the fishes are much smaller :
E

50 MARKETABLE BRITISH MARINE FISHES CHAP.

they have the throat fins rudimentary or absent, and a single —
long dorsal and ventral. They burrow in the sand near shore.
They occur on the coasts of Europe and America, and there
are two British kinds, the larger sand-cel and the smaller.

The flat-fishes (Fig. 14) are the most remarkable of all
fishes in structure, because the surface on which they lie on the

Fic. 14.—The Plaice.

ground is one side of the body, either the right or the left
according to the species, and both eyes are on the upper side:
the upper side also is coloured, the lower side white and without
pigment. There is a long dorsal and long ventral extending
nearly from head to tail. No flat-fishes are found in the great
depths of oceans, but they are abundant in the tropics, and
along all coasts except those of the extreme north and south.
The tropical kinds are different from those of temperate regions,
and are for the most part useless as food. The principal
species in British waters are the plaice, flounder, dab, witch,
lemon dab (called usually lemon sole), halibut, long rough dab,
sole, turbot, brill, and megrim.

The third great division of the bony fishes has, like the
second, a closed air-bladder and the pelvic fins in the front part of
the body, but many of the fin rays form strong stiff spines, and
spines are often largely developed on the head and body. This
division contains a great variety of forms, classed by naturalists.

II CHARACTERISTICS OF VALUABLE MARINE FISHES 51

in a large number of families. The well-known fresh-water
perch and a number of species resembling it form one family.
In the perch and others there are two fins on the back, the front
one being supported entirely by spines. In all fishes of this
division when there are separate fins on the back the first
always contains spiny rays only, while most of the rays in the
rest are jointed and soft. Inthe perch-like fishes there are no
scales over the longitudinal fins, no barbels, and the teeth are
small and pointed. There are a great number of different kinds
of fishes in the family, some of which live in fresh water and
others in the sea. The latter are all coast fishes, and occur all
over the world in temperate regions and the tropics. The only
marine species of any great importance in Britain is the bass
(Fig. 3), sometimes called salmon-bass on account of its
elongated shape and bright silvery skin. It has no close re-
lationship with the salmon, as is at once evident from its spiny
first dorsal fin and the situation of its second pair of side fins
beneath the breast fins.

The sea breams (Fig. 15) resemble many species of the perch

Fic. 15.—The Common Sea Bream.

family in the character and arrangement of their fins, but are

distinguished by their peculiar teeth, of which those in front have

broad cutting edges and those behind round tops formed for

crushing. They are all coast fishes, and many different kinds

occur more or less commonly on the more southern shores of
Ey Z

52 MARKETABLE BRITISH MARINE FISHES CHAP.

the British Isles, but only one, the common sea bream, is of
much importance in the market. They are bottom-feeding

fishes, good, but not very rapid, swimmers.
The red mullet are well-known fishes, having always

Fic. 16.—The Striped Red Mullet.

possessed a high reputation as delicacies for the table. They
are distinguished by their red colour, the sloping front of the
head, and the two stiff barbels attached to the chin (Fig. 16).
They are bottom-feeders, and swim in shoals making long
migrations. All the species of the family are marine, and none
occur either at the surface or the bottom in mid-ocean. They
belong to southern regions, and our red mullet only occurs
abundantly on our more southern shores. The family of horse
mackerels (Fig. 17) are chiefly distinguished by the great length

SS W N

SS teat
eC

Fic. 17.—The Common Scad, or Horse Mackerel.

of the second dorsal fin, and the reduction of the first, which is
in many quite rudimentary. They are for the most part oceanic

II CHARACTERISTICS OF VALUABLE MARINE FISHES 53

fishes, and have their headquarters in the tropics. The well-
known pilot-fish, celebrated as the companion and guide of the
shark, belongs to this family, as also the common scad or
horse mackerel.

The John dory (Fig. 18) and the boar-fish are the British
members of a small family represented on the coasts of tempe-
rate regions. They have a thin, deep, short body, with a long
first dorsal fin, and narrow second dorsal and ventral. The

Fic. 18.—The John dory.

mouth is curiously constructed, so that when opened it is auto-
matically protruded and formsatube of some length. They are
very slow swimmers, accustomed to hover in the water, and
swim both near the bottom and in mid-water: but the dory is
chiefly taken by the trawl.

The mackerel family (Fig. 19) are much more like the horse
mackerel than are the dory and boar-fish. They are active,
powerful swimmers, and many of the species are large fish living
in the open ocean: the latter are the tunnies. These fishes
usually have two dorsal fins, and behind the second dorsal and

54 MARKETABLE BRITISH MARINE FISHES CHAP.

ventral are a number of small finlets. The scales are small and
in the tunnies are limited to certain regions on the breast, form-

WOO
s+ \
Poe

SS TEELEEACS LEE Sey
EE we \ Ne
Z Mig —— a
Sig <

I

Fic, 19.—The Mackerel.

ing a kind of corselet or breast-plate. They swim in shoals
near the surface.

The angler or fishing frog (Fig. 20), sometimes called the
monk-fish, belongs to a curious family of fishes in which the tail
is much reduced, the mouth proportionately large, and the side
fins formed for walking on the bottom or holding on to sea-weed.
The angler lives on sandy or gravelly ground. The weevers are

Fic. 20.—The Angler, Fishing Frog, or Monk-fish.

fishes of no value as food, which have their eyes on the top of the
head and bury themselves in sand in an upright position. The
bull heads or hard heads and the gurnards are usually placed in

I CHARACTERISTICS OF VALUABLE MARINE FISHES 55
one family. They are bottom fishes. There are two dorsal fins,
and long spines projecting from the bones of the gill-cover. In
the bull heads, one of which is the common fresh-water miller’s
thumb, the skin is without scales and soft. The gurnards (Fig.

<
.
x S
Ko
<<
.
>< \
S —
= : —— QQ im S = ATTA | Sak
= ys eS —
= z SS COC OOCEEE EEE EEE ace NS A
: - . \
SS ERR =
W =

Fic, 21.—The Common or Grey Gurnard.

21) are distinguished by their three fingers or legs on each side
of the body, and the bony covering of the head. In the sucker
fishes and gobies the throat fins are formed into a sucker, which
in the latter shows the original structure of the fins less altered

Fic. 22.—The Lump-sucker,

than in the former, where the sucker is level with the skin.
These are all small shore fishes, except the lump-sucker (Fig. 22),
which is of no importance as a food fish. The dragonet, the
male of which (Fig. 23) is remarkable for its beautiful colouring

56 MARKETABLE BRITISH MARINE FISHES CHAP.

of orange and blue, is allied to the gobies. There is another
family of small sucker fishes, in which the sucker is not formed
from the ventral fins, but lies between them ; they have a single
dorsal fin without spines.

The blennies are shore fishes, mostly of small size, distin-
cuished by their usually scaleless skin, and long dorsal and

J

Fic. 23.—The Dragonet, male.

ventral fins ; the body is long and the head blunt. The cat-fish
(Fig. 24) is a gigantic blenny of northern seas living in deeper
water.

Two other families it is necessary to mention are the atherines
and grey mullets (Fig. 25), which are somewhat similar to one
another. They are remarkable for having the second pair of

Fic. 24.—The Cat-fish.

side fins somewhat behind the breast fins. There are two dorsal
fins, both short. The teeth are feeble in the atherines, absent in
the grey mullets. The atherine or sand-smelt of the south shores
of England resembles the true smelt in appearance and habits,
and has a bright silvery band down the side.

In the stickleback family also the second pair of side fins

Il CHARACTERISTICS OF VALUABLE MARINE FISHES Bi

are behind the breast fins, and the first dorsal is only represented
by separate spines: there are no scales but bony plates. Only

Fic. 25.—The Thick-lipped Grey Mullet.

one species lives in the sea, namely the fifteen-spined stickle-
back (Fig. 26).

TEE EEE KK EEE SLE 3

Fic. 26.—The Fifteen-spined or Sea Stickleback.

The wrasses are distinguished by possessing an extended
dorsal fin the greater part of which is spinous, by having strong

Fic. 27.—The Common or Ballan Wrasse.

crushing teeth in the throat, and thick fleshy lips over the jaws
(Fig. 27). They are shore fishes which live in the neighbourhood

58 MARKETABLE BRITISH MARINE FISHES CHAP.

of weed-covered rocks, and, in the tropical seas, of coral reefs.
Most of them are gaudily or beautifully coloured, and though
eatable are of no commercial importance in our country.

The pipe-fishes (Fig. 28) belong to another, that is a fourth,
great division of the bony fishes, differing from the others in the
structure of the gills and in many other respects. There are no

> SSS = tale Goa
oer ar. -¢ 4 RA os
A SEE

== = TEeaacaas =

—

Fic, 28.—The Common Pipe-fish.

spiny fin-rays, a single thin soft dorsal fin, no second pair of side
fins, and the tail fin much reduced or absent. The jaws are
elongated into a tube with a small mouth at the end of it.
These fishes live amongst sea-weeds, where by their swaying
slow movements and similar colouring they are almost completely
concealed. The sea-horse is one of them, and it is occasionally
but rarely found on British or Irish coasts, but is common in the
Channel Islands.

If we consider the different habits of the fishes just passed in
review, and the various modes by which they are captured, we
find the principal division is into bottom fishes and surface fishes ;
the bottom fishes can be again divided into hook fishes and trawl
fishes, according to the instrument with which they are usually
captured, but the division is not complete, many kinds being
caught in both ways. The bottom fishes which are important in
connection with national food supplies, are those which live in
shallow or moderately deep water. The limit of profitable
fishing is seldom much beyond two hundred fathoms, at which
the deep sea region may be considered to commence, and the
limit of beam trawling is much less than this and may be put at
eighty fathoms. For commercial purposes therefore the fishes

11 CHARACTERISTICS OF VALUABLE MARINE FISHES 59

of the deep sea are of no value. With respect to abundance of
supply and usefulness and palatability as part of a regular diet
two families of bottom fishes surpass all the rest : these are the
cod family and the flat-fish family. These families are developed
more in the north temperate region than in any other part of
the world. Moreover there is no region in the world in which
within the north temperate region there is such a vast extent of
fishing grounds less than eighty fathoms in depth, or less than
two hundred fathoms, as in the neighbourhood of the British
Islands. It may be safely said that there is no place in the
world from which such a valuable and constant supply of fresh
sea-fish is brought to market as from the North Sea. On the
east coast of America the suitable ground is so limited, and the
produce of such fishing of so little value, that the beam-trawl
is not used at all, the name trawl being applied by American
fishermen to the long-line. On that coast neither the sole nor
the turbot are found, and the other flat-fishes representing plaice
and lemon-soles are not equal to these in value.

In the beam-trawl fishery of Britain the principal products
are haddock, plaice, soles, turbot, and brill, although a good many
cod, hake, and ling are caught ; whiting also are of some im-
portance. Other families which contribute to the produce are
skates and rays, gurnards, sea breams, and red mullet, also the
angler and cat-fish, and to a certain extent the conger. In the
line fishing the larger fish and those living in rather deeper water
are taken, namely cod, ling, halibut, turbot, and brill, but plaice
and soles to an insignificant extent ; skate are also taken.

Of the surface fishes caught in drift-net and seine the great
majority belong to the herring family, namely, herrings, pilchards,
and sprats. The gar-fish and saury-pike are of no great im-
portance, being taken only occasionally for a brief season, and not
affording a large or continued supply. The mackerel, belonging
to quite a different order of fishes, is the only other species of
surface fish of great commercial importance.

We may next consider the particular geographical limits of
the more important species within the seas surrounding the
British Islands. These seas may be said to form an area of
transition between the home of the southern or Mediterranean
species and that of the northern or Arctic forms. Thus the
plaice, cod, and herring are more numerous and of finer quality

60 MARKETABLE BRITISH MARINE FISHES CHAP.

in the more northern parts of our seas; the sole, pilchard, John
dory, conger, and various others are characteristic of the southern
coasts of Britain and Ireland. Soles are scarce north of a line
drawn from St. Abb’s Head to the northern extremity of Den-
mark. Halibut are scarce even in the northern part of the
North Sea, and only become plentiful as the Far6e Islands are
approached. Turbot and brill are southern forms like the sole,
but extend somewhat further to the north. Speaking generally,
the majority of the cod family belong to the north, the hake
being the most southern, while of flat-fishes the forms most
similar to the plaice and halibut are northern, the rest southern.
On the south coasts families such as the: mullets,. breams,
and gurnards are abundant, which are scarce or absent in
the north.

The various kinds differ also considerably in the depth of
water and distance from shore at which they live, and the depth
of water seems to be by far the more important of these two
conditions in separating the territories or ranges of different
fishes. Among the flat-fishes the species which lives nearest to
the land is the flounder, which is found chiefly in estuaries and
the lower parts of rivers, often ascending to fresh water, and only
going to sea to spawn, where it is not found beyond a depth of
thirty fathoms. Plaice is next in attachment to the shore, being
seldom taken on grounds more than forty fathoms deep, and most
abundant at from five fathoms to thirty; it enters estuaries
also, but does not ascend so high as the flounder. The common
dab becomes rare beyond thirty-five fathoms, and like the plaice
is abundant in shallow water and in estuaries. The sole, like the
plaice, is often fairly abundant in shallow water, and enters
estuaries ; it is not found plentifully beyond forty fathoms. The
lemon dab has much the same limits as the sole, but is not so
common in shallow water near shore. The brill and turbot have
about the same limits as the sole, and are often taken in quite
shallow water, though seldom entering estuaries. The long rough
dab occurs at from twenty to fifty fathoms, and the megrim and
witch are deep-water species extending from twenty or thirty
fathoms to three hundred fathoms and seven hundred fathoms
respectively.

Among round fishes cod and haddock range from ten fathoms
to one hundred or one hundred and fifty, but adult whiting are

II CHARACTERISTICS OF VALUABLE MARINE FISHES 61

seldom taken in less than ten or more than forty fathoms. Ling
belong to deep water, ranging from ten to one hundred and fifty
fathoms or more. Pollack haunt the neighbourhood of weed-
covered rocks ; coal-fish range from five to seventy fathoms or
more. Gurnard extend from five to eighty fathoms, and the
John dory from five to forty.

CLAP aE eth)
THE GENERATION OF FISHES AND THEIR FECUNDITY

THE generative organs of fishes differ considerably in different
classes and orders. In skates and dog-fishes (Fig. 29) they
resemble closely those of birds. In the female the ovary, or organ
where the eggs are produced, is a lobed mass at each side of the
body cavity, and attached to the dorsal wall of that cavity. The
eggs when mature are very large, and in adult specimens a
number of them of various sizes and stages of development are
seen bulging out from the surface of the ovary. These eggs when
ripe burst through the surface and become free. They are round
balls of yellow yolk, of considerable:size, larger in some species
than in others, but not very much larger or smaller than the yolk
of a hen’s egg. Running along the back of the abdominal
cavity is a fleshy tube, the egg-tube or oviduct. This tube is
open at both ends. Inside the body its open front end is situated
at the side of the gullet in front of the liver. Its hinder end
leads into a sac which opens to the exterior at the vent. The
eggs must get into this tube, and pass down it, before they can
escape from the fish. They are taken up into the opening at its
front end, swallowed as it were by the egg-tube, and pressed down
it by the movement of its sides. Towards the upper part of this
tube is a ring-like thickening, and here the tough horny shell is
formed. The upper end of the oviduct usually contains some of
the milt of the male, introduced during the union of the sexes,
which takes place from time to time as in higher animals. By
the action of this milt the germ in the yolk is fertilised. At the
same time a certain quantity of clear sticky liquid, the “ white,” is

ee —eEEEEEeEeEeEeEeEeEEEEOeeeeE—eE—eE—eEeEeEee—eEeEEEE~ rere

cHap. 11 GENERATION OF FISHES AND THEIR FECUNDITY 63

exuded from the sides of the egg-tube and surrounds the yolk.
The lower part of the egg-shell is formed before the descent of
the ball of yolk, and stops up the passage of the egg-tube so that
the yolk rests within it until the remainder of the shell is formed.

Fic. 29.—Diagram of a dissection of a female of
the Smaller Spotted Dog-fish to show the
ovary and oviducts. O. the right ovary,
the only one present in the dog-fish ; OD.
the oviduct, containing a ripe egg on its
passage towards the exterior; SG. the
gland of the oviduct, or eggshell-gland; P.
the anterior apertures of the two oviducts ;
OC. the posterior opening of the oviducts
into the ‘‘ cloaca,” behind the opening of
the intestine. (After Milnes Marshall. )

Then the shell, containing
the white and the yolk, is
separated from the sides of
the oviduct and _ passes
down to the end, where it
is “laid,” or driven’ out.
In skates and the rough
dog-fishes there are stiff
rods or long tendrils at the
four corners of the egg.
These are of course formed
with the shell: the lower
projections are the first
part of the shell formed,
the upper the last.

In some dog-fishes, for
instance the common spiny
dog-fish, no eggs are laid,
but the young are born
alive. In this case a shell
of the usual kind is not
formed in the egg-tube,
neither is a shell altogether
absent. In a female opened
before the development of
the young has proceeded
very far the lower part of
each egg-tube is found to
contain two or three yolks
enclosed in a single thin
transparent horny case,
which corresponds to the
egg-shell described above.
But this egg-shell is not
oblong with projections at
the corners, but shaped

64 MARKETABLE BRITISH MARINE FISHES CHAP,

like a cigar pointed at both ends. It is burst when the little
fish are well developed. Thus the eggs in the spiny dog-fish
develop inside the egg-tube, and when the young are born they
are similar to their mother except in size, and are able to swim
about actively and vigorously.

In the male dog-fish the generative organ consists of a flat
solid mass attached to the back of the body cavity on each side
of the intestine. It is similar in position to the ovary of the
female, but the surface is smooth, not bulged out with eggs.
This organ, the milt or testis, consists of a number of tubes,
in which the liquid milt is produced. The milt or semen does

not find its way to the exterior by a direct route, but by the aid |

of a portion of the kidney through which it passes. The tubes
of the testis are in communication at the back of the body cavity
with the tubes of the foremost part of the kidney, and the latter
open into a single larger tube on each side, which like the egg-
tube in the female passes down the body to open into the sac at
the end of the intestine.

The male dog-fish or skate is distinguished, as is well known,
by two long thick projections attached at each side of the vent,
and connected with the hinder paired fins, of which they form
the hinder part. During coition the male inserts these two
organs through the vent of the female, into her two egg-tubes,
and the milt is passed along them. In the males of skates and
rays there is a patch of sharp-pointed spines on each wing,
which is absent in the females, but whether these are used in
the act of copulation or not is unknown.

The eggs of the common spotted dog-fishes (Scyl/cum
canicula and catulus) are attached, when laid, to weeds or other
objects standing up on the sea-bottom, by means of their
tendrils, which are tightly wound round the support. The
manner in which this is effected has been observed in the
aquarium of the Plymouth Laboratory, for these species lay
their eggs freely in captivity. The lower tendrils project first
from the vent, and the female rubs herself against some fixed
body, swimming round and round about it. The tendrils soon
catch fast in some slight projection, and the egg is thus dragged
out and firmly bound to the fixed object at the same time, and
there it remains while development proceeds. The large rough
dog-fish, or nurse-hound, lays its eggs in this way in some places

es

Ill GENERATION OF FISHES AND THEIR FECUNDITY 65

among sea-weed not far from
low tide they can be gathered by
hand. Besides the two spotted species
there is only one other occurring in
British seas which lays eggs, namely, the
black-mouthed dog-fish (Prestzurus mel-
anostoma), and this species, which is
abundant in the Mediterranean, has been
very rarely taken off our coasts. The
rest of the British sharks and dog-fishes
produce their young alive. All the
ordinary skates and rays, on the other
hand, lay eggs which differ only in size
and minor peculiarities in the different
species. |The electric ray (Zorpedo), the
eagle-ray (A7yliobatis) and the sting-ray
(Trygon) bring forth their young alive.
There is no evidence at present to show
that the egg-laying rays seek particular
localities in which to deposit their eggs.
The eggs are occasionally taken in the
trawl or dredge, and the empty shells
are often cast ashore. They are some-
times called mermaids’ purses.

In the majority of the bony fishes
the condition of the roes and the mode
in which the eggs are produced and
fertilised are quite different. If we take
the herring as an instance, it is well
known that in this fish (Fig. 30) there
isvay Dard) roe) Ot Soft roe jon’ each Side
of the body cavity, and that in the
spawning season these are very large so
that the abdomen of the fish is distended
by them. The roe or hard roe occurs
in the female fish and contains the eggs
or spawn, the milt or soft roe belongs
to the male and contains the white
milky liquid which must act upon the
eges before they can develop. Careful

low-water mark, where at

Fic. 30.—Diagram of a Her-
ring with its body cavity laid
open at the lower edge, to
show the roes and intestines,

&c. L. liver, in front of
which is seen the heart ; S.
the stomach; I. the intestine;
SP. the spleen ; O. the roes
or milts opening together
behind the opening of the
intestine.
F

66 MARKETABLE BRITISH MARINE FISHES CHAP.

examination shows that the roe, or hard roe as it is often called, the
ovary as naturalists call it, is in the form of a sac, which is smooth
on the outside and hollow inside. This sac has only one opening,
the opening by which the spawn escapes, on the lower side of
the fish, behind the vent. There is a roe on each side, and the
two open at a common opening (Fig. 32). The inner wall of
the sac is not smooth but thrown into a number of ridges run-
ning along the length of the sac. These ridges consist almost
entirely of eggs, and together they correspond to the ovary of

Fic. 31.—Diagram of the interior structure Fic. 32.—Similar diagram of the hard
of the soft roe or testis in the Herring. roe or ovary of the same fish.

a dog-fish, a skate, or a hen. The great difference is that the
single eggs are very much smaller, and very much more numerous.

The eggs burst through the surface of the ridges on the inside ~

of the roe, and so become free in its interior, and then they are
squeezed out through the external opening into the water.
Now it was mentioned above that the egg as it escaped from
the ovary in the dog-fish consisted only of the round yellow
yolk, surrounded by a thin delicate skin. The outer parts of
the complete egg, the white and the shell, are added in the
oviduct or egg-tube. In the herring the eggs which are set free

II GENERATION OF FISHES AND THEIR FECUNDITY 67

from the ridges inside the roe are little round balls of yolk, of
course containing a germ, and they are covered with a trans-
parent membrane. These eggs are sent out into the water just
as they are, and no “white” or shell is added to them. In fact,
in all cases throughout the animal kingdom, the essential part
of an egg is the germ, from which as from a centre the forma-
tion of the new creature commences. A greater or smaller
quantity of yolk, which is the food of the germ, is connected
with it, and yolk and germ are contained in a membrane or
skin. If a number of hen’s eggs were carefully broken, the
yolks separated and placed in water, they would correspond
exactly to the eggs of the herring or the salmon. The white
and the shell are not primary and essential parts of the egg,
though they are required under certain conditions. In the case
of the frog there is no shell, but each yolk is surrounded in the
egg-tube by a kind of “white” which swells up in water when
the spawn is laid, and causes a number of the eggs to stick
together in masses.

An egg which is surrounded by a strong tough shel] must
be fertilised before the shell is formed, and accordingly in dog-
fishes and skates as in birds the sperms are introduced into the
upper part of the egg-tube, where fertilisation takes place. But
the eggs of bony fishes are shed into the water unfertilised ;
there is, properly speaking, no egg-tube, and with the exception
of a few species no milt is introduced into the cavity of the roe.
These eggs come into contact with the milt when they are
expelled from the roe of the female into the water, and it is an
interesting fact that there is a minute aperture or pore in the
egg membrane for the admission of the sperm. This aperture,
technically known as the mzcropyle, is represented in the diagrams
Figs. 45-48, p. 95.

In the case of the dog-fish or skate the eggs are laid singly
or in pairs at considerable intervals, as the formation of the shell
occupies a considerable time, and only two yolks come from the
ovary together. The period of egg-laying too extends over a
considerable part of the year. The number of eggs laid in one
season could be ascertained, but I do not know of any special
inquiries on this point. On the other hand the period during
which eggs or spawn are produced by the bony fishes is limited
to a few months, and in the case of a single fish may last only a

it 2&

68 MARKETABLE BRITISH MARINE FISHES CHAP.

few days or weeks. The period is annual, and occurs at about
the same time every year. The total annual crop is shed, and
then for the rest of the year no more eggs are laid, but the forma-
tion of next season’s crop goes on in the roe or ovary. The total
number of eggs produced by a single fish is very large, and has
been carefully investigated. The method by which this is done is
as follows. All the eggs in the roe of a fish, such as a herring, before
it has begun to spawn, will be shed in the spawning process,
that is to say, all that are large enough to be distinguished with-
out a microscope. The whole of the two roes are carefully
weighed, and then a small quantity, say } 0z., is weighed. Then
this selected portion of the roe is gradually boiled, in order to
separate the eggs and make them more distinct. The number
in the selected portion is then counted carefully, and the result
is multiplied by the number of times the weight of the selected
portion is contained in the weight of the whole of the two roes.
For example, suppose the two roes of a herring weigh 8 oz. or
half a pound, and that } oz. contains 1,000 eggs ; then the total
number in the fish is 16,000. Dr. T. Wemyss Fulton published
in 1890! the results of an extensive investigation of this kind.
Some of his figures will be found in the table opposite.

It will be seen that in this list the ling is the most prolific
and the herring the least, although the herring is a more abundant
fish than the ling. This is not so surprising and contradictory
as it appears, for the ling is a predaceous fish and very much
larger than the herring, and a large predaceous fish must neces-
sarily be less numerous than the smaller fishes on which it preys.
Next to the ling in fecundity is the turbot, also a large predaceous
fish, and next comes the cod. The turbot and plaice may be
compared with similar results to those just mentioned in reference
to the ling and the herring. The turbot is much less numerous
than the plaice, although the latter produces a much smaller
number of eggs from each individual fish.

Such facts as these, which very commonly come before us in
the study of the conditions affecting the relative abundance of
different animals, show that mere fecundityis byno means the most
important condition. If everyegg produced bya fish developed into
an adult individual the increase in numbers would be very rapid

1 «*« The Comparative Fecundity of Sea-Fishes,” znth Ann. Rep. Fishery Boara
for Scotland.

Ill GENERATION OF FISHES AND THEIR FECUNDITY 69

indeed, so that in a very short time the multitudes of one species
would be enough to fill the sea, to say nothing of a number of

species together.

As it is quite clear that fishes producing a few

Species. Length. Weight. No. of Eggs.
Herring Dre in. 30,000

Py 11g in. 26,000

* IIdin. 47,000

fe IT in. ao 21,000

Cod 374 in. 23 lbs. 3,970,000

a 38 in. 214 lbs. 6,652,000

35 35 1n. 16 lbs. 2,963,000

| Haddock 22 in. 4 lbs. 806,000
| is 27 in. 64 Ibs. 546,000
| . 184 in. 2 lbs. 6 oz. 399,000
. 164 in. 1 lb. 7% oz. 349,000
5h 163 in. 14 lbs. 150,000
Whiting I1gin. 104 02. 109,000

3 164} in. 144 oz. 131,000

Ling 61 in. 54 lbs. 28,361,000

5p 45 in. 25 lbs. 18,520,000

ss 45 in. 184 lbs. 12,306,000

an 62 in. 40 lbs. 14,525,000
Plaice £74 10. 3 Ibs. 4 oz. 223,000

an 174 in. 2 lbs. 10 oz. 148,000

95 22 in. 4 lbs. 34 oz. 487,000

a 221 in. 4 lbs. 113 oz. 324,000

3 204 in. 3 lbs. 124 oz. 323,000
Lemon or 15 in. 24 lbs. 672,000
Merry Sole 123 in. 154 OZ. 150,000
Flounder 147 in I lb. 94 oz. 1,638,000

ne 123 in. 133 oz 711,000

Be 103 In. 12 oz. (nearly) 561,000

Dab 83 in. 128,000

i 7+ in. 79,000

Ss 81 in. ane 109,852

Sole 173 in. I lb. 15102. 750,000

<5 1S in. 2lbs. 54 oz. 553,000

- 16 in. I lb. 10 0z. 409,000
Turbot 28 in. D7 lbs: 5 0z. 9,161,000

S 24 in. 14 lbs. 8,104,000
Mackerel 16in. 1 Ib. 83 oz. 639,000

a5 16 in. 1 lb. 82 oz. 689,000

Grey Gurnard 12} in. 93 oz. | 192,000
ee 14 in. 12°" Oz: 244,000

56 144 in. 14 Oz. 269,000

5 134 in. 135 OZ. 297,000

Ae 154 in. 19 oz. 278,000

thousand eggs are often more abundant, in spite of hosts of
enemies, than those which produce millions, we learn that the
production of a very large number of eggs usually implies an

7O MARKETABLE BRITISH MARINE FISHES CHAP.

enormous destruction of eggs and young, either by the action of
enemies or by surrounding conditions or from scarcity of the
natural food. Thus in the case of the herring, which feeds both
in the young and the adult state chiefly on the swarming minute
creatures in the sea, an abundance of food is usually everywhere
available, while only those young turbot or ling can survive which
happen to find smaller fishes than themselves to feed upon, and
their prey is not to be found in every part of the sea, so that a
large proportion are starved to death. On the other hand if the
number of the young of the predaceous fishes were smaller, then
the chances of some of them finding prey would be fewer, and
consequently the abundance of the species would diminish.
Careful consideration shows that the production of large numbers
of eggs and young leads to the same result as the protection and
nourishment by the parents of a smaller number. There are
plenty of instances in which on both systems the abundance of
the adults neither increases nor diminishes greatly ; for example,
the spiny dog-fish which produces only six or seven young at a birth
is as abundant as ling or turbot. The one system may be com-
pared to the starting of a vast number of small boats of which
only a small percentage escape the perils of the sea and reach
port, the other to the equipment of a few large steamers which
are nearly certain to accomplish their voyage safely and
punctually.

The eggs of different fishes are of different sizes. Those of
the trout and salmon are much larger than those of the most
familiar sea-fishes, and partly in consequence of this, but chiefly
because they are deposited in rivers and streams, they were well
known to sportsmen and naturalists long before the buoyant
eges of sea-fishes were discovered. The egg of the salmon is
about + inch in diameter. One of the largest among the eggs
of sea-fishes, namely that of the plaice, is only 34; inch across,
and the majority are little more than ,'; inch.

In the spawning season a certain proportion of the female
fish captured are ripe, and when they are handled or gently
squeezed the spawn escapes freely from them. The spawn if
taken on the hand forms a transparent mass which is easily seen
to be composed of a large number of round grains, similar in
appearance to glass beads. When the roe is opened before the
spawning season the eggs are seen to be minute white grains,

III GENERATION OF FISHES AND THEIR FECUNDITY 71

looking somewhat like grains of chalk. If the roe of a
spawning fish is examined it is seen that some of the eggs have
become larger and transparent, while a portion of the roe still
consists of the chalk-white smaller eggs. In fact, the eggs
become more or less clear and transparent when they are ripe,
and then they become loosened from the sides of the roe, fall into
the cavity, and so make their way to the exterior.

The difference between the unripe and the ripe egg is due to
a change in the condition of the yolk, which becomes more liquid
and less granular. But there is a still earlier condition of the
egg in which there is no yolk at all. In this condition the egg
consists really of germ only, and is a minute mass of trans-
parent living substance. The formation of the yolk commences
some months before the spawning season, and the presence of
opaque eggs in the roe, of eggs which have the appearance of
separate grains to the naked eye, is a sure sign that the fish
would have spawned in the following season. In small fish
however, and in large fish some time after the spawning season,
the roe is usually found to be quite small and, when cut open, to
show no appearance of distinct grains. It appears soft and
contains only the very young eggs in which no yolk has been
formed. It is often said of fish in this condition that they have
no roe in them, but the roe though small is always present, and
accurate knowledge of the changes through which it passes is
very necessary in considering the question of the age and size at
which fish begin to breed.

The generative organs of the male fish are very different in
structure from those of the female. In the herring and nearly
all other bony fishes the male organ, milt as it is sometimes
called, testis as naturalists call it,is a solid body. That is to say,
it is not a sac with a large internal cavity like the roe, but when
cut through appears to be a mass of substance without cavities,
although of a soft nature and when ripe full of liquid. It is
really composed of a number of tubes which join with one another
like the tributaries of a river until a single tube is reached which
opens to the exterior with that of the opposite side by a single
aperture (Fig. 31). In consequence of the number of these
tubes the testis has really a spongy structure, and the liquid milt
is produced in the tubes, and pressed out at the external opening
into the water in the spawning process. The milt mixes with the

72 MARKETABLE BRITISH MARINE FISHES CHAP:

sea-water and there acts upon the eggs shed at the same time by
the female, and so the eggs are fertilised.

The milt both in bony fishes and in skates and dog-fishes
appears to be a thick white liquid. It really consists of innumer-
able minute solid particles suspended in a transparent liquid.
These particles can only be distinguished with the help of the
microscope. They are called spermatozoa, or, for the sake of
brevity, sperms. The most remarkable fact about them is that
when alive and fully developed or “ripe” they are in constant and
active motion. Each consists of a thicker, denser portion, the
head, to which is attached a very thin long lash or tail, and the
motion is due to the incessant vibration of the tail from side to
side, which drives the sperm rapidly through the liquid containing
it, just as a tadpole is propelled through the water by the move-
ment of its tail. The extraordinary activity of the multitude of
sperms in a drop of living milt examined under the microscope is
an interesting spectacle, and forcibly reminds the observer of a
number of animalcule in a drop of water. In fact, when first
discovered the sperms were called the animalculz of the semen,
and the part they played in the fertilisation of the egg was not
understood.

The head of the sperm differs in shape in different orders of
fishes. In the skates and rays it is a long rod having a spiral
form, in bony fishes generally it is nearly globular, but in the
herring its length is somewhat greater than its breadth. Fig. 33
represents the shape of the sperms of certain fishes as seen
when highly magnified. The side of each square in the figure
represents zy o'99 inch, so that the extremely minute size of the
objects is plainly evident ; the head of the sperm of the thorn-
back ray is a little more than ;.2,5 inch in length, that of the
herring about 3,459 inch, of the pike a little less, while in the
plaice and sole the diameter of the head does not exceed
t0,s00 inch.

Fertilisation consists in the entrance of one of these sperms
into the egg, where its head unites with the germ, and the latter
is then capable of development. It would be utterly out of the
question to consider the number of these sperms in the milt of
the male fish: it would be as easy to give the number of hairs
in a good head of hair, or the number of grains in a ton of sand.
But it is a curious fact that only one sperm is needed to

Ill GENERATION OF FISHES AND THEIR FECUNDITY WS

effect the fertilisation of each egg, the great number are only
advantageous in securing that every egg shall be fertilised.

In the herring the hard roe of the female and the soft roe of
the male are both smooth outside, and both equally large. But
although their connections and their mode of construction are
essentially the same in other fishes their appearance and size are
in many cases very different. In the flat fishes such as the
plaice, sole, turbot, &c., the soft roe of the male is much smaller
than the hard roe of the female. The latter has its opening in

AM

|

|!

Fic. 33.—Sperms of various fishes, highly magnifizd. A, those of the Thornback
Ray ; B, of the Herring ; C, of the Pike; D, of Plaice or Sole. Each side of

the squares represents y¢'5¢ Inch.

|
|

front of the ventral fin, not far behind the head, and extends
back on each side beneath the flesh of the body, nearly to the
root of the tail. The soft roe, on the contrary, is a small white
mass at the back of the central cavity of the fish. The
difference in size between the male and female roes is greatest in
the sole, and their appearance and position in this fish are clearly
shewn in the four illustrations here given. Fig. 34 represents the
appearance of the belly cavity of a female sole laid open by the
removal of the skin and flesh covering that cavity on the upper

74 MARKETABLE BRITISH MARINE FISHES CHAP.

side. The organs are seen in their natural position. L is
the liver with the large globular gall-bladder attached to it. G
is the gut or intestine, bent upon itself three times so as to lie in
four lengths side by side. Behind the gut is seen the hinder
part of the hard roe, R, the front part being covered and con-
cealed beneath the gut. Fig. 35 shows what is seen when the
gut and the liver are removed. Nearly the whole length of the
roe is now visible, ending in front in a tube which joins another
tube from the roe of the lower side of the fish to open on the
edge of the body behind the head. The roe on each side rests
against a series of bones lying in the middle region of the body.

When a male sole is cut open in a similar manner, as seen in
Fig. 36, the intestine and the liver are seen as in the female, but
no roe is visible. In fact until a few years ago a deal of mystery
hung over the question of the male sole, and it was even doubt-
ful to fishermen and others whether there were two sexes in the
sole at all. The truth is that the soft roes of the sole are very
small. Their size and position are shown in Fig. 37, representing
the appearance of the belly cavity after the liver and intestines
have been taken out. The soft roes or milts, indicated by the
letter M, are small oval white bodies lying at the back of the
central cavity, and connected with the edge of the body by two
cords, in which the milt is conducted to the exterior. The ex-
ternal opening is on the upper side of the fish just behind the
opening of the gut.

In the cod, haddock, and other fishes of the cod family the
hard roes are short, thick bags, joined together at their hinder
ends and placed at the back of the belly cavity. The soft roes
have a very different appearance to that seen in the majority of
fishes. They are white narrow frills, in a position correspond-
ing to that of the ovaries. They consist of a pair of narrow
thickened bands attached by thin membranes to the back of the
cavity: they are very much longer than the attached edges of
these membranes and consequently are thrown into zigzag folds.

Dr. Fulton has investigated, besides the comparative fecundity
of the sea fishes, the proportions between the numbers and sizes
of the two sexes. He did this by study of the records of the
sizes and sexes of all the fish captured in the trawl of the inves-
tigation steamer of the Scotch Fishery Board, supplemented by
the examination of numbers of certain kinds of fish captured in

IIL GENERATION OF FISHES AND THEIR FECUNDITY 75

.
’

v
ie)
=
Go}
4
PA s
Unhy os
=O D
ss
=)
s
S
o)
oe
“2
a=
n
re)
ary
—
s
4
=
pa)
fae]
S4
o
A=}
ow
om}
Sa! LTS
ale)
er
=
a
AD OL
=
ao U
CNS
_~
fo)
GG
Va
ea)
a
~ Uv
a
=)
dq O
OG
a4
Oo
oH
b=
Brn

G, the gut

4.—The abdomen of the female sole, 1

2
J

T.

Fic

Ss:
SS

other ways. The reliability of the results depends upon the
question whether the means by which the fish were obtained
collected all sizes and sexes equally and indifferently. A certain

‘hole length,

seen in its W

Fic. 35.—The same after removal of the liver and gut, the roe

76 MARKETABLE BRITISH MARINE FISHES CHAP.

mode of fishing might capture fish only above or below a certain
size ; in the case of the conger if hooks of large size were used only
females would be taken by hook and line. But as the Board’s
steamer Garland fished with a small-meshed beam tawl, and on
various grounds, and as large numbers of fish of all sizes were
examined, we may justly consider Dr. Fulton’s conclusions
to be sound. The proportions are expressed by giving the
number of females to every 100 males, and the average length
of the females compared with the average length of males taken
as 100.

Number of females Ratio of length of females
to 100 males. to males at too.

Code: i ae So see LingIe bn a HOS
Haddock <2 ae 5h oS re OS
Whiting... sak ned peer ial ae =e EeLOd
Biboe.. iy 3: 2) Zon a a QO
Plaice a ae 37h sie LAD sid ays aee aL
Dalby ee se ote ae 295 aoe sah i | TOR
Flounder": We te S05 Oe aes ee ZO)
Lemon Sole... = se soo BfOles ae Es LOS
Witch Be Nae ae soo ASKS) Sti oe soo. A
Brill ... o8e me dee eee Ag! te ase ae Ze
Turbot ae +d, ne ne LOS ies — see LS
Halibut ae re ee ae EL5O

Long Rough Dab ... ane soo, Shalt aa 43 “45 - 130
Grey Gurnard se sit ... 409 a ae LOS
Angler ues ov sie cy 20 a oe oe ey)
Lump-sucker we ae Soe 25 ati eH SECO
Cat-fish Sho a Soe ao S50 sae samt
iderning se. a a oe, OS) eke ot ay ?

It is interesting to consider what is the meaning of this
inferiority, in number and size, of the males in the majority of
cases and of the difference between different species in these
respects. The number of males is the same as the number of
pairs of milts, but the size of the males is not necessarily in pro-
portion to the size of the milts. It will simplify matters therefore
to put aside for a time the question of the size of the male fish,
and consider only the proportion of milts to roes in number and
size. We have no reason to suppose that the provision made
for the proper fertilisation of the eggs is insufficient, we may
take it for granted therefore that in all cases the quantity of
milt produced is enough to fertilise all the eggs. Mention has
already been made of the great differences which exist in the
size of the milts in proportion to the size of the male fish, and in
proportion to the size of the roes in the female. An exact inves-
tigation of these differences has not yet been completely carried

Xe)
xo)
LASELO f
Lo sess =
a, Loa
SES! K

7

IIT GENERATION OF FISHES AND THEIR FECUNDITY Th

livers

i G, gut ;

sition.

r natural po

el

]

in t

h the organ

1 open wit

alc

~

male Sole 1

.—Therabdomen of the

<2
LORE

out, but Dr. Fulton has published some of the weights ascertained
in a certain number of species. The whole subject requires
further study and research, and gives rise to problems which are

M, the milts.

Fic. 37.—The same after removal of the liver and gut.

78 MARKETABLE BRITISH MARINE FISHES CHAP.

not only important but attractive. The explanations offered
here must not be considered as by any means complete or final,
but merely as conclusions suggested by our present imperfect
knowledge.

In the herring it has been found that there is very little
difference between the weights of the ripe milts and ripe roes, and
that little is on the side of the milts. In the cod the ovaries
were found to weigh between two and three times as much as the
milts. In the plaice the roes were about seventeen to twenty
times as heavy as the milts, in the flounder about forty times,
while in the sole the inferiority of the milt in size reaches its
extreme. The obvious difference between the herring and the
other fishes mentioned is. that the spawn of the former is attached
to solid objects while the eggs of the latter become free and
separate in the water. Milt when shed into the sea-water diffuses
through a large quantity of it quickly and so becomes much
diluted, and as the water of the sea is usually moving in the tidal
currents in one direction or another the milt is also carried away
at a certain rate from the place where it is shed. From these
causes a considerable proportion of the milt shed by male
herrings where the females are spawning has no chance of
coming into contact with the eggs at all, but is wasted. It may
be said that, while the eggs of some fishes are fixed and those of
others buoyant, the milt is always buoyant. We have here an
obvious reason why the herring should require a large quantity
of milt, and we may conclude that where the milts are as large
as the roes a great waste of the male generative material occurs
in the process of spawning. On the other hand in cases where
the eggs are buoyant and free they disperse in the water and
are carried by currents at the same rate as the milt, and the
result is the same as though both were confined in a small
quantity of still water. There is consequently very little waste
of milt, and a smaller quantity suffices to ensure fertilisation.
In the cat-fish, which like the herring produces fixed eggs,
according to Dr. Fulton’s figures as given above the males are in
number in excess of the females in the proportion of 100 to 79,
but concerning the size of the ripe milts we have no observations.
The males of the lump-sucker, of which the spawn is also fixed,
are said to be much more numerous than the females, although
considerably smaller. But here we have to consider not merely

int GENERATION OF FISHES AND THEIR FECUNDITY 79

the fertilisation of the eggs but the fact that the male keeps
guard over the eggs until they are hatched, and until it is
explained how twenty-five females can supply enough spawn to
keep one hundred males occupied in paternal nursing duties we
can scarcely feel confident that the figures are correct.

It is obvious that the above considerations have no application
to the case of differences in the proportion of milt to roe among
fishes which agree in producing spawn of the buoyant kind.
Other things being equal, we may reasonably suppose that the
disproportion will be greater when the eggs are larger. For the
quantity of milt required will depend on the number of the
eggs, not on their size, and therefore if the eggs are larger the
roe will be larger while the size of the milt remains the same, or
if the size of the roe remains the same the number of eggs will
be smaller, and the milts will be diminished in size. But
according to this reasoning the milt ought to be larger in the
sole than in the plaice, instead of much smaller as is actually the
case, for the eggs in the sole are smaller and more numerous than
in the plaice. The most important consideration is certainly the
rate of spawning, that is to say, the number of ripe eggs shed at
the same time, or in one act of expulsion. Here again more
exact determinations are required, but it is a matter of general
observation that the cod and allied fishes shed their spawn much
more rapidly than the flat-fishes, and among the latter the plaice
flounder, and turbot more rapidly than the sole.

The differences in the rate of spawning become very obvious
when one is pressing ripe eggs from the various fishes for the
purpose of artificial fertilisation. In most cases, for instance in
those of the haddock and plaice, a large proportion of the con-
tents of the ripe roes can be squeezed out and fertilised at one
operation. On the other hand, when I was studying the eggs
of the sole I found always the greatest difficulty in obtaining a con-
siderable number of eggs from a number of spawning fish, while
when squeezing the males I never saw large drops of milt escape
on pressure as in other species, and had to effect fertilisation by
cutting out the milts and mincing and pressing them in a vessel
of sea-water. The differences in the rate of spawning are also
evident from the condition of different roes when they are
minutely examined in the ripe condition. In such roes as those
of the cod and plaice a large proportion of the eggs are found

80 MARKETABLE BRITISH MARINE FISHES Cae

to present the same stage of development, so that it is evident
that after spawning has once commenced there will be no long-
continued production of ripe eggs in succession, but that a large
number will be shed in a short space of time, while in the sole, and
also in the gurnard, eggs are found in all degrees of develop-
ment from the most primitive stage onwards. That the eggs
of the sole are shed in very small numbers at a time has been
strikingly confirmed by the observation of the soles in the act
of spawning at the Plymouth Laboratory.'| Only a small number
of fertilised eggs were obtained each day from a tank contain-
ing a large number of ripe fish, and the eggs appeared to the
observer to be shed one at a time at intervals.

It is evident that if only a few ripe eggs are shed into the
water at one time the quantity of ripe milt which must be
liberated to fertilise them will be very small, while if several
hundreds or thousands of eggs are expelled within a few seconds
or minutes within the same time a hundred or thousand times as
much milt will be required as in the other case. If the forma-
tion of the milt occupied as long a time as that of the eggs, there
would be no apparent reason why the proportion in size between
the male and female organs should differ greatly in fishes that
spawn rapidly and those that spawn slowly. In both roe and
milt there would be a bulky accumulation of eggs and sperms in
process of development. But in the egg there is a gradual
formation of yolk which extends over weeks or months, while
the sperms are minute, contain a small quantity of material, and
can be produced in a few hours. In this fact lies the reason why
a slow spawning roeis so much larger than the milt of the same
species. If we suppose that 5,000 ripe eggs are shed by a sole
per day in the spawning period, and that the growth of an egg
takes three months, then a sole producing 500,000 eggs would
take 100 days to get rid of all its eggs, and on the day it com-
menced to spawn very nearly all the eggs would be present in
the roe in all stages of development or formation. On the other
hand it is extremely probable that the ripe milt necessary to
fertilise 5,0co eggs can be produced in one day or a few days,
and therefore at the commencement of spawning the male organ
would contain not all the milt to be shed in the spawning

1G. W. Butler, B.A. : ‘‘Onthe Spawning of the Common Sole in the Aquarium,”
M. B. A. Journal, vol. iv., No. 1, p. 3.

III GENERATION OF FISHES AND THEIR FECUNDITY SI

period but only the small quantity required for the first day or
first few days, more being produced after the first quantity was
shed.

The comparison of the grey gurnard with the angler with
respect to the relations of the sexes and the rate of spawning
corresponds to that between the sole and plaice. The gurnard
spawns gradually, and although no special observations have
been made on the size of the milts there is, according to Dr.
Fulton, a very great inferiority on the part of the males in point
of number, the females being more than four times as numerous.
In the angler, on the contrary, all the eggs are shed simul-
taneously, and the males were found to be more abundant
than the females in the proportion of I00 to 26. There
is, however, an additional reason why in the angler a large
quantity of milt should be necessary. The eggs although
buoyant do not separate, but remain connected together in a
continuous sheet. Owing, therefore, to the diffusion or scatter-
ing of the milt in the water there is doubtless a considerable
waste of that substance in the process of fertilisation.

Although the small size of the milts in the slow-spawning
fishes, especially in the sole, has attracted most attention, it is
also true, as might be expected, that the roes in these species
are smaller in the spawning season than in fish which spawn
quickly. Ripe eggs being larger than partially developed eggs, the
more ripe eggs present at the same time the more enlarged will
be the roe. But for the reasons already given the differences are
not so extreme as in the case of the male organs. Dr. Fulton has
referred to the very different degree of ease with which the eggs
are carried in different species. In the plaice, flounder, cod, had-
dock, and several others, all producing large numbers of ripe eggs
simultaneously, the body is much swollen or distended by the
ripe roes in the spawning season, while in the sole, gurnard,
and others the enlargement of the belly in the gravid condition
is much less striking. Great enlargement or distension of the
body of course implies that the ripe roes are larger in proportion
to the size of the fish than in the opposite case. The internal
organs, especially the stomach and intestines, are necessarily
compressed by the enlarged roes, and this is the reason why so
many fishes take little or no food during the spawning period.
Gravid female cod, for example, are taken in large numbers by

G

82 MARKETABLE BRITISH MARINE FISHES CHAP.

trawlers in the spring of the year when the line fishermen catch
none but male, immature, or spent fish.

To return now to the consideration of the size of the male
fish in comparison with that of the female, it cannot be said that
the differences are at present fully explained. The size of the
male which produces the milt is of no importance to fertilisation.
It appears however that the male fish are smaller than the
females in those species in which the milts are much smaller than
the roes, although there is by no means a close correspondence
between the fish and the milts in this respect. For example,
the males in the cod and similar fishes are usually larger than
the females, although the milts are smaller than the roes, and in
the sole and other flat-fishes the males are by no means as
inferior in size as are the milts in comparison with the roes.

Owing to the fact that fertilisation of the eggs of bony fishes
naturally takes place in the water outside the bodies of the
parent fish, and in consequence of the ease with which the
ripe milt and eggs can be obtained from the fish by gentle
pressure on the abdomen, artificial fertilisation of the eggs is
rendered possible and in most cases easy. All that is required
is to squeeze the ripe eggs and a little ripe milt into a vessel of
clean sea-water. But in the practical application of this process
the questions of the rate of spawning and the size of the soft
roe are of considerable importance. In the case of fishes which
spawn rapidly—for instance, the herring, cod, plaice, or flounder
—all or a large proportion of the total number of eggs pro-
duced by the fish in one season can be fertilised at one time.
The hatching of the eggs so obtained depends on placing
them under conditions suitable to their healthy life. But in
certain cases artificial fertilisation is difficult. For instance in
the sole only a small number of ripe eggs can be obtained from
a single fish, and to fertilise these it has generally been found
necessary to open the male fish, take out the small milts, and
squeeze them up in the water containing the eggs. It has been
found preferable to keep the spawning fish in ponds suitably
arranged, and collect the fertilised eggs naturally shed. In this
way the risk or certainty of injuring the fish by squeezing is
avoided. But here in some cases another difficulty arises. The
plaice and cod under such conditions are found to spawn freely,
but until the year 1895 the sole had never spawned in the tanks

III GENERATION OF FISHES: AND THEIR FECUNDITY 83

of the Plymouth Aquarium, although numbers had lived in health
there for years. It was found that the female fish became
swollen in the spawning season as though the roes were enlarged,
but no soles’ eggs appeared in the tank, although in the same
tank plaice spawned freely. After a time the swelling of the
females began to diminish, and on killing some and opening
them it was found that the cavities of the roes contained the
dead and shrunken remains of ripe eggs. Evidently in con-
sequence of the conditions of confinement the eggs after devel-
oping were not shed in the natural way, but died within the roe,
and were then gradually expelled. Turbot and brill have also
hitherto failed to spawn in confinement. In squeezing fish to
obtain fertilised eggs it is important that only ripe eggs should
be pressed out. If too much pressure is applied some of the un-
ripe also escape, and can easily be distinguished by their smaller
size and chalk-white or yellowish appearance.

The spawning season of a fish is the period during which
some individuals are found to be ripe, and it may last three, four,
or five months. The majority of our common sea-fishes spawn
in the first half of the year. The plaice is one of the earliest,
beginning to spawn in January and going on to the middle or
end of April. The cod spawns in the North Sea from February
to May, the sole from April to July. The herring appears to
have two spawning periods—one in winter or spring, one in
summer or autumn, in the same neighbourhood, the dates
differing in different districts. But there is good evidence that
like other fishes the same herrings spawn only once a year, and
that there are races which spawn in winter and others which
spawn in summer, the spawning grounds of the former being
nearer shore and nearer the mouths of rivers than those of the
latter.

There is one family of fishes which forms an exception to the
general rule in the circumstances of its generation. This is the
family of the eels. Much still remains obscure and unknown in
the life-history of the eel and conger, but what is known is
sufficiently remarkable. Ripe eels have never yet been obtained,
all that is known of them is that they go down the rivers in
autumn to the sea, and probably spawn there, and that young
eels two to four inches long return in the following spring up the
rivers. It is fairly certain that the old eels die after spawning.

GrZ

84 MARKETABLE BRITISH MARINE FISHES CHAP. III

Ripe conger have never been taken from the sea, but they live
well in aquaria, and from study of them in that condition it has
been found that the males are very much smaller than the
females, that the females after feeding and growing for several
years cease to feed, and that their roes then develop. The eggs
of the conger are very small, and the roes are not closed sacs but
open ribbons with the eggs on one side. The males in aquaria
become ripe : the fish do not exceed two and a half feet in length,
but the milts are large, filling the whole belly cavity: they live about
six months in the ripe condition without feeding and then die.
The females also die with enormously enlarged roes, but before
the eggs have become ripe. There can be no doubt that in the
sea conger of both sexes die after spawning. The eggs of some
fish of the eel family have been taken in the sea, but those of
the conger are not yet known. It is known that the fecundity
is great, various calculations having given the number of eggs
in a single female at from three to seven millions. The females
appear to benot only larger but more numerous than the males.

CHAPTER TV
THE EGGS AND LARV# AND THEIR DEVELOPMENT

IT follows from the description of their formation, given in
the preceding chapter, that the large egg of a dog-fish or skate
consists, like a hen’s egg, of three parts, the shell, the white, and
the yolk. The shell differs from that of the bird’s egg in shape
colour, and substance. In shape it is somewhat oblong with a
tendril ora straight horn at eachcorner. Fig. 38 shows the shape

Fic. 38.—Egg of the Larger Spotted Dog-fish, or Nurse-hound ; after Day.

of the egg of the larger spotted dog-fish ; the eggs of the skates
and rays have horns instead of tendrils, and are broader in
proportion to their length. The colour is from light brown to
black, deepening gradually after the eggs are laid. The sub-
stance of the shell is tough, fibrous, and flexible, and contains
no lime, the presence of which in large proportion causes the
shell of the bird’s egg to be hard and brittle. The white, as
in the bird’s egg, is a thick transparent liquid. The yolk con-
tains the essential part of the egg, namely a spot of living
substance on its surface which is the germ. No distinct
membrane appears to exist on the surface of the yolk. The
yolk itself is yellow in colour, of a semi-liquid character, but

made up of minute drops.

86 MARKETABLE BRITISH MARINE FISHES CHAP.

The development of the young fish in these large eggs,
whether inside or outside the mother, takes several months.
Except in a few species, none of which are common in British
waters, there is no difference in the course of the development
between the eggs which develop in the egg-tube or uterus and
those which develop in sea-water. The process com-
mences by the growth of the germ into a membrane or skin which
spreads round the yolk. At one point this skin is, as it were,
pinched up and thickened to form the commencement of the
young fish, which is called the embryo, and at first is very small
compared to the ball of yolk on which it lies. The embryo as
it grows and develops is nourished by the yolk, which therefore
gradually decreases. When the gill-slits are formed, long
thread-like gills develop and hang out a long way beyond the
slits as delicate fringes. When the embryo has acquired
generally the shape of the young fish it is connected with the yolk
by a narrow hollow stalk, and the interior of the yolk-sac com-
municates with the interior of the stomach. This stalk is
situated just behind the front pair of fins, and when the young
fish is hatched or born the yolk and the stalk have disappeared,
the last sign of them being a sort of navel or soft place in the
belly where the yolk-stalk was previously situated. No part of
the yolk is separated, it simply dwindles away as it is gradually
consumed to nourish the developing fish. The gradual growth
of the little fish in the egg of the smaller spotted dog-fish can be
seen through the partially transparent shell, and has been on
view from time to time in the aquarium of the Association at
Plymouth.

The young fish when hatched or born has all the characters
of the adult fish, and immediately enters upon the same mode of
life.

The eggs of the bony fishes consist only of the yolk con-
taining the germ, and surrounded by the enclosing membrane.
It is better to avoid calling the latter the shell, because it is
different in nature from the shell of the bird’s egg or of that of the
dog-fish. The eggs of different kinds of these fishes differ in size,
in proportional weight, some being heavier and some lighter than
sea-water, in the character of the membrane, in the proportion
which the quantity of the germinal matter bears to that of the
yolk, and lastly in the appearance and structure of the yolk

IV EGGS AND LARVA AND THEIR DEVELOPMENT 87

itself. These differences do not correspond in all cases to the
differences between the adult fishes, although sometimes certain
peculiarities of the egg are found in all the members of one
family and not in other families.

The character of the enclosing membrane is important,
because it has a good deal to do with the conditions under which
the eggs are placed during development. With respect to these
conditions the eggs are of three kinds: (1) those which are
heavy, but free or separate; (2) those which are heavy and
attached ; (3) those which are light and separate. The last kind
occur only in the sea.

Of the first kind the salmon family supply the most im-
portant instances. In eggs of this kind the outer surface of the
egg-membrane is smooth, without projections, and hard, so that
the eggs have no tendency to adhere to one another or to sur-
rounding objects. The eggs of salmon and trout are deposited
in the gravel of the bottom of running streams, the female fish
digging a trough in the gravel, in which she deposits the eggs,
and then heaping more gravel over them. The eggs of the
salmon are about one-fourth of an inchindiameter. The eggs of
the shads also lie at or near the bottom in a free condition, and
are deposited in the tidal water of estuaries, or in the fresh water
of rivers. Theonly other case among British fishes is that of
the turbot (Lota vulgaris), which, though a fresh-water fish,
belongs to the cod family. Its eggs lie loose and separate at the
bottom of the water.

Heavy adhesive eggs are laid by nearly all other fresh-water
fishes, and by a great many marine fishes which live near the
shore. In the majority of these the surface of the egg-membrane
is smooth but sticky when the egg is first laid, afterwards harden-
ing and so firmly attaching the eggs to one another or to other
objects in the water. The eggs of the sturgeon are attached to
stones, &c., at the bottom of rivers. The eggs of the carp family,
all of which live in fresh water, are attached to water plants, and
so also are those of the pike and other members of the pike
family. The eggs of the herring are similar in this respect.
Each egg of this fish is six-hundredths of an inch in diameter.
The spawn is deposited on rough gravelly or stony ground, or
shingly banks in the sea at various distances from the shore, or
in certain cases, as in the Baltic, in estuaries where the water

88 MARKETABLE BRITISH MARINE FISHES CHAP.

is so fresh that the spawn is actually found attached to fresh-
water plants. Fig. 39 shows the appearance under the micro-
scope of a single herring egg in the living condition with parts
of the membranes of its neighbours to which it adheres. It is
worth noting that round adhesive eggs can only touch one
another and stick to one another at separate places, not all over
the surface. There are thus ina clump of eggs spaces or channels
left where the eggs are not touching, and where, therefore, water
can pass through the mass. However, in spite of this, a clump
or mass of adhesive eggs sticking together is more difficult to

Fic. 39.—Living Egg of the Herring, magnified.

keep alive than an equal number of separate eggs, in conse-
quence of the liability of the eggs in the clump to become
suffocated. Living eggs, like living fishes, require a constant
renewal of clean water, water containing dissolved air, and the
more eggs there are in a small space the more rapid the change of
water which is necessary tothem. In natural conditions, herring
spawn receives a sufficient change of water from the flow of
the tides. The herring is the only one of the British members
of its family whose eggs are of the adhesive or fixed kind. We
have seen that the eggs of the shads are free and develop at the
bottom of the water, while the eggs of the sprat and pilchard are

IV EGGS AND LARVAE AND THEIR DEVELOPMENT 89

free and float in the sea. In the perch family, among the spiny-
finned fishes, the fresh-water perch attaches its adhesive cggs
to fresh-water plants, while the bass (Labrax /upus) and other
marine forms produce floating eggs. The commoner fishes
whose adhesive spawn is deposited near the sea shore are the
gobies, the blennies, the suckers, and the shallow-water Cottida,
commonly called sea-scorpions or hard-heads. The eggs of the
common blenny or shanny are attached in a single layer to the
surface of rocks. Those of another species which were examined
at the Plymouth Laboratory were attached to the sides of the
empty marrow-cavity of an old beef-bone. The eggs of the

hth
ES
= aa

Fic. 40.—Egg of the Sea-snail (Zzfarzs) as seen when alive and magnified.

gunnel, another member of the blenny family, forma round mass
which is not fixed, but lies free on the ground. The cat-fish or
wolf-fish is the largest fish of the same family, being usually two
or three feet in length and sometimes reaching six feet. Its eggs
were discovered by Prof. McIntosh to be large and fastened to-
gether into a mass of considerable size lying on the sea-bottom.
The eggs of the two species of Coftws, the sea-scorpion and the
father-lasher, so well known for their large round heads, armed
with strong spines behind, form small roundish masses attached
to stones, rocks, &c., between tide marks.

The eggs of the lump-sucker are large, and deposited in
irregular masses of considerable size not far from low-water

90 MARKETABLE BRITISH MARINE FISHES CHAP,

mark ; those of the sea-snails or diminutive suckers (Lzparis)
form rounded masses not much larger than a marble, which are
attached to the forks of branching zoophytes, very frequently to
a species which is common on the east coast and called
Hydrallmannia. ‘This spawn has been frequently mistaken both
by fishermen and naturalists for the spawn of the herring,
especially in former years before the characters of the eggs of
different fishes had been thoroughly investigated. The indi-
vidual egg, however, is a little smaller than that of the herring,
and, as seen in Fig. 40, has an altogether different character. The
yolk contains several oil-globules. The still smaller sucker fishes,

Fic. 41.—Egg of the Double-spotted Sucker (Lepadogaster).

called Lepadogaster, deposit their eggs, which are oval and
somewhat flattened, on the inner surface of empty shells. Fig. 41
shows the egg of one of these, the double-spotted sucker. The
eggs of the gobies are peculiar, having a long, spindle-like form,
one end of which is attached to a smooth surface by means of
fibres which project all round it and form a network, somewhat
like rootlets (Fig. 42).

Eggs which are free and carried about at the mercy of tides
and currents cannot receive any care or protection from the
parent fish, but marked parental solicitude and exertion are ex-
hibited by many of the commercially useless fishes which pro-
duce attached eggs. Asa rule it is the male parent which in

IV EGGS AND LARVA AND THEIR DEVELOPMENT gI

these cases undertakes the duties of a nurse. The male gobies
make a home for the eggs, it can scarcely be called a nest, and
remain in it until the eggs are hatched. The common sand goby
when about to become a father scoops out
the sand from beneath an empty shell, usually
that of a Pecten (commonly called clam, or
scallop), and invites females to lay their eggs
in the domicile thus simply prepared. The
female deposits her eggs on the lower surface
of the shell, which forms the ceiling of the
nursery, and the male remains on guard.
The action of his pectoral fins is necessary
for the well-being of the eggs, for without
their movement the eggs would die of suf-
focation. The object of the father’s exertions
is therefore chiefly to secure aquatic ventila-
tion of the cavity in which his progeny are
developing. The butter-fishes or gunnels,
common shore fishes belonging to the blenny
family, roll the eggs into a ball after they are
laid by coiling their bodies round the mass, Fic. 42.—Egg of a

the male and female taking possession of the specles OF Cole:
a 5 from lower side of
eggs alternately. Fig. 43 is from a sketch of stone on shore at

i al h.
one of these fishes with a mass of eggs as Ralnout

observed in the St. Andrews Laboratory by
Mr. Holt. The parents remain with the eggs until they are
hatched.

The large lump-sucker (Cyclopterus lumpus) is another species
in which the male keeps guard over the eggs and keeps up an
artificial flow of water over and through the mass of spawn,
which is attached to rocks, posts, or piles in the water. There
are also fishes which are true nest-builders. The commonest
instances of this are afforded by the sticklebacks (Gas¢erosteus and
Spinachia). Two species live in fresh water, the three-spined
and the ten-spined, but the larger fifteen-spined species occurs
in the sea near shore, and in the brackish waters of estuaries.
According to Buckland’s descriptions the nest of the fresh-water
forms is made of fibrous materials resting on the ground, with a
hole in the top, and the male fish frequently places himself
above the nest with his snout towards the opening, fanning the

Q2 MARKETABLE BRITISH MARINE FISHES CHAP.

eggs inside with his pectoral fins. But the sea stickleback makes
a nest by binding loosely together the fronds of growing sea-
weeds by means of a thread which he spins from his own body.
It has recently been proved that this thread is a secretion from
the kidneys, which is produced only in the breeding season.
The mode in which the eggs are protected in the pipe-fishes
is still more remarkable. They might fitly be called the
kangaroo-fishes, but the pouch is in the male parent instead of
the female. The male in the common or larger brown pipe-
fish, and in the broad-nosed pipe-fish, which is green in colour,
has a pouch beneath the tail behind the vent. The pouch is
formed by two long thick folds of skin which meet in the middle
line, but are not joined together. Into this pouch the eggs are

Fic. 43.—Butter Fish with its mass of spawn; after Holt.

received when shed by the female, the male fertilising them at
the same time, and there they remain until they are hatched,
when the young pipe-fishes, which are about an inch and a half
long and similar to their parents, escape. In the snake pipe-
fish, the body of which is smooth and rounded, there is no
pouch, but the eggs are attached to the skin of the male in front
of the vent. One species called the worm pipe-fish is very
small and slender, and is often found under stones at low tide,
on the south coast.

It has been mentioned that the eggs of the gobies are
attached not simply by an adhesive surface but by special
threads or fibres. Such special modes of attachment of varying
kinds occur in the eggs of other fishes. In some adhesive eggs
of the ordinary kind there are indications that the egg-membrane

IV EGGS AND LARVA AND THEIR DEVELOPMENT 93

is composed of two layers, an inner and an outer. In the egg
of the smelt or sperling (Osmerus eperlanus), one of the salmon
family, the outer layer breaks at one part of the surface of the
egg and separates, turning inside out as it does so, and remain-
ing firmly attached only at one small circular patch. The
separated membrane is adhesive when the egg is first shed, and
attaches itself to objects in the water, e.g. the piers of bridges
or posts in the rivers where the fish
spawns, or the stones of the river
bed. The eggs are thus suspended
from their support by the flexible
outer membrane (Fig. 44). It has
been mentioned that in all the eggs
of bony fishes there is a small
opening in the egg-membrane
called the micropyle, through
which the sperm enters in the
process of fertilisation. In the
egg of the smelt this opening is
in the centre of the circular patch
over which the suspending mem-
brane remains attached.

In other cases the outer mem-
brane is represented by threads or
cords which are attached to the
ege-membrane at two opposite
regions and become fastened to Fic. 44.—Egg of the Smelt, with
foreign objects or entangled with its suspending membrane.

' those of other eggs of the same

fish by their free outer ends. This is the case in the eggs of
the gar-fish or long-nose (Le/one vulgaris) and other fishes of
the same family, namely the skipper or saury pike (Scombresox)
and the flying-fishes (Eaocvtus). The conditions under which
the eggs of the gar-fish are naturally placed in British waters
have not been thoroughly ascertained, but Day mentions that
Mr. Dunn sent him in May 1881 a portion of a mackerel net to
which a number of the eggs of this fish were attached by means
of their filaments. These eggs had been shed by the fish when
captured, as frequently happens, in the mackerel net. Masses
of eggs held together by the tangling of such filaments have

94 MARKETABLE BRITISH MARINE FISHES CHAP.

been more than once described; they have been obtained in
the open Atlantic in tropical latitudes, and probably belong
to flying-fishes.

After fertilisation the egg-membrane in the eggs of all bony
fishes separates from the yolk mass within it, and at the same
time the germinal matter collects together and forms a mass
lying upon the yolk. The proportion which the mass of germinal
matter bears to that of the yolk varies considerably, in the
herring the former is nearly as large as the latter, but usually it
is very much smaller. In the eggs hitherto mentioned the yolk
consists of a number of globules of various sizes, held together
by a network of strands connected with the germinal mass. In
most cases there are also a few globules of a different kind,
consisting, in fact, of oily matter, at the surface of the yolk mass.
In consequence partly of the granular nature of the yolk and
partly of its separation into these numerous globules, adhesive
and heavy eggs are not very transparent, although generally
sufficiently so to allow of the embryo and internal parts of the
egg being seen to some extent in the living condition of the egg.
Herring eggs are rather more transparent than the majority of
adhesive eggs.

The third kind of eggs, those which float about in the sea, are
remarkable for their great transparency. It is difficult to dis-
tinguish them when present in small number in a bottle of clean
sea-water. This is due partly to the transparent character of
the yolk itself, partly to the fact that it is not disposed in a
number of separate globules, but usually forms a single undivided
mass surrounded by germinal matter in a thin layer on the out-
side. The character of a typical floating egg, such as that of
the cod or plaice, is shown in Fig. 45. All the parts of the egg
are clearly seen when it is examined in the living condition with
the microscope. After death and when preserved in the liquids
used by naturalists for the purpose the eggs become opaque.
The egg is made up of the membrane surrounding it, and the
mass of the egg proper, consisting of the germ, G, and the yolk,
Y. In such an egg there are no oil-globules and no divisions in
the yolk. The following are the fishes which are known to have
such eggs, the spawn of each of them having been examined by
naturalists—cod, haddock, whiting, bib, poor-cod, pollack, coal-
fish, plaice, flounder, dab, lemon sole or merry sole (PZ. m7cro-

IV EGGS AND LARV4 AND THEIR DEVELOPMENT 95

cephalus), witch or pole dab; all of which belong either to the
cod family or the flat-fish family. Of these eggs that of the
plaice is the largest, being about j4; inch in diameter, and that

FIG. 45. Fic 46. '

Fics. 45-48.—Diagrams of the chier types of floating marine fish-eggs. 45. Egg of
Plaice, Cod, &c., with undivided yolk. 46. Egg with simple yolk and single oil-
globule. 47. Egg of Sole with yolk beneath the germ divided into segments and
groups of minute oil-globules, 48, Egg of Pilchard, with yolk wholly divided,
and also a single oil-globule. G, germ; O G, oil-globule; Y, yolk; Y S, yolk
segments ; M, micropyle.

of the dab is the smallest, being less than 54 inch; the rest are
of sizes intermediate between these.

A large number of sea-fishes have eggs which differ from these
only in the presence of a single large oil-globule, situated not in

96 MARKETABLE BRITISH MARINE FISHES CHAP.

the interior but at the surface of the yolk (Fig. 46). When the
egg is first shed the oil-globule is movable, and when the
egg is placed on a glass slip under the microscope, and rolled
over, the globule always floats to the uppermost point. When
the embryo develops, however, the globule becomes fixed by the
germinal membrane in a position beneath the tail end of the
embryo. Sometimes three or four globules are present in the
egg when shed, which afterwards run together into one. Eggs
of this kind occur in a large number of different families. Many
species of the cod family and flat-fish family have them, namely
the rocklings (Aotella), the hake (Merluccius), the ling (olva),
the turbot and brill (Rombus), the topknots (Zeugopterus):
Among the spiny-finned fishes eggs of this kind have been dis-
covered to belong to the following: the mackerel, the gurnards,
the gray mullets, and the bass. The single oil-globule may be
present in conjunction with other conditions of the yolk.

The next complication to be considered affects the yolk,
and consists in the division of the part of it beneath the germ
into a layer of separate segments, while the rest is undivided.
The egg remains transparent, the partitions between the seg-
ments, composed of germinal matter, being very delicate. This
condition is known to occur in the common sole and other
kinds of sole among the flat-fish family. In the common sole
(Fig. 47) there are also a number of very minute oil-globules
which are arranged in irregularly shaped patches on the
surface of the yolk and give the egg to some extent a chalk-
white appearance when it is seen floating in a bottle of water.
The same condition occurs in the red mullet (fam. J/ud/:d@)
with a single large oil-globule in the yolk, and in the dragonet
goby family) with no oil-globule. It occurs also in an egg
supposed to belong to the American blue-fish, one of the same
family as our scad or horse-mackerel, in the egg of which
also it is probably present.

A. still further complication in the structure of the yolk
consists in the complete division of it into segments, which like
the condition last described may occur together with the presence
of an oil-globule or without. Floating eggs having this peculiarity
are scarcely less transparent than those which have a simple
yolk. It is found in the floating eggs of the sprat and pilchard :
in that of the sprat there is no oil-globule, in that of the

Iv EGGS AND LARVA! AND THEIR DEVELOPMENT 97

pilchard (Fig. 48) there is one. It occurs also in the egg of the
anchovy where there is no oil-globule, but the shape of this egg
is not round but sausage-like. The yolk is divided up in this
way also in certain floating eggs found at Naples in which there
were several oil-globules. These eggs may be considered with
confidence to belong to some fishes of the eel family, but which
particular kinds cannot be decided. It is not known that our
common eel, or the conger, have floating eggs.

It is interesting to notice that this last condition of the yolk
in floating eggs is the one which differs least from its condition
in attached heavy eggs, in which the yolk is always composed
of a number of separate globules. When the yolk has an outer
layer of separate segments it is in an intermediate condition, and
when it is not divided at all it is most altered from its condition
in fixed eggs, all the globules having run together into one large
globe.

One other peculiarity among floating eggs remains to be
mentioned. In the majority the space between the membrane
and the yolk is not large, the two are in contact at more than
one point. In a few, however, there is a much greater separation
between the two, so that the yolk is only about half as wide
across as the envelope which contains it. This is the case in
the egg of the pilchard (Fig. 48), in that of the long rough dab
among the flat-fishes, and probably also in the halibut.

There is scarcely any time of year or any part of the sea in
which floating eggs of some kind of fish cannot be found. Asa
rule, however, they are not visible from a boat or vessel, it is
necessary to collect them from the sea-water by means of a tow-
net, a simple apparatus in the shape of a bag with a ring of iron
or cane to keep the mouth open, and made of some kind of
cloth which will allow the water to strain through. There are
many substances which grow in the sea at the surface and near it
and which may be mistaken for fish-spawn. One of these is very
common, and usually very abundant in May and June, when in
calm weather it forms a visible scum on the surface. This
consists of little round grains, which under the microscope have
the appearance shown in Fig. 49. They belong to the lowest
and simplest classes of living things, and do not grow into any-
thing else. These grains have the power like many other marine
creatures of giving out light in the dark, and hence are called by

H

98 MARKETABLE BRITISH MARINE FISHES CHAP.

naturalists Noctiluca, or “night-light.” They are among the
principal causes of the phosphorescence of the sea. The scum
they form has usually a salmon-pink colour.

There are a few cases in which floating eggs instead of being
free and scattered are enclosed in large numbers in a single sheet
or mass of transparent jelly-like substance. The spawn of the
frog-fish or angler (Lophzus piscatorius),
for instance, was found by Prof. Alex.
Agassiz in America to form an im-
mense gelatinous band from two to
three feet broad and twenty-five to
thirty “feet long; Each ese “has “a
simple yolk and a single oil-globule,
and the band is formed of the eggs
of a single female sticking to one
another by the surfaces of their en-
closing membranes, the whole floating
Fic. 49.—A single globule free in the sea. The band or ribbon

Teas does not always float at the surface.

A portion of one was brought up ina

trawl in Mount’s Bay. In British waters it has been obtained

more than once. A quantity was once brought alive to the

Plymouth Laboratory, and it has been taken on the coast of
Scotland.

When the eggs of the bony fish are laid they have not been
fertilised, and the young fish have not begun to develop in them.
It has been explained that they come into contact with the male
generative substance in the water, and that one of the sperms
enters each egg through the micropyle and penetrates into the
germ. Before the egg is shed, when it is taken in a perfectly ripe
condition from the roe of the female, the membrane is in contact
with the contained substance, and the germinal matter forms a thin
layer all round the yolk. Whether the egg is fertilised or not,
certain changes take place init when it passes into the sea-water.
The membrane separates from the egg, and the germinal matter
collects into a mass on one side of the yolk. If the egg is not
fertilised no further changes occur in it; after a time it dies and
then putrefies. But if it is fertilised then a further process of
change goes on which converts the egg into a young fish. This
process is called the development of the fish. We may consider

Iv EGGS AND LARVA AND THEIR DEVELOPMENT 99

the life of the individual fish to commence the moment the egg
from which it arises is fertilised. This life consists of four distinct
stages or periods, of which the stage of development in the egg is
the first. The second stage commences after the fish is hatched.
At this time it is not like its parents, but very different, and is
usually called a larva. When a butterfly is first hatched it is a
caterpillar, a very different creature, and it has to go through a
transformation before it becomes a butterfly. The fish likewise
goes through a transformation, and the stage from hatching to
the completion of this transformation is the second period of its
life. The fish, however, after its transformation is still very small
and is not mature, its generative organs are not fully developed,
and therefore it does not begin to breed. The period from its
transformation to its maturity is the third period of its life, and
the fourth is that of the mature adult condition which is
terminated sooner or later by death.

The development of the egg of the bony fish differs from
that of the dog-fish or skate in many important matters, but there
is a general similarity between the two cases. In the bony fish
the duration of the process is much shorter, and the fish when
hatched is in a much less perfect condition. In fact in the case
of the dog-fish the first and second periods of life just defined
are not separate at all, but both included in the period of
development inside the egg-shell. This will be more fully
explained when the larva and its transformation are described.

The first step in the development of the bony fish is the
division of the mass of germinal matter into portions which remain
connected. It is by the continual division and growth of these
portions that the development of the fish is brought about. The
germinal matter is thus converted from a single mass of sub-
stance into a compound “tissue” from which the flesh and
organs of the embryo are formed. At first the tissue becomes
thin and forms what may be called the germ-skin, which spreads
out over the surface of the yolk until it completely encloses it.
But from about the centre of this germinal membrane to its
edge there is a thickened rod, which marks the back of the
young fish (Figs. 51, 52). The inner end of this rod, that which
is in the centre of the germinal membrane, is thicker than the
rest, and this part is the commencement of the fish’s head. At
the sides of this part appear two circles marking out the future

Hy 2

100 MARKETABLE BRITISH MARINE FISHES CHAP.

BOK PEF ARAL FARA
<>

Yk

Fics. 50-54.—The development of a buoyant marine fish-egg. 50. The fertilised
egg. 51. The same when the germ-skin has spread over half the yolk. 52.
The same when the germ-skin has nearly enveloped the yolk. 53. The same
when the embryo is advanced in development, and the tail has begun to grow
out. 54. The newly hatched larva. Yk, yolk; Ge, germ; G.S, germ-skin ;
N, nostril; Hd, head; Ht, heart; A, organ of hearing; E, eye; I, end
of intestine ; F M, fin-membrane,

vO

Iv EGGS. AND LARVA AND THEIR DEVELOPMENT IOI

eyes, and behind these a cavity on each side becomes the ear.
After the yolk has been completely enclosed by the germinal
membrane the little “embryo” still goes on growing at its
hinder end, and the result of this is the formation of the tail
(Fig. 53).

When the buoyant egg is left to itself in still water it always
floats with the germ or germ-skin downwards, because this is
heavier than the yolk. It should be noted that eggs do not
float because they have an oil-globule, since in a very large
number of floating eggs there is no separate oil-globule: they
float because they are lighter than sea-water, and they do not
float in fresh water, nor when they are unripe, nor when they
are dead.

The intestine, including under that term the greater part of
the food-pipe, namely gullet, stomach, and intestine, is formed as
a simple uncoiled tube. When development has reached this stage
it is easy to see that the yolk is now a large mass within the belly
of the little fish, which is greatly swollen by it. The thickened
rod is formed by, or becomes in the process of growth, the flesh
or muscles of the back of the little fish,and in the centre of these
is a slender rod around which the bones of the spine are after-
wards formed. There is no mouth. The fins arise as simple
flaps of skin without bones ; one of these in the middle line runs
along the back round the end of the tail, and forwards again
beneath the latter to the yolk. The breast fins appear as a
delicate flap on each side behind the head: the hinder fins do
not appear till later.

In the condition now described, in the case of buoyant
separate eggs, the little fish is hatched, that is to say the egg-
membrane bursts because it is no longer strong enough to resist
the growth and movement of the tail, and the little larva is set
free (Fig. 54). It is not difficult now to understand why the fish
when first hatched is called a larva, to mark its difference from
the fully developed fish. It has no mouth to feed with, no red
blood, and no bones. At first it floats upside down, because
there is still so much yolk, and the yolk is lighter than the body.
It goes on developing, nourishment as before being provided by
the yolk. On the newly hatched fish there are little stars of
colour, the tint and arrangement of which are different in
different species. These are the pigment-cells which are formed

102 MARKETABLE BRITISH MARINE FISHES CHAP.

in the skin and other parts, and which begin to appear some
time before hatching.

The time occupied in the development of the embryo in the
egg differs in different species, and in the same species differs
according to the temperature of the water in which the eggs are
contained, being quicker when the water is warmer, slower when
it is colder. It varies from three or four days to as many weeks
in the case of buoyant eggs, but is longer in the case of some of
the larger attached eggs.

The larve hatched from buoyant eggs are very small: one of
the largest, that of the plaice, is only } inch in length. The
larve hatched from attached, adhesive eggs are usually more
developed, and differ among themselves in size and degree
of development. Such eggs are in nearly all cases larger than
buoyant eggs, they have a larger yolk and a stronger egg-
membrane: the larva therefore remains within the latter for a
longer time, and does not leave it until it has reached a more
advanced condition. Usually the mouth is open and the jaws are
somewhat developed, and there is red blood inthe veins. Among
the most advanced fish at the time of hatching are the salmon
and trout, in which the longitudinal fin-membrane is already
separated into portions indicating the permanent fins. Fig. 55

Fic. 55.—Newly hatched young (larva) of the Common Black Goby.

shows the condition of the young of the black goby when first
hatched.

For some days the fish larva hatched from buoyant eggs, such
as the larva of the plaice or cod, continues to develop without
taking food, being nourished by the mass of yolk it still possesses.
The quantity of yolk continually diminishes ; the mouth appears
first as an opening on the lower side of the head, as it is in the
full-grown dog-fish, and then is carried to the end of the snout
by the growth of the jaws. The pigment in the body increases,

Iv EGGS AND LARVAD AND THEIR DEVELOPMENT 103

the eyes becoming quite black, though the rest of the body
remains very transparent. Black pigment in the eye is necessary
for vision. By the time the yolk is all gone, which is about four
or five days after hatching, the fin-membranes are somewhat
broader, but there are no fin-rays in them, nor any bones in the
body. The breast-fin is a rounded flap behind the head, the
second pair of side-fins are either small or not yet developed.

=

ISS SS = ———
qacrenraa CEC CC EL ERE EEE OT EE: 2
BET KSEE KKK K
BAA ti SMA £E
LE LE K Lf / i rs oe
Se

Fics. 56-58.—Three stages in the development of the Cod, showing the transforma-
tion of the larva into the perfect form. The larva represented in Fig. 56 is
a little over $ inch in length. At the stage of Fig. 57 the young fish is just

Bs

I inch long, at that shown in Fig. 58 it is about 1} inch.

At this stage the little fish begins to feed, and the particles it
takes are necessarily very small: the food consists of the minute
microscopic larve of shell-fish, worms, and other creatures with
which the sea teems. It is interesting to observe in the aquarium
that these little fish larvae, minute and delicate as they are, peck
at each particle of food in a deliberate and determined manner,
and that their food is not carried into them automatically. They
see each particle before they seize it, and snap at it by curving

104 MARKETABLE BRITISH MARINE FISHES CHAP.

the tail into the shape of an S, and then suddenly straightening
it. It is however very difficult to rear them completely in
confinement, and the successive stages of the various kinds of
fish have to be patiently and laboriously traced by comparing
specimens caught by fine nets in the sea.

The great and important change which takes place in the
larve after they begin to feed is the development of the bones
of the skeleton, connected with which is the formation of the
permanent fins. During this further development considerable
changes of form and habit take place, which are different in
different kinds of fish. The fin-rays are bony rods and develop
at the same time as the rest of the skeleton, and, the fish being
in most cases still very transparent when alive, the changes that
take place can be plainly seen.

The transformation of the larva with its continuous fin-
membrane, after the absorption of the yolk, into the young
cod with its three dorsal and two ventral fins is illustrated in
Figs. 56-58.

At the later stages of the transformation the little fish ceases
to be transparent, its flesh becomes thicker and denser, and the
skin becomes pigmented or silvery, and finally the scales, if
there are any, or other minor peculiarities of the perfect fish, are
developed. Tor the details of these changes in various species,
so far as they have been studied, reference must be made to the
figures and descriptions of particular fishes given in the second
part of this work. One or two special cases may be mentioned
here. The young herring in its intermediate stages is remark-
able for its great elongation and slender form, and its dorsal fin
is situated towards the tail, much further back than in the fully
developed fish. The most surprising transformation is that of the
flat-fishes (Figs. 59-62), the larvae of which swim upright and are
very similar to the larva of the cod or other fishes of the cod
family. When the fin-rays develop in these fishes their ex-
ceptional character is at once shown by the extension of the
dorsal and ventral fins along nearly the whole length of the
dorsal and ventral edges, and by the great breadth and thinness
which the body acquires. But during this part of the develop-
ment a most remarkable change occurs: the eyes are at first
opposite to each other, one on each side of the head, as in cod,
mackerel, or other fish, but when the fin-rays develop one of the

IV EGGS AND LARVA AND THEIR DEVELOPMENT 105

& >

BKC KS Peis 4
teri 2

ES

AN) : Ss
RKO

( fj Xx
\ Ki fi ay

WHE i) ] Ph

ARK ANY ss 1
pal Pt

Fics. 59-62.—Four stages in the transformation of the Flounder. Fig. 59, the larva,

=4°5 inch long, two days after hatching ; the yolk not yet all absorbed. Fig. 60,
the same six days after hatching ; the yolk all absorbed, and the mouth open ;
{5 inch in length. Fig. 61, specimen in a transition stage, with the left eye
near the edge of the head: length 34%; inch. Fig. 62, specimen in which the
transformation is nearly complete; the left eye on the edge of the head; same

length.

eyes, in plaice and others the left, in turbot and others the right,
moves out of its first position, rises first to the edge of the head,

106 MARKETABLE BRITISH MARINE FISHES CHAP. IV

and then passes on to the same side as the other eye. It is in
this way that these fishes come to have two eyes on the upper
side of the head, and the change takes place at about the time
when the little fish abandons the habit of swimming freely in
the water and takes to lying on the ground. The most im-
portant or final changes in the transformation of the larval fish
take place when it is between two and three months old, and
although the fish at three months old may still differ in certain
details from those which are older it is generally perfectly
recognisable as belonging to its particular kind.

Crab DER V
GROWTH, MIGRATIONS, FOOD AND HABITS

Growth.—A considerable amount of evidence has been collected
bearing upon the question of the growth of fishes. When the
fish has passed through the two stages already considered, the
development in the egg and the transformation into the perfect
form, it enters upon the third stage of its life, its adolescence,
which extends to the time when it becomes sexually mature and
begins to breed. It is important to know how large and how old
each kind of fish is when it spawns for the first time, and some
of the fundamental facts bearing on these questions are not
difficult to ascertain. It is obvious and certain that if every
individual fish that survived began to breed when it was a year
old, in other words spawned the year after it was hatched, then
there would be no immature fish in the spawning season, all
would be spawning or about to spawn. We know, however, that
this is not the case. If we take the trouble to find out the
condition of a large number of any kind of fish at the beginning
of the spawning season, we find that many of the larger indi-
viduals are spawning, but a large number of smaller can be
and are caught which show no signs of becoming ripe, which are
evidently immature. The youngest of these fish cannot be
much less than a year old, they must have been hatched
in a preceding spawning season, although some of them
may be more than one year old. This first fact is therefore
firmly established, that all the fish of one kind do not spawn
when a year old.

Before proceeding further with the subject of age it will be
convenient to consider that of size. A great deal of attention
has been drawn to the question of the sizes at which fishes of
different kinds begin to spawn, or, as it is usually expressed,

108 MARKETABLE BRITISH MARINE FISHES CHAP.

become mature. There has been a great agitation on the subject
of the destruction of immature fish, and various investigations
have been made with the object of ascertaining the size at which
maturity is attained. Different methods have been employed by
different investigators of the question. The simplest method,
which was first employed by Dr. Fulton, was to ascertain the
length of the smallest mature, z.c. ripe or nearly ripe, fish captured.
From the investigation in connection with which this method
was used very extensive information was obtained about the
depths and regions where fish of particular sizes were to be
found. But further investigation of the relation between size
and maturity was required. In his report on the Irish Survey
Mr. Holt gave the smallest sizes of ripe or nearly ripe males and
females, and in most cases the minimum was considerably lower
for the male, as might be supposed, considering that the average
size of the males is in) many ‘species. smaller But itmere gs
another question, namely, the largest size of the immature, for it
is found that some fish which are ripe are smaller than others
which show no signs of spawning. The solution of this question
involves a careful examination of the roe and milt for the purpose
of ascertaining how to make sure that a fish is immature, and out
of this another question has arisen, namely, may not a fish after
spawning return to a condition in which it is impossible to dis-
tinguish it from the immature ?

Provided the examination is made at a time of year when
there are no shotten fish of the species considered, when spawning
has scarcely begun, there can be no possibility of confusing
immature and shotten fish. In the plaice, the species to which
most attention has been given in this connection, the roe in its
immature state is small. It is triangular in shape, and extends
back only a short distance between the flesh and the bones
behind the belly cavity. A portion of its substance examined
with the microscope shows only minute transparent eggs which
have noyolkin them. Ina spent fish, one which has just finished
spawning, the roe is much larger and has thin flaccid walls. A
few ripe eggs are usually found in the cavity of the roe, and its
substance examined under the microscope shows besides trans-
parent eggs a few with yolk. But it is certain that in the plaice
the roe soon diminishes in size after spawning, and returns to a
condition in which it is difficult if not impossible to distinguish

V GROWTH, MIGRATIONS, FOOD AND HABITS 109

it from an immature roe. ‘The plaice and certain other fishes are
rapid spawners, and therefore shotten fish begin to be seen early
in the spawning season, and may be confused with immature
before the end of it. In the sole and other species which spawn
slowly there is little danger of confusion if the examination be
made in the earlier part of the spawning season.

At Grimsby it was found that the smallest mature females, of
plaice caught in the northern part of the North Sea, were 13
inches long, the largest immature not quite 18 inches. Of males
the smallest mature were 9 inches long with the exception of
one at 6 inches, and the largest immature not quite 16 inches.
At Plymouth the corresponding limits were 9 inches and 15
inches for female plaice, 9 inches and 12 inches for males. It is
thus evident that the plaice in the western part of the Channel
attain to maturity at a smaller size than in the North Sea, and
the fact that the average or usual sizes in the Channel are also
smaller indicates that the cause of the difference is not an earlier
or precocious maturity, but a permanent inferiority in size. It
has been shown that the smaller or Channel race of plaice
extends northwards from the Straits of Dover along the Dutch
coast, a considerable proportion of mature specimens being
found between 9 and 14 inches among the plaice caught on the
Brown Ridges, from thirty to fifty miles off the Dutch coast a
little tothe south of ithe Vexel, Oni the-other hand the small
plaice taken on the Continental coasts in the neighbourhood of
Heligoland do not belong to the smaller race, none of the females
being mature below the length of 13 inches.

The smallest mature female sole is 10} inches, the largest
immature 12 inches, the average 11 inches; the average for the
males being 9 or 10 inches. The haddock begins to spawn at
EM tow Inches: methes female sex, 1 inches in the: male: Whe
size of the cod at maturity is of course greater, namely, 22 to 35
inches in both sexes. It is unnecessary to give further particulars
here, they will be found in the separate histories of the different
species.

We have seen that the immature fish may be a year old, we
have now to consider whether some individuals spawn when
only one year while others are immature, or whether all or only
some spawn at two years. In the case of some fishes whose
movements are restricted, which live in estuaries or rivers, it is

I1O MARKETABLE BRITISH MARINE FISHES CHAP.

possible to fellow with considerable certainty the history and
srowth of the fry derived from a certain spawning season, and
so discover their condition at successive ages. But in most
cases it is found that after the first year the sizes vary so much
that the largest one year old cannot be distinguished with
certainty from the smallest two years old. Observations on fish
of known age in captivity are more certain, and must be instruc-
tive, although they are open to the objection that the growth
and history may be altered by the unnatural conditions. The
flounder however is a fish which bears confinement well, and an
experiment was made with a number of these at Plymouth.
The young flounders towards the end of their transformation
approach the shore and enter bays and estuaries, and in some
places are found in April and May in thousands in the pools left
by the ebb-tide. Between two hundred and three hundred of
these were obtained from Mevagissey in May 1890, and reared
in the Plymouth Aquarium. They were $ inch long and were
about two months old. In April 1891, having been fed regularly
but not very liberally, the largest was 7+ inches long, the smallest
not quite 2 inches. None of these specimens showed any signs
of spawning during the season of 1891. The difference in size
among them is remarkable enough, but we have good evidence
that the same variation occurs under natural conditions in the
sea. Plaice in small numbers from 1? to 34 inches long are
taken in January, February, and March in the Humber, and
flounders from 23 to 44 inches in April. These must have been
hatched the previous season, so that it is clear that growth in
the sea may be as slow as the slowest in the aquarium, and
may also be probably as rapid as the fastest in the latter. The
cause of the difference appears to be, first, competition for food,
secondly, the dependence of growth on the amount of food taken.
If each fish were fed separately the growth would probably be
nearly uniform. But where there are a large number, as in the sea
or the tank, and a limited supply of food, some get a start, and,
having once become a little larger, the more they surpass their
companions the better able they are to beat them in the com-
petition or search for food. It is reasonable to conclude from
these facts that no flounders spawn when one year of age, and
the evidence goes to show that the same holds true for other
flat-fishes and for sea-fishes generally.

Vv GROWTH, MIGRATIONS, FOOD AND HABITS Tele

The flounders above mentioned were kept a second year and
examined again in February and March 1892, when they were
two years old. There were 89 surviving, and they varied in length
from 3 inches to 103 inches. Twelve of them were ripe males 6:4
to 9:2 inches long, and four were ripe females 8°4 to 10°5 inches.
The rest showed no signs of spawning. It is remarkable that
the smallest ripe specimens were very nearly the same size as
the smallest ripe specimens taken at sea, namely, 6 inches for
males, 7 inches for females, a clear proof that the results were
not entirely altered in consequence of the confinement of the fish.
The largest immature fish was 9'7 inches long. It may be inferred
from this that some fish of a species may spawn for the first time
when two years old, while the majority are still immature.

At the end of three years the flounders which were immature
at two years old were examined, and were found to range from
5 to 114 inches, but they were not examined till May, when those
which had been ripe had spawned, and only two females were
still spawning. It is probable that few if any flat fishes are still
immature at three years of age.

Observations on fishes of different sizes taken at different
seasons, which are detailed in the accounts given of the separate
species, tend to show that the conclusions reached with regard
to flat fishes apply to the majority of other kinds. It has
already been mentioned that at the season when the mature
fish are spawning large numbers of smaller fish can be cap-
tured which show no signs of becoming ripe, which are
certainly sexually immature. Broadly speaking, these are one-
year-old and two-year-old fish, while a few of the spawners
are two years old, but the majority are three years and
upwards. On the other hand, where a large number of fish of
about the same size are taken together, it is often possible to
conclude that they are of the same age, and to estimate that age
with great probability. Thus in 18941 saw a very large number
of soles, plaice, lemon dabs, and common dabs taken by the
shrimp trawl in the Wallet off the coast of Essex. The soles
and lemon dabs were nearly all from 3 to 5 inches long, and as
the observation was made in June it could be inferred with
practical certainty that they were fish hatched in the previous
year. Again, the sardines, which form the object of a regular
summer fishery on the west coast of France, are certainly for

Di2 MARKETABLE BRITISH MARINE FISHES CHAP.

the most part one-year-old fish of the same species as the
pilchard.

There is reason to believe that many fish, chiefly those which
live near shore in shallow water, do not grow much in the coldest
season of winter, but exact observations on this question have
not been made. The conclusions above indicated concerning
sea-fishes agree closely with those reached long before by
observations and experiments on the salmon. The young salmon
remain in rivers the first year of their life as parr. At the second
spring when one year old some of them become silvery and
descend to the sea as smolts, returning the next autumn as grilse
which spawn. These grilse are therefore nearly two years old, but
many parr do not become smolts till they are two years old, and
therefore do not spawn until the third season after they were
hatched.

Migrations —The next points of interest concerning young fish
are the character of the localities in which they are found, their
distribution, as it is called, and their movements. The young of
certain kinds are found chiefly at the mouths of estuaries and
in very shallow water from the edge of the shore to ten fathoms.
The plaice is the most important of these. The young plaice
almost as soon as they have finished their transformation seek
the shore and the shallows, and in many places, where the shore
is flat and sandy, they are found in multitudes. Young flounders
also seek the shore, but are usually found in greater numbers in
the higher parts of estuaries than on the shore of the open sea.
Common dabs are found with the young plaice, and also soles,
turbot, and brill. Of round fishes the two kinds most abundant
in the shallows are cod and whiting, especially the latter. Large
numbers of all these kinds are taken in the nets employed for
the capture of shrimps. At Cleethorpes, at the mouth of the
Humber, shove-nets worked by hand by fishermen wading in the
water at low tide are used in shrimping. In these nets at the
end of April hundreds of small plaice, from 14 to 2} inches long,
are taken at one ebb-tide, and, considering what has been shown
by experiment to be the growth of the flounder, it is impossible
to doubt that these fish are the earliest young brood of the
season, hatched the previous January. Plaice of similar size are
also taken in June, and even later, but they become less numerous
towards the end of summer. Older fish, those of previous

Vv GROWTH, MIGRATIONS, FOOD AND HABITS 3

seasons, but immature, are also taken, but these are more
abundant in somewhat deeper water where they are captured
by the shrimp trawl worked froma boat. ‘The soles taken in the
shove-nets from April to June are the smallest of the brood of
the previous season ; they are 24 inches long and upwards, and
are taken only in small numbers. The newly transformed little
soles have been taken in the tide pools at Mevagissey in May,
and on the Newcome Sand off Lowestoft I have seen hundreds
of specimens taken in September which measured 2. inches to 24
inches long, and which were evidently three or four months old.
At Plymouth and other places young turbot are found in con-
siderable numbers swimming at the surface of the water in the
later stages of transformation in July and August, brill in May
and June. At these stages, before the lower as He reached its
final position, these fish are of considerable size, ? to 14 inches
in length, and differ from the corresponding neue of other flat-
fishes also in being opaque and coloured, and swimming con-
stantly at the surface, as they are able to do by means of the
large air-bladder which they possess at this period of their lives.
But during the next period of their growth, the first six months
after they have taken to the ground, they have not been taken in
numbers by naturalists, though in all probability living near the
margin of the sea. A few are taken in the shrimp nets in the
spring of the year after they are hatched, 34 inches long and
upwards ; these are about nine months old.

Wonene are taken in most localities where Sicini ne is
carried on, in enormous numbers in the autumn after they are
hatched, when they are from a little less than 3 inches to 5 inches
in length. But both whiting and cod for the first few months of
life, although living near the shore, are found chiefly near the
surface, the cod and also the haddock and whiting having the
habit at this stage of lurking beneath the bells of large jelly
fishes, and feeding on the surface crustacea.

In illustration of the comparative abundance of the different
kinds of young fishes taken on shrimping grounds, details of a
few catches are here given. In one shove-net at Cleethorpes in
one tide on April 25, 1892, were taken with four quarts of shrimps
the following fish :—

Baer of a WPS OOts cosa: see 14 to 4% inches.
ise alt Miles caecanemorinane 44 to 9 33
DaDSh ee ctarkenateee 3 eenonees ee

114 MARKETABLE BRITISH MARINE FISHES CHAP.

a Eee: eee ene Wo Boks waver ... 2 to 4% inches
WA ave eee ce 9 *
MINN OL setae ae seer esate. 24; 55
[S}alll lpaetponenesadactae Disa jalan len aivane eae RR LORA Same
SOLES” “an eeraceieveus 4 25 to 34 »
Smielistc nd ot en eee

A few Sand-eels, Pipe-fishes, Dragonets, Gobies, and Sticklebacks.

On September 27, 1893, with a 21-foot beam shrimp-trawl,
after a haul of 14 hours outside the mouth of the Mersey, with
32 quarts of shrimps were taken :—

WA SIONES Roget )
NoLtoy/ IAEWCS cooser
3) DYNO oadade .

169 Whiting ...
69 Codling ...,

all of small size, 7000 of the plaice
so small as to pass through the
meshes of an ordinary shrimp
riddle.

The older fish are found at somewhat greater depths and
distances from shore. As far as our present knowledge goes, it
appears that immature fish of the kinds here considered are taken
in considerable proportions on all grounds, and therefore at all
depths to which the species extend. Mr: Holt estimates that a box
of large North Sea plaice contains about 30 per cent. of immature
individuals. But the proportion below 13 inches is small, and
therefore we may conclude that there are very few one-year-
old fish, or fish in their second year, on the off-shore grounds.
The ordinary fair-sized fish are thus two years old and upwards.
The one-year-old fish are found on the shallower inshore grounds
where they are chiefly sought by small vessels which either fish
specially for them or take them with shrimps in shrimp trawls.
Such fish are chiefly found at depths between two and fifteen
fathoms. In certain places where the slope of the ground sea-
wards is very gradual the small fish are in great abundance, and
the capture of them in very large numbers has drawn attention
to these grounds, so that they have been carefully studied. The
most widely known instance of this is afforded by the eastern
grounds of the North Sea, extending along the Dutch and
German coasts from the Texelto the Horn Reef. Examination
of these shallow grounds north of Heligoland in 1895, between
the depths of seven and thirteen fathoms, showed that the fish
taken by the deep-sea trawl on them were as follows. The
plaice ranged from 5 inches to 16 inches in length, so that the
proportion of mature fish was small. Of course they were not

Vv GROWTH, MIGRATIONS, FOOD AND HABITS 1 ES

all one-year-old fish between these sizes, but one-year-old and two-
year-old mixed. A considerable number of mature soles were
taken, but none under nine inches in length. The one-year-old
soles doubtless escape through the meshes of the large trawl. The
smallest brill taken was 8 inches long, the smallest turbot 84
inches, but there were a considerable number of large mature fish
of these two kinds, as wellas many immature. It would appear
that the yearling turbot and brill are for the most part nearer
shore than the grounds here in question. Haddocks were scarce
on these grounds, dabs of all sizes were abundant. An im-
portant fact is that considerable numbers of large mature
specimens of the latchet or tub (Zrzgla hirundo), a species of
eurnard chiefly found in southern waters, and common in the
English Channel, were taken. This was in June. There were
also a few grey gurnard and red gurnard, and numerous
whiting.

The flat-fishes whose young are found in deeper water are
the lemon dab (“lemon sole”), witch, megrim, long rough dab,
and thickback. The newly transformed lemon dabs seem to
seek water rather deeper than that inhabited by their parents. In
the Irish Survey only two less than 2 inches long were obtained,
and they were taken at 60 and 80 fathoms. The yearling lemon
dabs have however been found in shallow water, in the Wallet, as
already mentioned, and in the estuary of the Humber. Specimens
of the witch under 2 inches long were taken on the west coast of
Ireland at from 70 to 80 fathoms, and of the megrim at the
same depth. The long rough dab also at less than 2 inches was
taken at 50 to 80 fathoms.

Among round fishes haddock for the first year of their life
are not found in shallow water or very near shore. In July and
August Mr. Holt obtained a considerable number from 3 to 5
inches long on the Great Fisher Bank and in more southern
parts of the North Sea at depths of 16 to 30 fathoms. Three
inches appears to be the size at which the haddock begins to
feed on or near the bottom. Off the east coast of Scotland
Dr. Fulton found young haddock most abundant at 25 to 30
fathoms.

A more precise and comprehensive method of investigating the
history of fishes in their natural condition has recently been
suggested and applied by Dr. Petersen in Denmark. This

2,

116 MARKETABLE BRITISH MARINE FISHES CHAP.

method consists in measuring each individual of all the fish that
can be collected of a particular species, taking care to collect
samples of all sizes and from every different region it inhabits
at different stages of its growth. It will then be found that the
individuals group themselves in largest numbers about certain
lengths, while there are comparatively fewer of the intermediate
lengths. The groups of which the members thus approximate
to certain lengths are the products of successive spawning
seasons, and when the lengths and numbers are registered in the
form of curves the whole growth and development of the species
is exhibited. We have seen that the shoals of young fish
derived from the preceding season can often be recognised, and
also sometimes those which are in their second year. The
statistical method not only gives more precise information about
these, but enables us to distinguish the two-year-old and three-
year-old fish. When the condition of the fish with regard to
spawning is also registered, we see at what age and size maturity
is attained. The full application of this method is work for the
future, since it obviously involves considerable labour: to apply
it properly the collections for a single investigation ought to be
made within a brief period, as otherwise the measurements are
not comparable.

The migrations of adult fishes depend principally on three
causes or conditions—the development of the breeding
organs, the need’ for food, and the “season jor) them year
most fishes have their customary breeding grounds, feeding
grounds, and winter and summer quarters. With regard to the
herrings their visits to their spawning beds are very regular, the
same beds are visited annually for centuries or longer. But
although the movements and positions of the young at successive
stages have been followed with some success we cannot say with
much certainty where are the adults in the intervals between the
spawning periods. They are taken occasionally in small numbers
in these intervals, and in all probability retire to some distance
from land. If we consider the multitudes of herrings in the North
Sea in summer from July to November, it seems certain that
they cannot remain there from November to July without being
caught ; the winter herring are not the same, and we must there-

1 See Fourth Report of the Danish Biological Station, 1893.

Vv GROWTH, MIGRATIONS, FOOD AND HABITS Wan

fore conclude that the summer fish retreat towards the open
ocean. .

Mackerel and pilchards, which have no fixed spawning
grounds, do not make such extensive migrations, and are not
entirely beyond the reach of observation at any time of the year.
The mackerel in the Channel comes nearer the coast in summer
and is found spawning in May and June up to about five or ten
miles from land, but it does not enter bays in pursuit of young
sprats until after the spawning season in August and September.
In winter it retires from the coast. The pilchard, on the other
hand, retires from the coast at the spawning season, and is
found, when spawning, chiefly from thirty to fifty miles off. It
remains on the coast in winter.

An interesting subject, whose study is far from having been
exhausted, is the extension of southern or Channel fish along the
Continental coast into the North Sea. The anchovy is found in
considerable numbers in the Channel in winter from October or
November onwards. Although a regular fishery for it has not
yet been established on the English coast, it is taken regularly
in small numbers in drift nets or seines used for sprats, pilchards,
or mackerel on the coasts of Devon and Cornwall, and has been
in some years taken in considerable numbers in the Straits of
Dover in November. There is a regular fishery for it annually
in the Zuyder Zee and the Schelde, in May, June, and July.
It seems certain, therefore, that the anchovies, which in the
Dutch estuaries spawn in summer, retreat in winter through the
English Channel. In asomewhat similar way the mackerel enters
the narrower southern part of the North Sea through the Straits
of Dover in summer, and supplies a regular annual fishery off
the coasts of Norfolk and Suffolk. Off Lowestoft mackerel are
caught in May and June, and again in September, October, and
the beginning of November. Perhaps in the intervening months,
July and August, they go further north along the Continental
coast, and the autumn fishing corresponds to their returning
migration. Thirdly, the tub or latchet (Z77zgla hirundo), which
is a constant inhabitant off Plymouth, is taken on the eastern
erounds of the North Sea near Heligoland in June, and off
the Dutch coast opposite Lowestoft in September. It probably
is found in these regions all the summer, but I am not certain
whether it retreats to the Channel in winter.

118 MARKETABLE BRITISH MARINE FISHES CHAP.

Some ground fishes come nearer the coast to spawn while
others go further off. Cod are among the former; they spawn
in March and April, and the adults when feeding are for the
most part on deeper and more distant grounds at other seasons
of the year. Haddock and whiting do not make any obvious
migration at the spawning season; the haddock is found in
spawning condition from 30 to 150 fathoms, the whiting from 10
to 40. With regard to the shallow water flat-fishes, we have
seen that mature soles, turbot, and brill are found in summer
time in quite shallow water near the coast with the immature.
Soles betake themselves to deeper water in winter, and the same
thing has been observed of turbot and brill, but the larger adult
plaice remain always for the most part in the deeper water.

food and Habits—Among quadrupeds and birds there are
some which live entirely on a vegetarian diet, and others which
take their vegetable nourishment at second hand by preying upon
the herbivorous species. Among fishes there are very few kinds
which take any vegetable food at all. There is however an in-
teresting distinction between those which prey upon other fishes
and those which feed upon the lower orders of marine creatures.
But the division is by no means complete ; there are some fishes
which feed only upon other fishes, and some which do not devour
other fishes at all, but there are many which habitually take a
mixed diet, including both fish and lower animals. Some of the
fishes which prey upon the other fishes, if not all, take cuttle-fishes
or squid when they can get them. The angler lives entirely upon
fish ; the ling, almost entirely ; the conger, almost entirely ; hake
and pollock very rarely eat anything else ; whiting, largely ; the
cod, largely; the coal fish, largely; the dory, entirely; the
turbot, brill,and megrim, almost entirely. Other species in whose
stomachs other fish are found are the gurnards, the haddock,
long rough dab, and also lemon dab, sole, plaice, and common
dab. Among the dog-fishes and rays the picked or spiny dog-
fish lives entirely on fish, and the other kinds take fish to some
extent, except the small spotted dog-fish and the thornback.
The mackerel and the shads also prey upon smaller fishes. The
habits and modes of obtaining their food are as varied among
these predaceous forms as the habits of their victims to which
they are adapted. It is necessary, therefore, to consider the
habits of the victims first.

V GROWTH, MIGRATIONS, FOOD AND HABITS 119

The habits of the fishes which feed upon the lower animals
again are necessarily related and adapted to the mode of life of
these lower animals. The principal different kinds of marine
creatures which are not fishes are the Echinoderms, that is to
say, starfishes, sea-urchins and the like, Worms, Molluscs, and
Crustaceans. In all these classes most of the larger kinds live
on the sea-bottom, and have no powers of swimming, or very
insignificant powers. The most important exception to this
general rule is formed by the squids and cuttle-fishes, which are
swimming molluscs with reduced shells. The echinoderms, or
spiny-skinned animals, usually remain exposed on the surface of
the ground, but many of the worms, molluscs, and crustaceans
conceal themselves as much as possible either by burrowing in
soft ground, by building tubes or coverings, or by hiding among
stones, rocks, or sea-weed. Many of these animals, chiefly
among the worms and molluscs, are quite stationary; in the
large and abundant class of bivalve molluscs such as the mussel
and oyster, scallop, razor-shell, &c., the power of movement is
usually extremely limited. All these classes of animals, which
inhabit the bottom of the sea in very great numbers, form the
food of bottom fishes. The fishes continually seeking these
creatures on the ground beneath the water may be compared to
the flocks of starlings and other birds which feed upon the
worms and insects, snails and slugs on land. Different fishes
feed principally on different classes of lower animals, but no
kind of fish confines itself exclusively to one class of prey. Thus
the haddock and cod feed principally on crustacea, but devour
also large numbers of molluscs. The gray gurnard also feeds
principally on crustacea, and likewise the large-mouthed long
rough dab. The principal food of the plaice is composed of
molluscs and worms, the former usually predominating : the sole
and lemon dab live chiefly on a diet of worms. In each class of
the lower animals there are certain common and abundant forms
which are of chief importance as food for the valuable fishes.
Among the crustacea the hermit-crabs are devoured in very large
numbers. These crabs, as is well known, live in the empty
shells of molluscs. There are several species of them differing
im size, the largest, the? common hermit-crab) (Pic. 63) is
usually found in shells of the common whelk. The shells are
not swallowed by the fish, but the crab is dragged out of its

120 MARKETABLE BRITISH MARINE FISHES CHAP.

The common brown shrimp, and the
The swimming crabs are

house before being eaten.
pink shrimp are also largely eaten.

Fic. 63.—The Common Hermit Crab, lying beside the whelk-shell which it
inhabits.

Fic. 64.—A Swimming Crab.

distinguished by the flattening of the hinder pair of legs which
_ they use as paddles, and are thus enabled to sustain themselves
for a short time in the water. These are very common in

Vv GROWTH, MIGRATIONS, FOOD AND HABITS uA

British seas, and are largely devoured by cod, haddock, and
gurnards. One of the commonest kinds is represented in Fig.
64. Fig. 65 shows an example of another class of Crustacea,
called the Amphipods, to which the common sand-hoppers
belong. They are generally smaller than the crabs. -The
species figured burrows in soft ground and is common on all
our coasts. It is frequently found in the stomachs of haddocks,
gurnards, long rough dabs, common dabs, witches, and plaice.

Fic. 65.—Ampelisca, a common marine Amphipod.

In Figs. 66-70 are represented the forms of some of the
molluscs most commonly found in the stomachs of fishes.
Razor-shells or So/en, of which there are several species, are
largely eaten by plaice in the Firth of Forth and the North Sea.
The smaller specimens are swallowed entire, the shell which is
thin being crushed by the teeth in the throat of the fish, but
often the stomach is found to contain only the fleshy parts of
the shell-fish, commonly called the feet. The Se/en lives in a
vertical position in a hole which it burrows in the sand by means
of its “foot,’ and the latter is therefore turned towards the
bottom of the hole. Yet the plaice is able to drag the shell-fish
from its burrow, and to seize its “foot” and tear it out of the
shell. Figs. 66, 67 represent two different species of razor-shell,
the straight form which is represented as seen from the ventral
surface, with the lower edges of the shell separated to show the
foot, being Solen stliqua, the curved form Solenx ensis. The

122 MARKETABLE BRITISH MARINE FISHES CHAP.

Fics. 66—70.—Molluses which commonly serve as food
for fishes. 66. Soler seligua, a Razor-shell. 67.
Solen ensts, another kind of Razor-shell. 68.
Mactra subtruncata, a common bivalve. 69. Scvob2-
cularta, a smaller kind of bivalve. 70. The
common Squid.

former grows to a length of 8 inches, the
latter to 32 inches. I found that the
small plaice landed at Grimsby in March
from grounds off the Sylt Island on the
German coast had been feeding almost
entirely on So/ex, and it also forms a
considerable part of the food supply of
the same fish in the Firth of Forth. The same shell-fish is

Vv GROWTH, MIGRATIONS, FOOD AND HABITS EZ

also found occasionally in the stomachs of other flat-fishes,
namely, common dabs, long rough dabs, and even some-
times in lemon dabs. The bivalve represented in Fig. 68
(Mactra subtruncata) is eaten by plaice on the Dogger
Bank, and in the Firth of Forth, and doubtless in other
localities. The small shell-fish shown in Fig. 69 (Scrodz-
cularia), of which there are two or three species, forms
a large proportion of the food of the plaice in certain
localities, such as the Firth of Forth and the Irish Sea. It
is also eaten by other flat-fishes, and very largely by the
haddock. The common squid (Fig. 70) is a favourite food
of the cod, conger, spiny dog-fish, turbot, brill, ling, and other
fishes.

We next come to the Annelids or Worms, now usually and
more precisely named Chaetopods. The common lug-worm re-
presented in Fig. 71 is well-known from the fact that it inhabits
flat muddy shores between tide marks all round our coasts in
countless multitudes, but it lives also beyond low-water mark
where the ground is sufficiently’soft. Fig. 72 represents a creature
commonly known as the sea-mouse, but to which naturalists
have given the name of the Greek goddess of love and beauty,
Aphrodite. Notwithstanding its unusual shape and appearance,
it is one of the bristle-bearing worms, consisting like the rest of
a series of similar segments; but the boundaries of these
segments are concealed by a sheet of felted bristles which covers
the back. Its beauty consists, not in its rotundity of form or
curved outline, but in the iridescent colours of the delicate silky
bristles on its sides. In Fig. 73 is shown the appearance of one
of the commonest of the numerous species of /Verezs which live
under and between stones, or burrow in soft ground. All these
forms, as well as numerous other species of worms, many of
which live in fixed tubes of their own manufacture, are largely
eaten by plaice, sole, lemon dab, and other flat-fishes. Aphrodite
is also eaten by cod and haddock, and by the thornback ray,
and the spotted dog-fishes.

Among Echinoderms the forms most largely eaten by fishes
are those known as sand-stars and brittle-stars. Two of the
species most constantly devoured are represented in Figs. 74, 75.
The sand-star (Ophiura albida), is distinguished by the stiffness
of its arms, and the minuteness of the spines which they bear.

CHAP.

FISHES

MARINE

MARKETABLE BRITISH

The

rie
73. LVerets pelagica.

ly serve as food for fishes.

The Sea-mouse, Aphrodite.

=
=)
e}
a
S
=}
=)
ie}
Oo
a
ao
1S)
or
G
=
S
wn
anne
aN
= Ir
ie)
=
ane
os
(al ts
Gy
ed
eS
ae
m on
iS
les
ze)

7

==
Common I

FIGs.

Vv GROWTH, MIGRATIONS, FOOD AND HABITS 25

In the other form (Amphiura filiformis), the arms are longer,
more flexible, and bear longer spines. In othersagain the spines
are much longer and the arms thicker. These are found in the

Fic. 74.—A Sand-star (Ophiura albida).
Fic. 75—-A Brittle-star (Amphiura fileformts).

stomachs of plaice, sole, lemon dab, common dab, long rough dab
witch and haddock, but in the case of the plaice, lemon dab, and
witch, only in a small percentage of individuals ; they are most
regularly eaten and in greatest numbers by the haddock and

126 MARKETABLE BRITISH MARINE FISHES CHAP.

long rough dab. Common star-fishes are occasionally swallowed
by the haddock and long rough dab but, as might be expected,
the strong-spined sea-urchins do not serve as food for fishes
to any great extent; some of the softer-shelled forms with
weaker spines (Spatangus, Amphidotus) are however occasion-
ally eaten.

But there are fishes which feed neither on the ground animals
nor on other fishes, namely, those which feed on the lower animals
that swim in the water. In other words, the water has a popu-
lation of lower animals as well as the ground under the water,
and this population supports different kinds of fishes. The swim-
ming animals now to be considered are all small, very small, or
extremely minute, but they make up by their numbers for their
small size, and consequently the amount of substance contained
suspended in the water of the sea is enormous, and forms a
very large supply of available food. This floating population of
the water consists partly of permanent elements, partly of
temporary, that is to say, partly of animals which live their
whole lives in this condition, partly of the minute young (larve)
of nearly all the animals that in their adult condition live on the
bottom. The chief class among the permanent inhabitants is
that of the copepods, a particular division of the crustaceans,
ranging in size from 4 inch downwards. These animals are
constantly and everywhere abundant, and their bodies are rich
in oil and extremely nutritious. With these there are swarms
of the larve of larger crustaceans, worms, molluscs, and echino-
derms, which succeed one another according to the breeding
seasons of their parents,and are most abundant insummer. All
these together form the food of the teeming shoals of surface
or mid-water fish, namely, the herring, pilchard, and sprat.
The mackerel feeds by preference on young sprats or other
young fish which swim near the surface, but appears to
depend on the same kind of food as the herring at certain
times.

Some examples of the numerous different minute forms
which live suspended in the water of the sea are represented in
Figs. 76-81. The copepod, shown in Fig. 76, is one of the
largest and most abundant in the North Sea and on other parts
of our coasts. Fig. 80 represents a stage in the development of
a common swimming crab (Portunus). The actual length of a

127

GROWTH, MIGRATIONS, FOOD AND HABITS

% JO BAIVT ‘O08
SUTULIOJ-aqn} vB JO &

‘ulyomn-vag vB Jo valeTy ‘6

Arey LL

‘podadog wowutos vB ‘s7227

‘(sogt4p wn2jpp.1a7) wstuesio ayt-yurfd y ‘1g “qvag SULUWIMG

‘(satoads ayeryouraqipnu) sn][OP, SSey-]]aYs B Jo vaiwy] “gL *(asopornaT) WACOM
sapuiuy snunjpvy ‘OL

‘speuttue ordepod oynurut jo saduexa suiogS—"Ig-9f “SOI

128 MARKETABLE BRITISH MARINE FISHES CHAP.

larva of this kind would be about 3 inch. It is remarkable for
the length of the spines which project forwards and backwards
from the head region, and for the length and size of the tail,
which in the fully developed crab is rudimentary. Fig. 77 repre-
sents a larva of one of the tube-inhabiting worms ; among the
features by which this form is distinguished is the great length
of its bristles. Fig. 78 shows the structure and appearance of a
mollusc larva; in this case the larva of one of the shell-less or
nudibranchiate forms. The larva however is provided with a
shell into which it can withdraw itself, and with an operculum
with which it can close the aperture. It sustains and propels
itself by means of the long vibratory processes or cilia on the
edge of the lobes which protrude from the shell. In Fig.
79 is represented the larva of one of the echinoderm class,
namely a sea-urchin. One chief peculiarity of this larva is
the presence of eight very long arm-like projections, each of
which is supported by a calcified rod. It will be understood
that to the unaided vision such creatures as those figured
appear in a glass vessel of sea-water merely as moving
specks, and that the figures represent them as seen under
the microscope.

A complete account of the animals which serve as food for
fishes would embrace nearly the whole of marine zoology, and
indeed a thorough knowledge of the subject including the par-
ticular forms on which each kind of fish depends in its early
stages, and in the different regions it visits, and the mutual
dependence of the various animals in the sea is not yet available,
but has to be obtained by further investigation of the most
minute and extensive kind. One more interesting form however
may be mentioned here.

Its shape and appearance are represented in Fig. 82. It
belongs to the same division of crustacea as the opossum shrimps,
which differ from the common shrimp in having usually eight
pairs of long anterior (thoracic) legs, each of which forks into
two branches. This particular species and its nearest relations
have the remarkable power of giving out light, a property which
does not belong to the whole body but is localised in ten special
rounded organs, four in a single row on the abdomen, two pairs
on the bases of the anterior limbs, and one on each eye-stalk.

Vv GROWTH, MIGRATIONS, FOOD AND HABITS 129

In its younger and smaller stage this luminous shrimp has been
taken in numbers at the surface of the sea, in the North Sea, in
the Firth of Clyde, and off the coast of Cornwall. But in the
adult condition it has only been taken at considerable depths ;
it is then about 13 inches long. It does not, however, when adult
crawl upon the bottom ; it is a restless swimmer and requires no
support, but is only found near the bottom. This animal is a
constant inhabitant of certain deep gullies in the Firth of Clyde,
where the depth is about 70 fathoms, and where it can always be
captured in some numbers by towing a shrimp trawl at consider-
able speed. Recent observations have shown that Loch Fyne

pe GON ea y
S Tr Ne (« (

Yn
yh

N SS

Fic. $2.—A luminous Shrimp (WVyctzphanes) ; after G. O. Sars.

herring feed largely on this crustacean, a fact which proves that
herring may descend to considerable depths.

It is a well-known story that some Hindoo religion taught
that the world rested upon the back of a great elephant, and
the elephant stood on the back of a huge tortoise, and that when
an inquiring student asked what the tortoise stood on, he was
severely punished for his irreverent audacity. In the case of
fishes we have seen that some feed on other fishes, and these on
lower animals, and now follows the question—What do the lower
animals feed on? Fishermen are apt to solve such difficulties by
the statement that these creatures Jive on suction, which is in
many cases perfectly true ; but what is the substance sucked in ?
We know that the original source of all food is the vegetable
kingdom, which is able to build up its substance from the air

K

130 ; MARKETABLE BRITISH MARINE FISHES CHAP.

and soil and water with the help of the sunlight. So it is in
the sea. Creatures may prey upon other creatures, but in the
last result they depend upon the vegetable kingdom. The
elucidation in detail of the mode in which this is effected still
offers an interesting field of study. We know that large numbers
of univalve shell-fish, such as the periwinkle, graze on the fields
of sea-weed which fringe the shores, and that these shell-fish are
eaten by fishes. But it is certain that the chief supply of plant
food in the sea consists of very minute microscopic plants. These
exist constantly in a detached suspended form in the water, and
alsc on the bottom. Then there are exceedingly minute micro-
scopic forms of animal nature that live upon the minute plant-
forms. All the bivalve molluscs, which form no inconsiderable
portion of the food of fishes, live entirely by the “suction” of
these exceedingly minute animals and plants; they are able to
draw a current of water constantly through the cavity within the
shells, and there this food-dust is strained out and passed into
their stomachs. In the upper waters the microscopic plants form
the food-basis of all the population.

The variety of form in these plants is remarkable, and their
abundance in individuals often so great as to render the water
turbid and to colour large areas of the sea. One common form
in British seas is a small sphere of a bright green colour. The
diatoms are distinguished by their yellowish brown colour, and
their indestructible siliceous (flinty) coating. There is another
tribe of organisms which appear to live like plants, but have often
been placed in the animal kingdom. One of the most characteristic
of these is shown in Fig. 81. Unlike those already mentioned,
these forms are provided with long vibratile processes or flagella,
although these are only seen under favourable conditions.
Scarcely any gathering of floating minute organisms can be
obtained off our coast without including some specimens of the
organism figured (Ceratium tripos).

Every kind of fish has its own special way of obtaining its
food, to which its habits, senses, and structure are adapted, and
the adaptation is often most curious and interesting. The herring,
sprat, and pilchard, depending chiefly on minute creatures in
small numbers, do not have much need for teeth, and accordingly
in them the teeth are small or absent. In these fishes, and in
certain others, e.g. the basking shark, as mentioned in Chapter II.,

Vv GROWTH, MIGRATIONS, FOOD AND HABITS 130

the length and proximity to one another of the gill-rakers con-
stitute a special apparatus for straining minute organisms from
the sea-water. The gill-rakers are stiff horny rods projecting
forwards from the inner and front edges of the gill-bars, and
in fishes which feed on large animals they are short and far
apart, so that the gill-apertures are wide and unobstructed.
But in the herring, shad, pilchard, &c., the projections are long
and close-set like the teeth of a comb, and thus fill up the
whole of the gill-apertures with an efficient straining apparatus
(Fig. 83). The fish takes gulps of the water containing crowds
of copepods, &c., and passes the water through its gill-rakers

— ED: =)
SS) YS Vf

ie “fl S f/f
Y=),

in d

Fic, 83.—The gill-bars and gill-rakers of the Herring, the gill-filaments which are
attached to the outer sides of the gill-bars having been removed.

The way in which the sides of the upper jaw are brought to
the front of the gape when the mouth is open, is also probably
of some advantage in the process of feeding. The mackerel, on
the other hand, pursues separately the small fish on which it
preys, hunting them by sight; its activity and speed are its
special adaptations in addition to its tweezer-like jaws. The fact
that mackerel are so easily caught with artificial bait having a
shining surface and moving through the water, and that they
will bite at almost anything attached to the hook provided that it
is moving, shows clearly how they are accustomed to snap at
small fish and are guided by their eyes, not by smell, touch, or
taste. Fish that thus trust to their sight naturally feed in the
daytime, and fishing for them with hook and line must be carried

KGRZ

132 MARKETABLE BRITISH MARINE FISHES CHAP.

on in the daytime. The whiting is another instance. An upper
jaw longer than the lower is generally found in fishes which feed
on the ground, and in the fishes of the cod family a barbel on
the chin is associated with this condition. The barbel signifies
that the sense of touch is called to the aid of that of sight and
smell in finding prey, and it carries with it the possibility of
feeding in the dark. Thus fishes with barbels may be chiefly
nocturnal in their habits ; this is the case with the ling and the
rocklings, the latter having several barbels. To watch a rockling
hunting in the aquarium reminds one forcibly of a dog following
a scent, and it is a matter of observation that they remain con-
cealed in daytime, except when induced to come out by the
presence of food, if they are hungry, and that they move about
freely at night. The fishes of the cod family which feed in
the upper waters have usually the lower jaw longer than the
upper, and no barbel; as for instance the pollack, but in the
hake the jaws are equal in length.

Among the flat-fishes there are some which feed on other
fishes, and others which feed on lower animals. The correspond-
ing difference in the jaws is interesting; the fish-eating forms
have the mouth large, the jaws strong, and equal on the two
sides of the body, with sharp teeth; as in the turbot, brill,
megrim, long rough dab, and halibut. In the plaice, dab, lemon
dab, and sole, on the other hand, the mouth is small, and the
jaws and teeth very feeble on the upper side of the head, strong
on the lower side. These fish bite with the lower corner of the
mouth. The fish-eating flat-fishes also exemplify the process of
obtaining prey by lying in ambush, concealed, instead of pursu-
ing and overtaking it ; they lie partly or wholly buried in sand or
cravel, with their changeable colouring where it is exposed
closely resembling the appearance of the surrounding ground,
and when other fish come near enough they rise suddenly and
seize them. The other flat-fishes are also well concealed, but
the result in their case is escape from enemies, not deception of
victims.

The sole is one of the most retiring of fish ; its burrowing
habits and power of changing its colour to resemble the ground
make it almost or quite invisible, and it seldom moves or un-
covers itself except at night. In the aquarium this is constantly
observed, although it will when hungry feed in the daytime. It

Vv GROWTH, MIGRATIONS, FOOD AND HABITS Ba

is provided with special organs of touch on the lower side of its
head, and also has an acute power of smell. It hunts for worms
or shrimps by tapping the ground gently with the side of its
head. The eyes are only of use to see enemies above it, and
although in the aquarium it acquires in time the habit of rising
from the ground and taking worms as they fall from above, it
finds difficulty in seizing them before they reach the bottom.
Yet with all this provision for concealment, of no use in obtain-
ing food, we do not know at present that it is a much persecuted
fish. Future examination of the food of predaceous forms,
perhaps of skate and angel rays, may show that the sole has as
much to fear as its concealment would indicate; it has been
found in the stomach of the angler.

The plaice, although it buries itself at times, feeds principally
in the daytime and on shell-fish. It has a special crushing mill
for these in its throat. Nearly all fishes have teeth in the throat
on certain bones belonging to the gill apparatus, and these teeth
are usually sharp, but in the plaice they are broad and rounded,
and crush shells with great ease. Similar teeth are found in the
jaws of the cat-fish, which feeds on crustaceans and shell-fish.

The mode of hunting of the angler and John dory have not
yet been mentioned. The former has special provision for con-
cealment and has huge jaws, the lower of which projects beyond
the upper. The spines of the first dorsal fin are separate, and
can be raised into an upright position on the top of the head, the
first having a tag of membrane at the end. The fish lies at the
bottom, and other fishes appear to be attracted by this tentacle
and fall a prey to the angler. The dory swims upright in mid
water, and its body is extremely thin from side to side, so thin
that when it is directed towards another fish it does not attract
notice or create alarm, and the dory is able gradually to approach
within striking distance. A fuller account of these two fishes is
given in their special histories.

Among the dog-fishes and skates and rays there are similar
differences in the habits and food. The spiny dog-fish is a bold
strong swimmer which pursues and devours weaker fishes in the
daytime ; it persecutes herrings, sprats, mackerel, and whiting, and
lives in shoals which are sometimes so large that they seriously
interfere with drift-net fishing. The spotted dog-fishes, on the
other hand, are nocturnal, and feed chiefly on the lower animals

134 MARKETABLE BRITISH MARINE FISHES CHAP. V

of the ground, especially crustacea. In the aquarium these fish
lie still and apparently asleep or half asleep in the daytime and
move about at night. They hunt by smell. It seems somewhat
surprising that the common or gray skate should feed largely on
fish. It is easy to understand that it can feed on bottom fishes,
and these do form great part of its food, but pollack, whiting,
and mackerel are also found in its stomach, although its shape
would appear to be eminently unsuited to their capture.

The food of fishes in their young stages is necessarily different
from that of the adults. Mention has already been made of the
minute living particles swallowed by the delicate newly-hatched
larvee of bony fishes when living in the open or surface waters. In
a successful endeavour to rear larval herring at Kiel it was found
that at first they ate the larve of small molluscs, and when they
grew a little larger, began to take copepods which soon formed
their entire food. Copepods also form a large proportion of the
food of other young fishes. On the Lancashire coast young
plaice § inch to 24 inches long were found to be feeding principally
on minute crustacea, and about half of the crustaceans in the
stomachs were copepods; the others were young shrimps and
sand-hoppers, and part of the food was small bivalves and worms.
It was also found in Loch Fyne that cod and coal-fish from 1+
to 3 inches long were feeding almost entirely on copepods.

CEeArab rine Vil

PRACTICAL METHODS OF INCREASING THE SUPPLY OF
FISH

IN recent years much attention has been devoted to measures
either proposed or actually adopted for maintaining or increasing
the supply of the most valuable kinds of fishes. These measures
consist either in the prevention of practices on the part of fisher-
men which involve the destruction of the fish while young and
undersized, or in the artificial propagation of the fish. We will
consider these two classes of measures in succession.

With regard to the protection of young fish we have to con-
sider not only whether a particular restriction or regulation will
increase the supply of adult fish, but how it will affect the
fishermen. It may be argued that any improvement in the
supply must benefit the fishermen more than any other class of
the community, but this is evidently not the case in certain
instances. For example, if shrimping is prohibited on account
of the destruction of small flat-fishes which it involves, the direct
and immediate result to the shrimpers is certainly not profit but
loss. In the application of a measure of restriction therefore,
even though it appears certain to increase the supply of the
most valuable fish, due consideration must be given to its
immediate effect on the men engaged in the fishing industries.

Theoretically the protection of young fish is extremely
simple ; it is certain that if we require the greatest number of
fish above a certain size, we should kill none below that size.
In dealing with sheep, leaving questions of pasture or ac-
cidental death out of consideration, to refrain from killing
the lambs is equally simple in practice. But it is not

136 MARKETABLE BRITISH MARINE FISHES She.

so simple in practice when we are dealing with fish in the
sea, because we cannot pick out those of the size we want
and leave the rest alive. Another principle equally simple in
theory and difficult in practice, is to regard generative maturity
rather than size, and to avoid killing any female fish until it has
spawned once, the result of which would be that there would
always be a large supply of young. In practice then we have
to consider how far we can stop the destruction of undersized or
sexually immature fish which is involved in actual fishing
operations, and here again we find two subdivisions of the
subject ; namely, first, the destruction of fish of valuable kinds
so small as to have no value in the market, and, second, the
capture of undersized fish for sale. Clearly a prohibition of sale
will only directly affect the latter kind of destruction, though it
may indirectly affect the former, in a manner which will be
considered presently.

It has been stated in Chapter V. that large numbers of very
small plaice, soles, turbot, brill, and whiting are captured in
shrimp-nets, both in those worked by hand or by a horse along
the shore, and those worked from a boat. Not all of these are
necessarily killed, and to a great extent the proportion that are
returned to the water alive depends on the carefulness of the
fisherman. But asarule the fisherman is not careful, and the
majority it may be safely said are usually killed. The only way
to prevent this destruction with certainty is to prohibit the use
of the nets in places where the young fish abound. No pro-
hibition of sale will have any effect, because the fish here
considered, fish only a few months old, have no value in the
market ; there is no demand for them as a table delicacy as in
the case of whitebait. In some cases they may be used as a
manure, but they are not usually sold for that purpose ; as a rule
they are not used at all but regarded by the shrimpers as refuse
of no importance.

As shrimping is carried on entirely or almost entirely within
the three-mile limit, its regulation is within the powers of the
District Fishery Committees, and nearly all of these have passed
bye-laws for the purpose of diminishing the destruction of small
fish involved in the capture of shrimps. These bye-laws regulate
the size of the net, the size of the mesh, the localities where
shrimping may be carried on, and the frequency with which the

VI PRACTICAL METHODS OF INCREASING THE SUPPLY 137

net must be raised and emptied. In places where shrimping is a
considerable industry, as at the mouth of the Thames or Humber,
and on the coast of Lancashire, its total prohibition is impossible,
and all that can be done is to diminish as far as possible the
destruction of small plaice, &c., which it involves. The possibility
of taking shrimps by instruments which do not capture flat-fishes
has been much considered ; one such instrument is a trap like a
lobster-trap, another a trawl with its ground-rope replaced by a
bar raised some inches above the bottom.

A certain number of saleable fish are taken in shrimp-trawls,
but we have now to consider nets used expressly for the capture
of fish. One method of protecting the smaller fish is to prohibit
trawling on the inshore grounds. Recently, in accordance with
the powers conferred upon them, many of the District Committees
have adopted this method, which must of necessity be very
effective for the purpose. The difficulty which arises from it is
the distress it causes to the fishermen. On the south coast of
Devonshire Brixham trawling vessels of small size have long been
used for trawling in the bays, and catching small plaice. A bye-
law was passed by the local committee prohibiting trawling
within certain limits, thus closing not the whole but a portion of
the territorial waters under its jurisdiction. The men engaged
in this branch of the industry have objected to the law. It may
be supposed that these men ultimately reap the benefit of
obtaining more large fish outside the prohibited limits, and
probably that is the case. But in the meantime they have to
fish in regions more exposed to the weather, and get less fish
than they did before. The diminution of their earnings and
greater labour and exposure does not however amount to distress,
and the bye-law appears to be quite justifiable.

{t is evident that the measures hitherto mentioned do not
affect the capture of small flat-fishes on the eastern grounds in
the North Sea, or on other similar grounds beyond territorial
limits. The agitation against this destruction arose among the
people engaged in the trawling industry itself, and resulted in a
demand perseveringly and earnestly put forward for the pro-
hibition of the sale of undersized fish by Act of Parliament.
It is generally admitted by those that have most experience of
the circumstances connected with the trawling for small plaice
off the continental coast, that the prohibited fish if thrown over-

138 MARKETABLE BRITISH MARINE FISHES CHAP.

board would not usually survive, but that the majority of them
would be fatally injured either by pressure in the trawl or by long
exposure and rough handling on deck. The argument is that
when the small fish were unsaleable the boats would not find it
worth while to fish on the grounds in question. If the size limit
were made high enough this result would certainly be secured.
Mr. Holt is convinced that a limit of thirteen inches for plaice
alone would make fishing on the eastern grounds quite unprofit-
able. This is probably true in the main, but it must be re-
membered that to the north of Heligoland, and probably in
other parts, a considerable number of adult soles, of turbot, and
brill of all sizes, and of plaice from 13 inches to 16 inches long
are to be found in summer, and even with a limit of 13 inches
for plaice some voyages might be made for the sake of these
other valuable fish. On the other hand I have shown that a
limit of i3 inches would cut off eighty or ninety per cent. of the
plaice taken by Lowestoft boats on the Brown Ridges, thirty to
fifty miles off the Dutch coast, that a large proportion of female
plaice on this ground under 13 inches are mature, and that the
limit of 13 inches would close such an extent of grounds to the
Lowestoft smacks, that it is doubtful whether they could be kept
at work at all. It was previously proved that in the English
Channel some females are mature when less than 13 inches long,
and that this limit could scarcely be borne by the industry there.

The limits recommended by the Sea Fisheries Protection Asso-
ciation were 12 inches for turbot and brill, 10 inches for plaice and
soles, 11 inches for lemon soles. As undersized lemon soles are
not known to abound regularly on particular grounds, and are
not found on the eastern grounds of the North Sea except in
very small numbers, there is no reason to impose a size limit
with respect to them at all. The other sizes are certainly reason-
able ; they would not unduly restrict the area over which deep
sea trawlers can work. It may be urged however that 12 inches
for turbot and brill is not high enough. These fish are not smaller
on the south coast, are so hardy that they would probably sur-
vive if care were taken to throw them overboard promptly, are
of greatly increased value when large, and lastly are confined
when small and young to shallow inshore grounds. The limit
of 10 inches for plaice and soles is certainly nearly as high as
the industry could bear; it might be raised to 11, but not

VI PRACTICAL METHODS OF INCREASING THE SUPPLY 139

higher. But, on the other hand, how much good would it
effect ?® The present writer has seen a trawler’s crew on the
eastern grounds shovel overboard all the plaice under Io inches,
simply because the price for such fish was too low to pay for
taking them to market, and at the same time this vessel made a
very good voyage out of the large soles, turbot, brill, and larger
plaice on the same ground. The limit would not entirely put a
stop to fishing on the eastern grounds, but would probably have
the effect of saving a great many plaice under the limit. Vessels
would not continue to fish in places where few other fish were to
be got. The possibility of making up a voyage by filling up the
fish hold with small plaice when the price was good would be
gone, and for this reason fewer of the small plaice would be
caught.

What then is to be said of the limits recommended by the
Parliamentary Committee of 1893, namely, 8 inches for plaice
and soles, 10 inches for turbot and brill? These limits were
embodied in a bill introduced into Parliament in 1895 but not
passed, and the National Sea Fisheries Protection Association
petitioned for its reintroduction in 1896. As far as deep sea
trawling is concerned, such limits would make no appreciable
difference at all. It is true that a few plaice under 8 inches, and
occasionally a turbot or brill under 10 inches, are taken on the
eastern grounds, but the deduction of these from the total catch
would make no change in the habits of the trawlers, and confer
no protection on the fish. These limits would, however, make
some difference to the small inshore trawlers in places where
such trawling is still allowed. A certain number of soles under
8 inches are landed by small boats at Lowestoft, and of plaice
under that size in the Humber, and the proposed limits would
protect these. The landing of turbot and brill under to inches
for sale seems to be a rare occurrence.

As the circumstances of the trawling industry and the habits
of the fish do not appear to admit of the preservation of all
plaice, soles, turbot, and brill, not to consider other species at
present, until they have spawned once, we have to face the
possibility of a continued diminution in the supply of these fish,
in spite of all protection of the young, as a consequence of the
excessive capture of the mature individuals. The trawling may
be so extended and so effective that not enough spawners are

140 MARKETABLE BRITISH MARINE FISHES CHAP.

left to produce an adequate supply of young. This point
appears to have been reached according to the experiments and
observations of the Scottish Fishery Board, for in the Firth of
Forth and St. Andrew’s Bay, notwithstanding the prohibition of
trawling in the territorial waters, and the absence of other fishing
destructive to young flat-fishes, the number of the latter has not
increased. To remedy this state of things artificial propagation
has been recommended, and in certain cases adopted. We may
here briefly discuss the question how far artificial propagation
appears capable of increasing the supply of fish, whether in
conjunction with or independently of the protection of the
young.

Firstly, it may be pointed out that up to the present time
artificial propagation of marine fishes is limited to the produc-
tion of fry at the stage when the yolk is nearly absorbed, which
are then liberated in the sea. From this stage onwards they are
no better off than fry which have been hatched under natural
conditions. At Arendal, on the south coast of Norway, and at
Dildo Island, in Newfoundland, there are two hatcheries almost
entirely devoted to the propagation of the cod. In both these
cases it is stated, and there is no reason to doubt the statement,
that a greatly increased number of fish have been seen and
captured in the neighbourhood of the hatcheries as a direct
result of the millions of fry liberated. Cod and other fish have
been hatched also in hatcheries on the coast of the United States,
but not very regularly, and in 1894 the hatchery of the Scottish
Fishery Board at Dunbar commenced operations, the latter
establishment dealing principally with the plaice. Now it may
be admitted that locally an increase in the supply of fish may
be produced by the annual liberation of some millions of fry.
But we have to consider firstly the proportion between the value
of this increased supply and the cost of the hatchery. At present
we have not the data necessary for making this comparison, but
it should be always remembered that the cost of the hatchery
has to be met, not out of the total value of the fish derived from
the hatchery, but out of the value of the fish after the cost
of catching and marketing has been deducted. The fry having
been liberated in the sea, those of them which survive to reach
marketable size have to be caught. If we suppose one firm to
have the exclusive control of a sea fishery, and to establish a

VI PRACTICAL METHODS OF INCREASING THE SUPPLY I4I

hatchery as a business enterprise, then clearly the question for
that firm is whether the resulting increase in the catch of fish is
sufficient to pay for the cost of the hatchery and leave a profit.
The nation in the actual state of matters is such a firm, and
hitherto no attempt has been made to ascertain from reliable
and complete data whether the working of a hatchery is com-
mercially profitable or not.

In the meantime we may well take some trouble to consider
how far the operations of a hatchery can be profitable, reasoning
as accurately as possible from what we know of the facts bearing
upon the question. The Scottish Fishery Board calculates that
if one in a hundred of the fry distributed from the Dunbar
Hatchery in its first two years ultimately came into the market
and realised 6d. each, the resulting value would be £18,000 ; but
the great majority of the fry were plaice, and 3d. each is a fair
average price for plaice on landing. One in a thousand sold at
1d. each would realise about £300. The number of plaice eggs
obtained at the Hatchery in 1895 were forty-four millions, and
the number of plaice fry liberated 38,615,000. Now we may
take the average number of eggs produced by a female plaice to
be 200,000, as indicated by the figures given in Chapter III.
Therefore the number of eggs above is the produce of 220
female fish. According to statistics collected by Mr. Holt, four
million mature female plaice are landed per annum at Grimsby
alone. So that for 19,090 spawners killed at Grimsby, the eggs
of one are hatched at Dunbar. It may however be supposed
that the mortality or destruction in the sea between the shedding
of the eggs and the stage of the absorption of the yolk in the
larva is greater than in the hatchery. We may suppose that the
destruction is nine times as great in the sea, which is certainly
more than the actual proportion. In that case one spawner in
the hatchery is equal to nine in the sea, or the total result of the
work of the hatchery is equivalent to leaving in the sea one
mature female out of every 2,000 killed at Grimsby, a proceeding
which would clearly not make much difference to the total supply
of plaice in the North Sea.

It may be said, however, that it does not matter how limited
the extent of the hatching operations may be, so long as the
marketable fish produced are sufficient to give a profit on the
cost of the operations, This at present we can neither prove nor

42 MARKETABLE BRITISH MARINE FISHES CHAP.

disprove. The capture at marketable size of one in a thousand
of the fry liberated, means 200 from each spawner in the hatchery
every year. It may well be doubted that so high a proportion
is possible. If there were no fishery by man the species would
soon reach its limit of increase, and then on the average each
pair of mature plaice would produce only two mature offspring
to succeed them. This would mean a survival of two out of
200,000 eggs supposing each female spawned only once. But in
the first place fish are marketable before they are mature, and
therefore more than two marketable fish would survive, and in
the second place the species being below its possible abundance
excess of food is available, so that probably a greater proportion
survive to marketable size. Then again, the eggs and fry are
protected in the hatchery. But taking all these facts into con-
sideration we may well doubt whether more than fifty out of the
fry derived from each spawner in one season reach marketable
size, and then we have to consider what proportion of these
would be caught.

At present then it must be held that artificial propagation is
in its experimental stage. There is good evidence that it pro-
duces local increase in the fish supply, the fish hatched in a
particular place being carried or migrating to other definite
areas in particular directions in consequence of currents, the
habits of the fish, &c. It is possible therefore, if proper in-
vestigation be made, to trace out the history of the fry liberated
from a hatchery, and to prove definitely what proportion of
increase in the abundance of fish is produced by its means in
particular localities. In future inquiries two points ought to
receive attention with regard to the question whether the mere
hatching of the eggs and protecting the fry for the few days
before the absorption of the yolk is of very great benefit. The
first point is the possibility of feeding and rearing the larve
until they have gone through their transformation, and even
until they are marketable. In this way a smaller percentage of
loss in the larval and young stages than occurs in the natural
conditions might be obtained, in other words longer and greater
protection afforded. The second point is whether cheaper and
larger results might not be produced by taking a very much
greater number of spawners, and merely putting the fertilised
eggs into the sea in vast quantities. Hitherto, notwithstanding

VI PRACTICAL METHODS OF INCREASING THE SUPPLY 143

great care and attention, no one has succeeded in feeding and
keeping the fry or larve alive for more than a few weeks, but it
seems possible that the difficulties will be overcome in the future
by keeping the fry in large enclosures supplied with suitable
food and pure water. At Plymouth plaice fry were found to
take both minute organisms obtained from the sea, and artificial
food in the form of minute particles of minced sea-worms. The
exact cause of their ultimate death was not evident. As to the
second point, the decrease in the supply appears to be largely
due to the diminution in the number of mature fish in the sea.
The hatchery may be regarded as a reserve of spawners, and
there is no reason except that of cost why thousands or even
millions of spawning fish should not be kept at suitable places
on the coast. The mere collection of fertilised spawn would
certainly be cheaper and less laborious than the hatching of the
eggs in ingenious and complicated apparatus.

In connection with all measures for increasing the fish
supply the importance of reliable statistics becomes evident.
All who have had occasion to occupy themselves with these
questions have felt the inadequacy of the statistics hitherto
available. The Board of Trade furnishes tables which profess
to give the quantities of particular kinds of fish landed at
particular ports, and the total quantities landed on our coast.
But the difficulty is that we are not enabled by these tables to
compare the yield of given areas in different years, or the rela-
tion of the fish caught to the number, size, and character of
the fishing boats. A larger total yield generally means an
increased number of boats and a larger area exploited, and is
accompanied by a diminished supply from grounds which have
been long worked. It is obviously unsatisfactory to endeavour
by complicated administrative machinery to increase the fish
supply, without the power of ascertaining whether any result
has been produced, or how much result. It appears that the
only satisfactory method of investigating the fish supply is to
record the catch landed from every boat, and the region where
the catch was taken. It may be thought that this is impractic-
able, but a little consideration will show that it could be carried
out without much difficulty. There is a collector of statistics
at every fishing port at present, but he has no means of obtain-
ing accurate and complete results. If every master of a boat

144 MARKETABLE BRITISH MARINE FISHES CHAP. VI

or net were compelled by law to declare the quantity of fish he
landed in the ordinary local measures, and his place of fishing,
the local officer could easily keep a record of all the fish landed,
and the number and character of the boats which landed it.
To take an example: we could ascertain from such a record
how many trawlers, steam and sail, fished on or near the Dogger
Bank in a given year, and so ascertain the whole quantity of
fish taken there, and the quantity per boat. In this way we
should have a real and certain knowledge of the condition of all
our principal fishing grounds. Hitherto Royal Commissions
and Parliamentary Committees have been appointed from time
to time to find such things out, and have necessarily failed to
do so. Statistics of the kind here recommended have already
been extensively collected by the Scottish Fishery Board, but
what is required is that the system should be made complete so
as to cover all boats and all fishing grounds. It may be
supposed that fishermen would not give true information about
the ground where they had been fishing, but every one who has
experience of fishery affairs knows that a competent man can
tell from the nature of the catch whether a statement made
as to its place of capture is approximately correct or not. Any
man, for instance, would be capable of distinguishing in his
returns between fish from the coast of Iceland and fish from
the neighbourhood of Heligoland, and this is the kind of
distinction which is required.

Pek Did

Pooky Or (PARTICULAR FISHES

Ee RING JP Avni.

THE fishes of this family have no spines in any of their
fins. They have a single short dorsal fin placed near the
centre of the back, and usually a short ventral fin placed
in the hinder part of the body near the tail. The pelvic
or abdominal fins are below the dorsal or a little in front
of it. There are never any barbels, the body is covered with
scales, which are thin and spineless, and the head is without
them ; the edge of the belly is usually more or less sharp, and
covered with a row of scales which have keels ending in sharp
points. The teeth are small and weak, the mouth large. The
gill-openings are large. The lateral line is in nearly all cases
absent. There is a well-developed air-bladder communicating
with the hinder end of the stomach. The body is bluish or
greenish on the back, very silvery and with iridescent colouring
on the sides.

These fishes are never of very large size. They live in shoals,
and swim always in mid-water or near the surface, feeding
entirely on small free-swimming creatures, chiefly Crustacea.
They do not usually seize single creatures with their jaws, but
strain them from the water by means of the sieve-like apparatus
formed by long projections on the gill-bars, known as gill-
rakers.

The gill-rakers can be easily seen by raising or removing the
gill-cover of either side in a herring or sprat. On the first or
uppermost of the bars to which the gill-fringes are attached will
be seen a row of stiff, pointed projections like the teeth of
a comb or a rake. These are directed forwards towards the gill-
cover and the throat, and the water that passes over the gills
has to pass between them. Fishes of this family occur through-
out the temperate and tropical regions. They belong to the

LE, 2

148 MARKETABLE BRITISH MARINE FISHES

neighbourhood of the coasts ; none are found in mid-ocean, and
none in the ocean abysses. Many species on the other hand
approach towards fresh water at certain seasons, ascending
estuaries and never going far from them; but no species is found
only in fresh water, although there are colonies of certain species,
such as shads, which have established themselves in lakes and re-
main there permanently and breed there. All these fishes occur
in very large numbers, and partly from their method of feeding,
partly from the persecution of numerous enemies to which they
are exposed, they are very timid and restless and swim with very
creat rapidity. In consequence of these habits they are only
caught with the drift net or the seine, or in bag nets and traps
in narrow waters ; the use of hooks for their capture is exceptional
and unimportant.

There are six kinds in British water, all valuable as food, and
several of them of great importance commercially. The following
is a list of them with their chief distinctions :—

I. Species in which the mouth is at the end of the snout and
the lower jaw somewhat longer than the upper. The sides of
the upper jaw come forward when the mouth is open, and close
the sides of the gape.

1. The Herring.—Dorsal fin commences midway between
the end of the snout and the base of the tail; the pelvic
fins a little behind the commencement of the dorsal.
Scales of moderate size ; edge of the belly not very sharp
and the spines on it short and weak. No radiating lines
on the gill-covers.

. The Sprat.—Dorsal fin a little farther back than in the
Herring; the pelvic fins very slightly in front of the
commencement of the dorsal. Scales of moderate size ;
edge of the belly very sharp, and the spines on it strong.
The body is rather deep and flattened from side to side.
No radiating lines on the gill-cover.

The Pilchard.— Dorsal fin commencing nearer the snout
than the base of the tail; pelvic fins under the middle
of the dorsal. Scales large; the edge of the belly rounded,
and the spines on it weak, not sharp. Radiating lines
on the gill-cover spreading from above downwards.

4. The Allis Shad.—Like the Pilchard in other respects,

i)

Oo

THE HERRING FAMILY 149

but the scales are smaller, the belly spines much stronger,
the body deeper behind the head. The gill-rakers long,
thin, and numerous.

5. The Twait Shad.—Distinguished from the Allis Shad
best by the gill-rakers, which are sharper, thicker, and
fewer ; a row of dark spots along the side from the head
to a point behind the dorsal fin.

II. Species in which the snout projects beyond the mouth, so
that the latter is beneath the head ; the sides of the gape un-
protected when the mouth is open, and the gape itself reaching
back far behind the eyes.

6. The Anchovy.

Of these six species the pilchard is the most truly marine
in its habits, but is nevertheless, at some places, as at St. Ives,
taken in very great numbers by the seine; it seldom enters
estuaries. The anchovy also is not found in estuaries. Sprat
and herring are found in brackish water, especially in the
young state, while the shads regularly ascend rivers in order
to spawn.

The eggs of these fishes have certain common peculiarities of
structure, but the conditions in which they are placed to undergo
their development are extraordinarily various. The spawn of the
herring is deposited in the sea or near the mouths of rivers, and
is heavy and adhesive, so that it sticks firmly to stones or fixed
objects on the sea-bottom. The eggs of the sprat and pilchard
on the contrary are of the buoyant kind, and float about
separately in the sea like those of cod or flat-fish ; the eggs of
the anchovy are also buoyant and marine. The eggs of the
shads are shed in fresh or nearly fresh water, and develop at the
bottom of rivers, but they are not adhesive, remaining free and
separate during development. The peculiarity of structure in
which all the eggs resemble one another is that the yolk is com-
pound, made up of a number of separate portions. In the
herring these yolk masses are globules of various sizes and the
eggs are not very transparent. In the other kinds the yolk
masses are not globular, but angular from mutual pressure, and
the eggs are quite transparent. —

The hatched larva is very long and slender, and in all cases

150 MARKETABLE BRITISH MARINE FISHES

transparent, the vent is nearer to the tail than to the yolk-sac.
The larva grows greatly in length, and remains very slender
until its transformation takes place.

The Herring (Clupea harengus).

Principal Characters —The pelvic fins behind the commence-
ment of the dorsal, which commences midway between the tip
of the snout and the base of the tail; nine rays in the pelvic
fin. Scales of moderate size, thin, and deciduous ; spines on
the belly weak, and the edge of the belly rather blunt. No
radiating lines on the gill-cover. Small easily detached teeth
on the jaws, on the roof of the mouth, and the tongue. The
hinder end of the upper jaw is beneath the middle of the eye.
The colour a more distinct greenish-blue on the back than in
the sprat. Seventeen inches is the greatest length recorded ;
the largest occur in the north—lIceland and Shetland ; in Britain
they seldom exceed 12} inches.

The points of difference between the herring and sprat in
specimens of 2 inches long or less require some attention and
care to distinguish, although they are perfectly certain and con-
stant; in whitebait the young of the two kinds are usually
mixed together. Besides the above points, the number of
vertebre in the sprat is never more than forty-eight, in the
herring never less than fifty-four.

FHlabitat—F rom the White Sea to the Bay of Biscay, absent
from the Mediterranean. It occurs alsoon the American side of
the North Atlantic, but not in the Pacific. It isabundant all round
the British and Irish coasts, but chiefly in the North Sea and
along the east coast of Scotland. In the English Channel the
fishery is of less magnitude, and the quality of the fish inferior.

Breeding.—The proportional numbers of the sexes have been
found in herrings to be very nearly equal, but there is a slight
excess on the side of the males—namely, ninety-nine females to
one hundred males. The sizes have not been compared with
sufficient accuracy, but the testes were found to be on the
average heavier than the ovaries, so that it is probable that there
is a slight excess in size on the side of the males.

According to the careful calculations of Dr. Fulton, the herring

Se

THE HERRING FAMILY I51

is not individually a fish of very great fecundity. In sixteen
specimens, 93 to 12} inches long, the total number of eggs
varied from 21,000 to 47,000, the average being 31,000. All
these specimens however were winter herring—herring that were
ripe between January and March on the east of Scotland ; most
of them from the entrance of the Firth of Forth, a few from
Wick.

The questions connected with the spawning periods and
spawning places of herrings form a subject of which the investi-
gation in this country is by no means exhausted. It is certain
that herrings are found spawning in winter, and also in summer
or autumn, and that the spawning periods differ considerably in
different localities. It is not merely that in one neighbourhood
the fish spawn in the beginning of the year, and in another at
the end of summer, but that two spawnings have been definitely
observed in the same neighbourhood. Considerable evidence
has been obtained upon this complicated subject, and the
conclusion to be drawn from this evidence is that the same
herrings do not spawn twice a year, but that, on the contrary,
the fish which spawn in winter are a different race from those
which spawn in summer. These races differ in their habits and
spawn in localities of different character. Winter-spawning
herrings frequent brackish waters, and do not spawn far from
the coast or the openings of rivers, while the summer spawners
are herrings of the more open sea which, although they approach
the coast in the spawning season, do not seem to enter estuaries,
and whose spawning grounds extend to a considerable distance
from the coast.

The herrings of the Firth of Forth are winter herrings.
Their movements and spawning are regularly repeated every
year both as to time and place. The spawn of herrings was
first obtained from the natural beds and examined in the case
of these herrings, in Professor Allman’s investigation already
mentioned in a previous part of this book. The fish first
appeared, and the fishing in the upper parts of the Firth, below
Queensferry, commenced about the last week of October, 1861.
The herring were fished in the lower parts in January, 1862,
and up to the end of January the fish taken were full. Spent
herrings were taken on February Ist. After fruitlesss search in
other parts of the Firth spawn was first obtained on March Ist

152 MARKETABLE BRITISH MARINE FISHES

near the Isle of May, and continued to be dredged there in
abundance till March 13th. The spawn was sticking to stones,
gravel, and shells in great abundance. The ground where the
spawn was deposited was stated to be too rough and rocky for
trawlers to work over.

When the present author was stationed at Granton in the
years 1884-87 he had frequent opportunities of repeating Pro-
fessor Allman’s observations. He found evidence that the
spawning commenced as early as January 18th. The ground,
however, was not altogether unvisited by trawlers. At that
time a number of steam trawlers worked from Granton, and
in January, February, and March these used regularly to
trawl over the herring-spawning ground for the purpose of
netting the immense number of haddocks which congregated
there to feed on the herring spawn. On one occasion a trawler
got his trawl so full of haddocks that he could not hoist it on
board, but towed it to Granton harbour with the fish in it.
These haddocks were found to have their stomachs gorged with
herring spawn.

Another regular winter-herring fishery which has _ been
studied by naturalists is that of the Ballantrae Banks on the
west coast of Scotland, off the village of that name in Ayrshire.
Here the spawning takes place in February and March, and an
examination of the beds and of the spawn, which was dredged
up from the gravelly bottom in large quantities, was made in
1884 by Professor Ewart on behalf of the Scottish Fishery
Board. Another naturalist, Mr. George Brook, studied the
movements of the herring in the Firth of Clyde for several
months, and considered that the famous Loch Fyne herring were
fish which entered that loch after shedding their spawn on the
Ballantrae Banks. It would seem extremely probable in this
case that the Loch Fyne herring are hatched and reared within
the limits of the Firth of Clyde, and belong to that region as
permanently as perch or pike belong to their own river. At the
same time it must be mentioned that spawning herring were
found in Kilbrennan Sound and near Campbelltown in August
and September, and whether these are also local fish, or a race
belonging more to the open sea, there is not sufficient evidence
to show. We have at present no reason to suppose that the
same herring spawn twice a year.

THE HERRING FAMILY 153

The herring of Plymouth are another race of winter herring.
The full-grown fish are captured from October or November
onwards in Plymouth Sound, and their roes are in the full
condition, gradually approaching ripeness. Spawning takes
place only in Bigbury Bay, which is just outside Plymouth
Sound to the eastward. But although it has been regularly
observed that the ripe fish pass out to that locality in January,
followed by the fishing boats, and that the spent fish and the
newly hatched larve are taken there in numbers, yet in spite of
continued and careful searching with the dredge we have never
succeeded in obtaining the spawn from the bottom. Spawning
continues until the beginning of March. Winter herring are
known, and give occasion to fisheries of greater or less import-
ance at various other places round our coast, but up to the pre-
sent time no other spawning places than those above mentioned
are accurately known.

The summer herring are more abundant and give rise to
more important fisheries. As in the case of the winter
herring, although large numbers are caught when they are
not spawning, or about to spawn, the largest fisheries depend
on full or ripe fish, and when the spent fish begin to form a
large proportion of the catch the fishery is nearly over. The
greatest of such herring fisheries are those of the North Sea,
along the east coasts of Scotland and England, and the fish are
taken at distances varying from two or three to fifty or sixty
miles from the coast. Along the north-east coast of Scotland
from Wick to Aberdeen the great herring fishery lasts from the
middle of July to the end of August, and spawning takes place
principally in the latter month. At Wick there is also a
winter spawning in January. The spawning grounds in this
district are not properly known; fishermen point out certain
grounds as those where herring spawn is deposited, but the
localities have not been determined from actual examination by
experts. In all probability the trawlers do sometimes bring up
herring spawn, and know particular grounds where they catch
haddock in unusually large numbers, because those fish are
attracted thither by herring spawn, but this kind of evidence
has not been criticised with scientific accuracy. Dr. Fulton, in
the Ninth Report of the Scottish Board, published charts
showing the position of such alleged herring-spawning grounds

154 MARKETABLE BRITISH MARINE FISHES

on the evidence of Fishery Officers. But, on the other hand,
these Officers have forwarded to headquarters pieces of hydroids
from the sea bottom bearing small clumps of adhesive eggs,
which they supposed to be herring spawn, and which are now
known to be the spawn of the little sucker-fish called Liparis.
Herring spawn when found is always in irregular masses or
layers without any particular size and arrangement, while these
clumps are rounded, and all of about the same size. The
search for the actual deposits of herring spawn is by no means
easy. In an expedition for the special purpose of this search
in August, 1883, in which the author took part, and which was
made in the Moray Firth on board the Jackal in the service of
the Scottish Board, in spite of numerous dredgings no herring
spawn was obtained.

I have been informed however by Mr. James Alward, of
Grimsby, that it is well known to himself and to the line fisher-
men of that port that herrings spawn regularly every year in
August and September on the rough ground of the west shoal
of the Dogger Bank, and that it used to be the practice to look
for herring spawn adhering to the grease placed at the end of
the sounding lead, and to shoot the lines where the spawn was
found, the fishermen knowing by experience that an abundant
catch of haddock could be confidently expected on ground
where herring spawn was lying.

From Aberdeen southward to Northumberland the principal
spawning time is August and the early part of September, and
further south it becomes later, off Yorkshire taking place chiefly
in October, while at Lowestoft and Ramsgate it occurs in
November. Although the actual spawning grounds are un-
certain, nothing is easier than to obtain the spawn from the ripe
fish on board a fishing boat at any of these places. It can be
received on glass plates, and if placed in water with a little milt
becomes fertilised, and can be hatched on shore provided a
constant supply of clean sea-water is maintained.

The most complete investigations of the spawning of herrings
in their natural condition, and of the natural history of the fish
generally, are those made and published by a Commission of
German naturalists at Kiel, in the Baltic. This was a Com-
mission for the Scientific Investigation of the German Seas,
instituted in 1870 by the Prussian Minister of Agriculture and

THE HERRING FAMILY 155

Industries, and its researches upon the herring were continued
from 1874 to 1882. With regard to the spawning times and
places, the investigations proved that the spring herring
spawned in waters of little saltness and in shallow places in
the Western Baltic from the beginning of April to the middle of
June. In the river Schlei herring of this race actually spawn
in water which is all but fresh, and the spawn is found attached
to fresh-water plants. The autumn or sea-herring, on the other
hand, were found to spawn in the salter, deeper water of the
Great Belt and on the Mecklenburg coast from September to
the middle of October. One spawning ground off the island of
Langeland was at a depth of one to four fathoms, while the
depth of the spawning ground of the spring herring in the
Schlei was only 23 to 3 feet.

One of the members of this Commission carried out a most
laborious and profound examination of the minute peculiarities
of herring from different localities, and satisfied himself that
the different races could be distinguished by certain com-
binations of characters when a sufficient number were examined,
although the differences were not sufficiently great to enable
one to distinguish with certainty a single specimen by itself.
He examined sixteen different local forms, and found that they
were all distinguished by particular combinations of minute
characters. Among these sixteen were the autumn herring of
Peterhead, autumn herrings from the coast of Sweden, spring
herrings from Bergen, the above-mentioned forms of the Baltic
and others. But the sixteen different races formed three groups,
whose differences were more pronounced—namely, a number of
local races spawning in salt water, two races spawning in
brackish water, and a third group, consisting principally of a
Norwegian and an Iceland race. The view to which these
results tend, whether they can be considered conclusive or not,
is that a particular breed or race of herrings belongs to every
particular spawning ground, and returns to it regularly every
year in order to spawn there, and that on the British coasts
these local breeds form two groups between which the differ-
ences are greater than those which separate the several breeds
themselves. These two groups are the autumn herring and the
spring herring.

These results have not yet been confirmed by British

156 MARKETABLE BRITISH MARINE FISHES

naturalists, nor has the method been applied to many of the
British races. Mr. Duncan Matthews made an extensive ex-
amination of Scottish herrings, and detailed the results in the
Fourth and Fifth Reports of the Scottish Board, and his conclusion
was that the German naturalists’ results could not be considered
as applying to the forms examined in Scotland. But Mr.
Matthews does not seem to have applied the German method
in such a way as to make a thoroughly sufficient trial of it, and
his opinion cannot be regarded as conclusive.

Putting aside this extremely technical method of examination,
we have the certain fact that particular spawning grounds are
visited once a year regularly at the same season, while other
grounds are used at another time of the year. It seems only
possible to conclude from this that a particular ground belongs
to a particular breed of herrings which uses it from generation
to generation, although it happens at times that particular
grounds are deserted for a succession of years. Many cases are
known where such grounds have been regularly used for a very
great number of years. How then can we account for the fish
always coming back to their own ground? This need not be so
mysterious as it appears at first sight. Conditions of tempera-
ture and food very probably always drive the young fry from a
certain ground in one direction, for instance up an estuary,
There they remain together and meet with others a year older.
The year-old forms when ready to spawn for the first time very
probably join the shoals of mature fish when they revisit the
same neighbourhood, and so without any marvellous instinct
accompany them to the spawning ground which they already
know from habit and memory. The case is similar to that of
migratory birds ; it is not entirely an incomprehensible intuitive
instinct, but a more comprehensible instinct of joining the older
flocks ; the simple habit of herding in flocks or shoals is probably
the explanation of the whole matter. In order to obtain more
certain knowledge about the migration of herrings a great deal
of systematic and organised investigation will be necessary. We
may safely consider that the old theory which taught that the
home of the fish was in the northern seas, and that they annually
migrated southwards in one great body at the same time, and
that this was the reason why the fishing season was later at
southern parts of the east coast than at the northern, is exploded.

THE HERRING FAMILY 5 y/,

For if this theory were true, it is clear that the herrings could
not be in the ripe and spawning condition at every stage of their
journey, and they actually are full and ripe at each place where
the summer fishing is carried on—at Wick in July, at Lowestoft
in November. The fish that spawn at Lowestoft in November
cannot be the same fish which spawned off Dunbar in September.
We must conclude that the fish which escape the nets of the
fishermen after spawning in any district depart and go back by
the way they came. But still they must even on this more
correct view come and go, and we have to consider whence
they come and whither they go. We have good reason to
believe that adult herrings do not remain in the North Sea in
very large numbers except in the spawning season, at least not in
the narrower southern parts of the North Sea. We are com-
pelled therefore to conclude that they retire to the deeper, more
northern waters of the Norwegian Sea. The migration in fact
appears to be towards the coasts and away from the coasts.
Different shoals seek different spawning beds at different times
of the year. But to what distance their migrations extend, and
whether they remain in shoals after they leave the spawning
grounds, or disperse, are questions which we cannot answer.

The appearance of the egg of the herring under the micro-
scope is shown in Fig. 84. The yolk is composed of a large
number of small spherules, as in the case of other adhesive eggs,
but there are no separate oil-globules. The space between the
egg-membrane and its contents is greater than it usually is in
buoyant eggs. The egg when shed is globular, but its surface
becomes flattened where it is attached to other eggs or to solid
objects. The size of the egg varies somewhat in different
localities ; at Ballantrae it was found to be 1°5 mm. (;8>5 inch)
across after fertilisation. In the developing egg the embryo is
long compared to the size of the yolk, so that before the tail has
grown out into a free projection the head and tail almost meet
round the yolk.

The time occupied in development before hatching varies
with the warmth or coldness of the water. Eggs obtained in
August off the Farn Islands and kept at 52° to 58° hatched out on
the eighth and ninth days. Eggs obtained at Plymouth on
January 26th hatched in from twelve to fourteen days at the
temperature of about 48°. In experiments made at Kiel it was

158 MARKETABLE BRITISH MARINE FISHES

found that eggs kept in water at 32° took forty-seven days to
hatch, and many of the larve were deformed ; at 33° and 34°
however they took only a little less time, and were uninjured.
The newly hatched larva (Fig. 85) is 5°3 mm. (over + inch) in
length, and is more developed than the young of fishes which are
hatched from buoyant eggs. The eyes are black, and the mouth
is open, but the latter is on the lower surface of the head and

Fic. 84.—Egg of the Herring, the embryo about half developed, alive,
and magnified,

the jaws are not developed. The gill-slits are also open, but
there is no gill-cover. The intestine extends back a long way
behind the yolk-sac, the vent being near the end of the tail. The
fin-membrane extends along the back and round the end
of the tail, and also between the vent and the yolk-sac. There
is very little pigment on the body, only a few black specks, none
on the fin-membrane. After the yolk-sac is absorbed the little
fish continues for some time to grow in length without becoming
much thicker. The jaws develop, and by the time the larva is

THE HERRING FAMILY 159

,', inch long fine fin-rays appear in the tail and in the middle of
the back, indicating the dorsal fin. The ventral and pelvic fins
appear later. After the larval fin-membrane has disappeared,
when the little fish is rf to 1 inches long, although the bones
of the head are well developed the body is still slender and very
delicate and transparent, having neither scales nor silvery layer
in the skin.

The transformation of the larval herring, or the most import-
ant changes, take place in the case of the spring herring of the
Baltic, and probably in other spring races, between the ages of
two months and three and a half months, and between the lengths
of 1 inch and 14 inches. The change consists in the develop-
ment of the scales and silvery layer in the skin, and the growth
of the body in depth and thickness. During this change the
dorsal fin passes forwards nearer to the head. When the fins

‘igh ALP,
f Pp EEN Ts

oe
70 Yaa as in an ew ws oo
a) 1030)"
Sopa prey

Fic. 85.—Larva of the Herring newly hatched, alive and magnified.

first appear the dorsal is considerably behind the pelvic, and
nearer to the ventral than in the adult fish, but after the change
the commencement of the dorsal is in front of the pelvic or
hinder pair of side fins.

The most accurate and complete observations on the history
and growth of young herring are those made by the German
naturalist Meyer in the Baltic in the neighbourhood of Kiel.
An account of these will first be given here, and then some
observations on young herring in our own country will be de-
scribed and compared with them.

The spawning of the spring herring at the mouth of the river
Schlei begins at the end of March, and takes place principally
in April and May. At the end of May, 1874, numerous young
(larve) derived from this spawning were netted in the Schlei, and
were found to be 1 inch to 1} inches long, on June roth others

160 MARKETABLE BRITISH MARINE FISHES

were captured which were 1,3, inches long, and on June 23rd
others 1,5; inches. The specimens taken at the end of May and
June roth must have been hatched about the middle of April,
and so would be about six weeks old.

It was found that the transformation from the scaleless, trans-
parent, larval condition, to the condition of perfectly formed
small herring took place in the Schlei in July, and by the end
of that month the majority had got beyond the intermediate or
transition period and were fully developed. They were then 14
to 2! inches long. The process of change, and the time required
for it, were observed not only by the capture of specimens from
time to time, but also in specimens confined in a floating box.
These specimens were I inch or a little more on June 11th when
the experiment commenced, and on August Ist, or after about
six weeks, were 14 inches long, and were silvery and covered with
scales.

At the end of August and beginning of September the little
herrings left the mouth of the river and were found in the
neighbouring bays, but mixed with other larger herrings evi-
dently derived from a different and earlier spawning. Meyer
therefore measured the growth by taking the lengths of the
smallest fish in each catch ; the results were these :—

Inches.
1576:—-UAthy November as eueseeeneeceer nae Bi
Endsote Novemberernsesst ae meters 3°5
IByoVel. Oni, IDYeyeresnallotie Sa nasacer nonnoasanens 3°9
Ie g=—VONGL CO} \EVOWENGY soe gconasnoodouconadeane 4°3
IBjavl Oe IPE AWEN Asoc con decbodessyadeonac 4°5
IDiveh@! WIEHAN pss Asouconee Pooonosccnseos 4°9
EmduoteApriliie ass ccsecoceerae rate sane 574

As the smallest fish only were measured, we may conclude
from this that these herrings were 5 to 6 inches long when one
year old.

In 1878 the same naturalist took a great deal of trouble in
order to try to rear in confinement herring larve hatched from
artificially fertilised eggs. The larve were placed in a large tub
about three feet wide and two feet deep, with a wooden cover. A
hole was made in the side about midway between top and
bottom and plugged with a sponge. Through this the water
gradually drained away until it was level with the hole. Clean
water from the Bay of Kiel was poured in once a day. After

eS a . e e

THE HERRING FAMILY 161

the eleventh day of age the larval herring began to die off, and
those which lived did not grow very fast. Food was found in
the intestines of some specimens, and consisted of the minute
larvee of common bivalve and univalve molluscs. On the forty-
seventh day after the fertilisation of the eggs the survivors
measured only 32 inch, while the free larve in the Schlei
measured 47 inch. The water up to this time had been poured
in through a cloth, to keep out animals which might feed on the
little herrings, but after this it was poured in directly and then
the young herring obtained more food, eating the small crustacea
in the water, and at the end of five months were as large as the
young fish of the same age in the Schlei. The lengths observed
were as follows :-—

Age from fertilisation Length of captive Length of young herring
of the eggs. specimen. in the R. Schlei.

Inches. Inches.

TPRULOM theme pee ae ss eeinoele Sti PA arse cen tenons 4i— 38

DA") iether center. Oe at a amt oat as Aeon Ix’, — 134
MRO BORN [Ee Ae iach iat aint. lip rea IF ee Ga Gtk GRaEOeY aaon oar ae I+ --2

1 1 2

Zhe doce GIN Ree GPE AAT Dll snodbo oosonwesbosat2e =e

5 23__94 a3 __54

ai APO One Amc eE GEG ee Ba Deh apatite cia tinel Sees eh ISS E 23

With regard to the growth in the second year, Meyer first of
all considers the size or length at which herrings spawn for the
first time. According to his own experience the smallest ripe
herrings were 7°9 inches long, and since at a year old they were
not so large as this, but only 54 to 6§ inches long, he considers
that they begin to spawn at two years of age. This, although
a probable conclusion, can only be regarded as a_ preliminary
conjecture, and a thorough investigation of the question, based
on a large number of observations extended over a consider-
able time at one place, has yet to be made.

A few observations on young stages of herring in our own
country are worth mention, as giving some, although not very
complete evidence on the history and growth of the fish. It is
well known that the whitebait caught for the London market in
the lower reaches of the Thames has been fully proved to be a
mixture of young herrings and young sprats in varying propor-
tions. In the Fourth Report of the Scottish Board is contained
a paper giving the results of an examination of samples of
these whitebait. These results are shown in the following
synopsis :—

M

162 MARKETABLE BRITISH MARINE FISHES

Month. | pene ee Sere | Condition of the Herrings.
February. 1,400 | 7 Some under 2 inches.
March....| 1,200 | 5 Some nearly 4 inches.
Noy alll cone | 800 14 | 12 per cent. of the herrings under 14 inches |
| | | without scales.
WeLetiyataeere= 600 30 40 per cent. of the herrings 2 inches long and
| | completely scaled; 60 per cent. 13 to 1}
| | inches and only partly scaled.
mle seems | 800 | 87 | 60 per cent. of the herrings fully scaled 2 to 24
| | | inches long; 40 per cent. I to 14 inches}
scaleless or nearly so.
| Frulay.’..2.-. 660) 75 14 to 24 inches. |
August ... 500 | 52 | 2 to 3 inches. |

It is evident from this that larval herring not yet transformed
to the fully developed condition began to appear in April, were
most numerous in May, and were still a large proportion of
the whole in June, while the older scaled forms became
more numerous in June and July, and in August no larval
forms remained, all the young herrings being over 2 inches in
length. All this points strongly to the occurrence of a spring
spawning at the mouth of the Thames in March and April, but
unfortunately such spawning has not been sufficiently investi-
gated. But in Yarrell’s Brztzsh Fishes, first edition, vol. ii., p. 117,
there is an account of certain herring which that author found in
the Thames. They were captured by the sprat fishermen, and
were heavy with roe at the end of January, spawning in February.
They were small, only 74 inches long, and Yarrell considered
them to be a distinct species. The fishermen of Leigh, on the
north shore of the Thames estuary, maintain that the herrings
they catch in winter, which they call “yorlings,” a corruption
apparently of yearlings, are not the same as sea herrings, but a
different variety. These are apparently the same which Yarrell
described, and probably are a race of spring, brackish-water
herrings belonging to the mouth of the Thames. It is probably
from these herrings, whose spawning may continue in March and
April, that the young which form so large a proportion of Thames
whitebait are derived. The actual place, however, where the
spawn is deposited has not been ascertained.

The history of the larve hatched on the spawning beds of
the Isle of May in the Firth of Forth, has not been completely

THE HERRING FAMILY 163

traced out. The newly hatched larve were obtained at St.
Andrews in March, and specimens a little older were obtained
in abundance in April. It is probable that the majority of these
young herring pass the first year of life in the upper reaches of
the Forth, but they have not been examined. In December,
however, it was found! that considerable numbers of herring
34 to 54 inches long were taken in the sprat fishing of the Firth
of Forth. These must be considered to be derived from the Isle
of May spawning in the previous spring.

At Plymouth, again, the history of the herring hatched in
January, February, and March has not been completely traced.
In 1895 the larve occurred in the tow-nets in January. In May,
1889, a large number of small herring were taken in a ground
seine in the Cattewater, the estuary of the Plym ; these measured
4°3 to 5°5 inches in length, and were judged to be year-old fish,
hatched the previous spring in February and March. In October
herrings of 5 to 8% inches are abundant in the Hamoaze, and
these are probably the mixed broods of two years.

The history of the summer or sea herring is still less satis-
factorily known than that of the winter or spring herring. Ac-
cording to the observations of the naturalists at Kiel, the young
of the autumn herring are taken mixed with those of the spring
herring in July and August, in the bays of the Western Baltic.
These fish are 2°5 to 3°7 inches long at that time when they are
8 to 10 months old. The German naturalist Heincke found
that the larva of the autumn herring was different in shape from
that of the spring herring, and that its transformation took place '
later, when it was of a larger size, so that it was never less than
2 inches long when the perfect form was reached. No observa-
tions of any importance have been made on the young of the
summer and autumn herring in this country. It may be men-
tioned, however, that among these herring in the fishing season
a considerable proportion of mature ripe fish are only 8 to 83
inches long. These in Scotland are usually called matties, a
term which is sometimes supposed to be applied to herrings that
are not full of roe, but immature. These are really the smallest
mature, and may be taken to show the size at which maturity
is reached in the autumn herring, the age being as before
mentioned two years.

1 Sprat Fishing on the East Coast of Scotland in the Winter of 1883-84.
Second Report of the Fishery Board for Scotland.

Ml

164 MARKETABLE BRITISH MARINE FISHES

The Sprat (Clupea sprattus).

Distinguishing Characters——The dorsal fin commences a little
behind the middle point between the snout and the base of the
tail fin, and the pelvic fins are very slightly in front of the com-
mencement of the dorsal. There are seven rays only in the
pelvic fin. The scales are a little larger than in herring of the
same size. No teeth on jaws, tongue, or roof of mouth. The
spines on the belly strong and sharp, and the edge of the belly
narrow, so that it is like a saw. The body deeper than in the
herring. The hinder end of the upper jaw not reaching back so
far as the middle of the eye. No radiating lines on the gill-
cover, the lower edge of the opercular bone not slanting
upwards and backwards so much as in the herring, and straight.
The colour of the back rather dull and slaty. Does not exceed
63 inches in length, usual size 4 to 5 inches.

Flabitat.—From the north coast of Europe to the Mediter-
ranean. Found all round the British and Irish coasts. There
are large fisheries of sprats in the neighbourhood of the Thames,
on the Kent and Essex coasts, and along the south coast of
England, as in the Solent and at Torquay. They are also taken
in the Forth and Tay, and in the Moray Firth. In narrow waters
they are caught in stow-nets, as in the Thames, the Wash, and
the Forth. At Dover they are caught with small-meshed drift-
nets, and at Torquay in seines.

Lreeding.—The proportions between the sexes have not been
carefully studied, and the investigation of the number of ova by
Dr. Fulton was imperfect, as the roes were not very ripe or very
fresh. He calculated in one specimen the total number of eggs
at 5,400.

Ripe sprats are not often seen in large numbers, not usually
being taken in this condition in the regular fisheries. The reason
of this appears to be that the fish go some distance from shore
in order to spawn, and there is no regular pursuit of them in the
ripe condition. The case resembles that of the pilchard. The
spawning season must therefore be determined rather from
observation of the presence of the buoyant eggs in the sea than
of the proportion of ripe fish taken. It is probable that if small-
meshed nets were used, and a careful trial made, numbers of

THE HERRING FAMILY 165

spawning or ripe sprats could be captured. But it happens that
the longshore fishermen who capture sprats do not fish in the
open sea, and the deep-sea fishermen do not use nets which are
capable of catching sprats.

When the reproduction of the sprat was first considered, it
was naturally supposed that its mode of spawning would probably
prove to be closely similar to that of the herring. In 1884 Mr.
Duncan Matthews wrote that he obtained sprats with full roes
and milt from the coast of Scotland only in May and June, and
that many were so ripe that the roe could be readily expressed
by the hand, when it presented much the same appearance as
the spawn of the herring under similar circumstances. He gave
a figure of the spawn pressed out in the form of a string of eggs
lying on a glass plate. In the same year I published a descrip-
tion of a pelagic or buoyant fish-egg, the parent of which was
unknown. This egg was obtained by me in the Firth of Forth
in May and June, and it has since been proved that it is
the egg of the sprat. The same egg was described about the
same time by Victor Hensen from the Baltic, and that observer
first suggested that it belonged to the sprat, an identification which
he afterwards proved to be correct by pressing the eggs from a
perfectly ripe sprat. I have myself been able to confirm the
identification by examining eggs pressed from ripe sprats at
Plymouth. On board a trawler on February 12th, when the net
was hauled after being towed from Looe in Cornwall to a point
about five miles from Plymouth Breakwater, I found two sprats
amongst the fish caught. One of these was a perfectly ripe
female, and I pressed out a number of eggs, which floated in the
sea-water, and which were taken ashore and carefully examined
with the microscope. ‘They were not fertilised, but they showed
the peculiarities so well known in the egg taken by the tow-net
from the sea.

The spawning period of the sprat is prolonged ; the eggs are
found at Plymouth from the end of January until the end of
April or even later ; at St. Andrews they have been taken from
April to July, and on the west of Ireland they were observed
in March, April, May, and June.

The ege of the sprat (Fis. 86) is from “9o4 to 1:2: mm. in
diameter (a little more or less than =; inch):' It is. to be
recognised by the division of the yolk into separate portions,

166 MARKETABLE BRITISH MARINE FISHES

which appear under the microscope as though separated by fine
lines. The whole egg is extremely transparent. There is no oil
globule, and the space within the egg-membrane is small.

The egg develops and hatches in a very short time, namely,

Fic. 86.—Egg of the Sprat, alive, magnified.

three or fourdays. The length of the larva or young sprat when
first hatched is 3:0 to 3°7 mm. (,13, inch to 745, inch). As may be
seen in Fig. 87, it is by no means so far developed as the newly

kao
STF

COAN Siraianueaaniaanaad

Fic. 87.—Newly-hatched larva of the Sprat, alive, magnified.

hatched herring, the mouth not being open, and the eyes being un-
pigmented. It is very transparent, and there are only a few minute
black specks on the body. The position of the vent near the end
of the tail is the same as in the other members of the family.

THE HERRING FAMILY 167

The transformation of the sprat larva into the perfect, fully-
developed sprat has not been carefully studied, but it is known
to resemble closely that of other fish of the herring family. But
concerning the growth and general history of the young we have
a considerable amount of evidence. The interesting observations
of Ewart and Matthews on Thames whitebait, already used in
connection with the herring, contain equally valuable information
concerning the young of the sprat. The condition and pro-
portional numbers of these are shown in the following table :—

Month | | Gites | or Gee. Length of Sprats.
| February . 1,400 93 2 to 3 inches.
iViarch s:|" 1,200 95 2 to 24 inches.
[evra eee 800 86 2 inches average.
INIER Oe chaeae 600 70 2+ inches.
|/itveve Gosese Soo 13 I to 2} inches, the smaller without scales.
| Wftbys “Seaene 600 2 | 8 per cent. of the Sprats under 13 inch |
| | without scales.
August ... 500 48 | x to 13 inch.

The number of small scaleless sprats gradually increased
during the last month, until 90 per cent. of the samples con-
sisted of these. This shows that the new brood of the year
began to appear in June, and increased to the end of August.
The transformation was completed when the fish were 1} inch
long. We have no direct observations of the period of spawning
at the mouth of the Thames, but may infer that it extended from
March to June, the fish being first caught when about two months
old. We see therefore that the little sprats 2 to 3 inches long
taken at the beginning of the season in February, March, April,
and May, were just about a year old.

The smallest ripe or nearly ripe sprats seen by Matthews in
the Firth of Forth were 4 to 44 inches long, and here again it is
probable that this length and the commencement of sexual
maturity is not reached before two years of age.

Young sprats fully developed, known locally as “britt,’ are
exceedingly abundant at Plymouth and other places on the south
coast of England, and are greedily devoured by mackerel, other
fishes, and sea-birds. They are commonly seen in summer time.
I have examined specimens in November 2°2 to 2°6 inches long.
In December I saw a large number killed in Millbay Docks by

168 MARKETABLE BRITISH MARINE FISHES

submarine blasting ; these were 2'2 to 2°4 inches in length. In
April specimens obtained outside the Breakwater were 3°3 to 3°8
inches long. The latter were doubtless a year old or a little over,
the others a month or two younger. The summer britt appears
to include the sprat fry of two years. I have not examined it
carefully myself, but, according to Day, the little sprats in August
at Dawlish were ? inch to 24 inches long. Those of the latter
size could scarcely have been hatched in the preceding spawning
season, even in January, while the smallest are evidently the young
of the year, hatched in the preceding spawning period.

Migrations.—It is evident from the above account that the
young sprats after hatching approach the shore and enter bays,
the mouths of rivers,and even docks. The britt less than one year
old are abundant and conspicuous in inshore waters all summer
and autumn, and remain there during the following winter and
summer. But the older sprats which are sexually mature are
only caught in autumn and winter on the south coast. The
obvious meaning of this is that they migrate seawards during
the spawning period, and regularly return towards brackish
waters afterwards. Thus from the Thames to Torquay the
principal sprat fishery is from October to the end of January.
The sprat fishing for full-grown sprats in the Firth of Forth
takes place in December, January, and February. It would
appear however that the mature sprats do not return towards
the shore immediately after the spawning period, since at
Plymouth that period seems to terminate in May, and there is no
sprat fishing until the following September at earliest. There is
room for further inquiry as to the position of adult sprats
in summer after spawning, and their food at that time and
during the early part of winter when they are captured in
inshore waters.

The Pilchard or Sardine. (C/upea pilchardus.)

Distinguishing Characters—Dorsal fin nearer to the snout
than to the root of the tail; pelvic fin behind the commence-
ment of the dorsal; last two rays of the ventral fin slightly
prolonged. Teeth in the jaws very minute or absent, none on
the tongue or palate. Radiating lines on the opercular bone,

es eS

THE HERRING FAMILY 169

and beneath the eye. Upper jaw reaching back to the front
third of the eye. Scales larger than in any other British species
of the family, only thirty in the whole length of the body, easily
detached. Spines on the edge of the belly weak, and the edge
itself rounded ; the whole form of the body is rounder than
in herring or sprat, and not so deep. Colour on the back olive
green, rather deep, Sides silvery. Does not often exceed 11
inches in length, and 8 or 9 inches is the usual size. Mr. Dunn
has seen a specimen 14 inches long, but this a rarity.

There is no difficulty in distinguishing the fully-developed
pilchard at any size ; it more resembles the shads than the sprat
or herring, but is easily distinguished from the former by the
more slender body, larger scales, and weaker ventral spines.
The question whether pilchards and sardines are the same
or not is frequently raised, and the correct reply to it is the
following. The sardine of commerce is prepared on the west
coast of France from Brest southward to La Rochelle, and there-
fore the fish is taken in a part of the sea which is near to, and
not separated from, that where the Cornish pilchard fishery is
carried on. The pilchard extends throughout both these parts
of the sea, and the sardine is not a different fish. Pilchard is the
Cornish name for it, sardine the French. But the fish which
are preserved in oil and tinned are small, young fish, from about
5 inches to 63 or 7 inches in length, and these are not regularly
caught by the Cornishmen. The difference in the product is due
to the difference in the mesh of the nets used. On the other hand
full-grown pilchards 8 to 10 or 11 inches long occur on the French
grounds, and are fished there in winter ; they are distinguished
as sardines de dérive which means drift sardines, sardines caught
by drifting with the nets without bait, while the small fish of the
summer fishery are called sardines de rogue, because salted cod’s
roe, called vogue, is scattered in the water as a bait to attract the
fish before the nets are shot. Nets of various meshes are used
in this fishery, and the fishermen use the mesh which is the right
size for the fish present at the time. Seines however have come
into, use. im the summer fishery in recent years. There is*no
reason to doubt that the small sardines could be caught in
Cornish waters: in fact they have frequently been taken in the
seines there, but were not wanted because not suited to the
Cornish trade.

170 MARKETABLE BRITISH MARINE FISHES

The sardine occurs also in the Mediterranean, and there, at
Marseilles, for instance, it is a smaller fish when adult and mature,
not exceeding 7} inches. But the sardine industry, the business
of tinning sardines in oil, is not carried on apparently on the
coasts of the Mediterranean, or if so has by no means such an
importance as on the west coast of France.

Flabitat——As already mentioned the pilchard extends through-
out the Mediterranean, but is a smaller race, just as plaice are
smaller in the Baltic than in the North Sea. The oceanic
sardine or pilchard extends from the southern shores of England
and Ireland to Madeira. There is no great fishery for these fish
on the south and south-west coasts of Ireland, although large
numbers are sometimes taken near Cork, and the fish are
abundant on these coasts. On the other coasts of Ireland or
Britain the fish are only ocasionally taken in small numbers.
The regular productive fishery does not extend eastward of the
Bill of Portland, nor north of St. George’s Channel. The distance
to which the fish wander from the coast it is not at present
possible to estimate with much accuracy. They are said to be
seen at times fifty miles from the Scilly Islands.

Lreeding.— According to Day, the number of eggs is about
60,000.

The relations between the breeding of the fish and its capture
are in the pilchard exactly the reverse of those which exist in
the case of the herring. Among the pilchards caught for the
market it is a rare occurrence to find any which are in a gravid
condition. When pilchards caught in the ordinary course of the
fishery are opened, their generative organs are usually found
to be small and undeveloped; the process of spawning has
either been xsecently completed, or the ovaries “and testes
have scarcely begun to enlarge in preparation for the next
period of reproduction. In fact ripe pilchards do not form
the object of a regular fishery. In my own experience I have
seldom known ripe pilchards to be caught in a pilchard net.
They are usually taken accidentally by nets intended for other
fish ; most of those that I have seen were captured in mackerel
nets. The explanation of this lies of course in the habits of the
fish. Ripe pilchards are usually only met with at a considerable
distance from land, twenty to forty miles out to sea. Pilchard
nets, whether drift-nets or seines, are usually shot near the shore,

THE HERRING FAMILY WA AI

the drift-net boats seldom go much further than ten miles out.
The ripe pilchards are taken in small numbers in mackerel nets
in summer and early autumn. Possibly if pilchard nets were
habitually used at the proper places and time of year ripe
pilchards would be taken in large numbers, but the meshes of
mackerel nets are much too large to catch pilchards in the
ordinary way, the few that are retained by the meshes are caught
not behind the gills, as fish usually are in a dift-net, but round
the abdomen, which is swollen by the enlarged ovaries. As far
as my own experience goes only the females are caught in this
way, and I was for a long time unable to obtain a ripe male
pilchard. Probably the ripe males are not distended so much as
the females, and therefore pass through the meshes of the
mackerel nets without being retained. Probably, too, only the
largest females are caught. The number taken in a fleet of
mackerel nets at one time varies from one or two to fifty or
more, but scarcely ever exceeds a hundred. The time at which
they are taken is not limited to a few weeks, but extends from
the beginning of June to the end of October; they are
commonest in July and August.

The eggs of the pilchard when shed are not heavy and adhe-
sive like those of the herring, but float about separately in the
sea, like those of the sprat and anchovy. As early as 1865
Couch stated in his work on British fishes that he had reason
to suppose that the spawn of the pilchard was shed at the sur-
face, and floated in a quantity of tenacious mucus, but he gave
no satisfactory evidence on the subject. Mr. Dunn informed
the Commissioners for Sea Fisheries, in 1879, that he had
pressed ripe spawn from a female pilchard in May, 1871, and
that the eggs floated separately in a bucket of sea-water. But
no microscopic examination of the egg was made till many
years afterwards. In 1888 Raffaele, an Italian zoologist, de-
scribed among the eggs he found floating in the sea one which
evidently belonged to some fish of the herring family, and which
he thought probably belonged to the sardine. Not long after |
began to work at Plymouth I obtained from the open sea a
buoyant egg similar to that described by Raffaele, and found
that the ripe unfertilised eggs squeezed from female pilchards
had the peculiarities in the condition of the yolk seen in this

egg, and in no other egg hitherto examined from our seas.

172 MARKETABLE BRITISH MARINE FISHES

It was not till 1893 that I succeeded in obtaining artificially
fertilised eggs of the pilchard. These were taken on September
5th, ten miles south of the Eddystone, by the crew of a boat to
whom I had given bottles for carrying the eggs and instructions
for handling them. In this case the boat was using pilchard
nets and fishing for pilchards, but was working farther from the
coast than usual. In the catch of 2,200 fish a few ripe specimens
were found, and the eggs were brought to me next morning in
good condition and in process of development. The eggs agreed
perfectly with those previously obtained from the sea.

Fic. 88.—Egg of the Pilchard, alive, and magnified.

The appearance when magnified of the living pilchard egg in
course of development is shown in Fig. 88. The egg is com-
pletely distinguished from the numerous other kinds which float
in the sea by three unmistakable peculiarities. These are (1) the
unusually large space between the egg-membrane and the
enclosed egg, (2) the complete division of the yolk into a num-
ber of irregularly-shaped segments, (3) the presence of a single
large oil-globule in the yolk. Neither of these characters alone
is peculiar to the pilchard egg, but no other egg is known in
British waters which possesses the three together.

Pilchard eggs are taken in small numbers when the tow-net

THE HERRING FAMILY 173

is worked even a short distance from land in summer, but be-
come more numerous farther out to sea. If the eggs are kept a
few days in clean sea-water they hatch, and the larval fish that
issues from them has the structure shown in Fig. 89. The artifi-
cially fertilised eggs mentioned above hatched in three days at a

Fic. 89.—Newly-hatched larva of the Pilchard, alive, and magnified.

temperature of 62°. The larva is 3°38 mm. long (slightly over
=; inch). The yolk is still large, the oil-globule at the hinder
end of it, the mouth is not open, and there is no pigment except
a few black specks along the back of the slender body. The
mouth appeared on the third day after hatching, and on the
fourth day the jaws were developed, the eyes were black, and the
yolk almost all gone. On the fifth day I put some of the minute
creatures gathered from the sea by the tow-net into the tank
containing the larva, and also some minute particles of minced
sea worms, and they began to feed. When five days old the
larve were over 1 inch long, and the yolk was all gone.
When feeding the larve were seen to peck or strike at the par-
ticles which they swallowed, so that feeding is a deliberate and

SOE
BL CITI ili tlit ry

Sige

Fic. 90.—Larva of the Pilchard, nine days old, alive, magnified.

active, not a passive, involuntary process. Fig. 90 shows the
appearance of one of the larvae when nine days old.

The transformation stages of the pilchard have been traced
by me in specimens captured at sea near Plymouth. The speci-
mens were taken at the surface at night, in a large tow-net made

174

MARKETABLE BRITISH MARINE FISHES

N

SSS

Uf

(to,

=i

FIG. 91.

=

PDPDDINEDs

TL

MELT 1 0 1 DDD
ot ene

SPT OTN,

tat

tones ary
oN

, after preservation in spirit.

g1.—Larva of Pilchard at commencement of transformation

92.—Older stage of Pilchard larva, after preservation.

Fic.
Fic.

of mosquito netting.
They very closely re-
semble the similar
stages of the herring
or sprat, and the
starting-point of the
reasoning which leads
to the conclusion that
they are pilchards is
the time of year at
which they were
taken. There are no
herrings spawning in
the neighbourhood of
Plymouth in June or
July, and sprat eggs
are not usually seen
there later than the
beginning of May;
pilchard eggs on the
other hand are abun-
dant from the begin-
ning of June to late
autumn. The young-
est stage of the speci-
mens Inj (question:
moreover, was smaller
than the herring at
an earlier stage of
development.

The youngest of
the specimens was
ome gvabada. levator (ee
inch). It was but
slightly advanced be-
yond the condition of
the oldest larva reared
in confinement. The
chief differences were
that the fin mem-

THE HERRING FAMILY 175

brane had disappeared along the belly in front of the vent, and
was much narrower behind the vent and along the back; the
tail was more distinct and more developed, and the dorsal fin
had begun to appear on the back. In an older stage (Fig.
QI), 11°5 mm. in length (44% inch), the dorsal fin was larger,
and the tail more developed, but traces of the original fin
membrane remained, and the hinder pair of side fins had not
appeared. The largest specimens (Fig. 92) were 24 mm. long,
or very nearly one inch, and in these the body was thicker,
and the fin-rays much better developed ; the original fin mem-
brane was entirely gone, the tail was forked and like that of the
adult, and the hinder pair of side fins were present. But the
dorsal fin was still behind the hinder side fins; there were no
scales or silvery coat, and the body was very long in proportion
to its thickness.

At Marseilles and Nice, on the shores of the Mediterranean,
very fine nets are used for the capture of swarms of minute fish
fry, very much as in the whitebait fishing of England. In the
Gulf of Marseilles, Professor Marion has traced the growth and
development of the pilchard in the produce of such fishing
throughout the first year of its life. The young sardines before
the development of the scales and silvery covering are called by
the fishermen foutzno nudo, or naked fry ; these are from # inch
to 12 inch. At a larger size, 12 to 2 inches, when they have
acquired the silvery livery, they are called poutzno vestido, or
clothed fry. When still larger they are called palazlla and
sardinettes.

It has been abundantly established that the small pilchards
taken on the west coast of France for the sardine industry are a
year old, and are sexually immature. That they are not capable
of spawning is certain, no development of the roe or milt having
ever been seen in pilchards of this size. With regard to the age
we have merely to assume that the fish spawns in the neigh-
bourhood of the French coast in summer and autumn as it does
on the English coast, or rather it may be said that we know that
in the area of sea about the entrance of the English Channel
the pilchard spawns from June to October. Therefore it is
certain that the small fish which appear from May onwards are
the produce of the preceding year; we have no reason to sup-
pose that they are more than one year old. These fish are from

176 MARKETABLE BRITISH MARINE FISHES

five to seven inches long, and there is no regular succession of
sizes as the season advances. The latter fact is not surprising
when we consider the long spawning period, and the rapid
movements of the shoals. Early in the season, in May, for
instance, the fish caught may be those which were hatched in
the early part of the preceding season, while in the next month
shoals may appear which were hatched in September or October,
and are therefore very much smaller. At the same time it has
been observed that the sardines of the latter end of the season
are larger on the average than at the beginning. The facts here
mentioned concerning French waters are obtained from the
observations of the late Professor Pouchet, who studied the
natural history of the sardine at Concarneau on the coast of
Brittany. In the years 1887 to 1890 there was a serious crisis
in the sardine industry of France, the fish having failed to
appear on the coast in their usual abundance. The Government
were anxious, as usual in such a case, to obtain as much accurate
information as possible from scientific men, concerning the life,
reproduction, and history of the fish, and Professor Pouchet on
the west coast and Professor Marion at Marseilles endeavoured
to obtain the information, which as usual was not available and
not energetically sought until a special demand arose. The
Cornish industry has recently suffered from a depression caused
more by the failure of the market than of the supply of fish.
The natural history of the pilchard was investigated at Plymouth
from 1889 to 1894, and the credit of having carried the inquiries
to a successful conclusion and solved the problems which in
France were declared to be insoluble in the immediate neigh-
bourhood of the coast, belongs to the Plymouth Laboratory.
Hitherto naturalists have not had the opportunity of studying
the occurrence of yearling pilchards on the coasts of Devon and
Cornwall in summer time, although there is every reason to
believe that they occur there in numbers. But at the end of
1891 a fleet of small-meshed nets, intended to capture anchovies,
was shot frequently, and took considerable numbers of small
pilchards. These were taken in November and December in
numbers varying from 8 to 500. Their lengths were from 5 to
+ inches. With them were taken others larger and older. The
small fish must have been just over a year old, hatched late in
the preceding season.

THE HERRING FAMILY WIE!

We have now to consider what is known concerning the
history of the pilchard between its transformation to the perfect
form in one summer, and its appearance as yearling fish the
next. Mr. Dunn long ago observed that small pilchards 2 to 3
inches long were to be found on the coast between September
and Christmas. He had seen them taken in a mackerel seine in
September, and had found them in the stomachs of whiting, In
November, 1891, I found them in the stomachs of mackerel ;
they were from 2 to 34 inches long, some of them less than
2 inches. These mackerel were caught outside the Eddystone.
But in September, 1893, I found that pilchard fry were not
found only in the open sea at some distance in the offing. I had
an opportunity of examining in that month the fish caught by
seine in the Hamoaze, opposite Devonport. The greatest part
of the catch consisted of full-grown sprats, but there was also a
large quantity of small fish of the character of whitebait. These
consisted mostly of young sprats, 2} to 34 inches long, but
among them were a small proportion of young pilchards, 23 to
42 inches long. These were probably derived from spawn shed
in May or June.

The growth of the pilchard in its second year is of course
more difficult to trace. It seems reasonable to suppose that the
fish which are 5 to 7 inches long in November, or earlier in
August and September, would reach a length of 8 to 10 inches
in the following summer, and then spawn for the first time.
The only ripe pilchards I have measured were from 92 to 10
inches long, but considering that these were taken in mackerel
nets, the mesh of which is large, it is probable that many fish
spawn at a smaller size. I have examined specimens from the
regular fishing in August, these were from 82 to 10 inches long,
and even in the smallest the roes appeared to be shotten, to
have discharged their eggs quite recently. We may conclude
therefore that some pilchards spawn in their second season when
they are about 8 inches long. The weight of a ripe female
is 5 to 5? ounces.

178 MARKETABLE BRITISH MARINE FISHES

The Shads.
Allis Shad (C/upea alosa) and Twait Shad (C/upea finta).

Distinguishing Characters—Dorsal commences nearer to the
end of the snout than to the root of the tail ; pelvic fin behind
the commencement of the dorsal. Radiating lines on the gill-
cover and beneath the eye. Teeth minute and easily detached
in both jaws, none on the palate or tongue. The upper jaw
deeply notched in the centre, and reaching back farther than the
hinder edge of the eye. Scales smaller than in the pilchard ;
spines on the edge of the belly strong and sharp.

In the allis shad the gill rakers on the lower portion of the
first gill arch are long and sixty to eighty in number ; in the
twait shad they are thicker and shorter, twenty to twenty-eight
in number. Spots along the upper part of the side, from the
upper corner of the gill-cover backwards, are present in both
species, but in the allis shad disappear in the larger and older
fish.

The allis shad is said to reach 4 feet in length and 8 lbs. in
weight, but 2 feet long is its usual limit. The twait shad grows
to 16 inches and 2 lbs. in weight.

Habitat—These are coast fishes, which ascend rivers in
order to spawn, and are not taken usually in large shoals in the
sea, though as many as 600 of the allis shad have been taken
in a mackerel seine. The allis shad is said to be absent from
Sweden, and is not mentioned as occurring in the Mediterranean.
The twait shad is abundant in the Nile, and elsewhere in the
Mediterranean, and occurs on the Atlantic coast northward to
Scandinavia. Both species occur in the Severn, and along the
south coast of England, also along the east coast to the Firth of
Forth and Banff. They occur round the coasts of Ireland.

Food.—From the form of the gill-rakers, and from occasional
examination of the contents of the stomach, it appears that
they often subsist on minute crustacea, but frequently when
they have the opportunity they feed on small fishes, especially
young sprats, which were found in the stomachs of eight
specimens of the allis shad taken in Plymouth Sound in
August.

THE HERRING FAMILY 179

Breeding.—The time of their ascent up the rivers is men-
tioned in Day’s Bretzsh Fishes, namely, from about the middle
of April in the Severn for the twait shad, May to the middle of
June for the allis.

But no scientific study of the eggs or the development or
history of the young has been made in Britain or Ireland. For
accurate information we are indebted to observations made in
France and Germany. At Elbceuf, on the Seine, twelve miles
above Rouen, there is a hatchery for the artificial propagation of
these fish, and it was there that Professor Pouchet studied the
eggs in 1889. The eggs of the two species are very similar to
one another. They are heavier than the fresh water in which
they develop, and therefore sink, but unlike herrings’ egg they
are not adhesive. They remain free and separate at the bottom
of the river, carried down by the stream, or back again by the
tide. They are spawned in May and June.

With regard to the structure of the egg it resembles that of
the pilchard without the oil globule. The yolk is subdivided,
and there is a large space between it and the egg membrane.
fies latte; in the twait shad measures. about 475 -mim:. or
nearly 348, inch, while the yolk is only 1°75 mm. or z%> inch.
The eggs at a temperature of 66° hatched on the fourth day
after fertilisation.

The eggs of the American shad (Clupea sapidissima) are
hatched annually in millions by the United States Fish Com-
mission, and the fish now seems to be almost as completely a
product of cultivation as the oyster is with us. The eggs are
shed in fresh water, in which they sink, but remain free and
separate. The egg membrane is about ,2, inch in diameter,
the contained egg being about half as wide. The yolk is
divided and without oil globule, so that the resemblance
to the egg of the European shads is very close.

Recently a careful study of the twait shad in the Elbe has
been made by Ehrenbaum,a German naturalist. He found that
this species spawned near the mouth of the river, just above the
brackish water, below Hamburg, while the allis shad ascends in
the Rhine to spawn as far as Basle, and in the Elbe above
Dresden. The spawning took place only at night, and the fish
rush about during the process so as to make a swishing noise in
the water. The egg of the twait shad when first shed before the

N 2

180 MARKETABLE BRITISH MARINE FISHES

separation of the membrane was 1°5 to 1°6 mm. (7%, inch), but
after the swelling of the membrane its breadth was 42 to 46
mm. (35°5 inch).

The newly-hatched larva is just over 3%, inch long. It is
extremely transparent, and has no mouth and very little pig-
ment, so that it resembles that of the sprat. Ehrenbaum was
able to trace its transformation to the fully developed form, and

its history, with considerable completeness.

Fic. 93.—Larva of the Twait Shad, nearly 2 inch long ; after Ehrenbaum.

The eggs naturally deposited were obtained from the bottom
at the end of May by sinking a fine-meshed tow-net. They
were quite free, but being so transparent were not easy to find
among the rubbish, consisting of fragments of plants, among
which they were taken. The larve in various stdees were
captured in the same manner. When 8 to 9 mm. (,5; to 5°; inch)
long the yolk was nearly all gone, the mouth well ieee
and the fin membrane narrow. But the permanent fin rays had
not appeared. In June larva were obtained which were 13 to

SS aes
as

A= 3

naa ie wid rs VUE aL Te

Fic. 94.—Larva of the Twait Shad, # inch long ; after Ehrenbaum.

15 mm. long (Fig. 93), and in these the dorsal and ventral fin
rays had just begun to appear, but the fish was still slender and
transparent and the snout rounded. At the end of June speci-
mens 16 to 20 mm. long were taken: in these the forked tail
and the fins were more fully developed, and the head was more
like that of the adult, but the scales were still absent (Fig. 94).
These larve were feeding on minute crustacea.

On July 6th specimens were obtained which were 24 to 29

THE HERRING FAMILY 181

mm. in length, or from a little less to little more than an inch,
and which had advanced further in their transformation. The
head, and especially the gill cover and also the abdomen, began
to show the silvery coating of the fully developed fish, and the
pigment of the back was considerably increased ; but the body
was still very slender and narrow, decreasing rapidly from the
head backwards. The dorsal fin was still behind the hinder
side fin in position. By the middle of July young shad, whose
transformation was practically complete, were found to be
captured in the s¢ow-nets, having now become thick enough to
be retained by its meshes. These were 36 to 46 mm. long, or
from 1% to very nearly 2 inches. Their body was almost com-
pletely silvered, and the scales developed nearly everywhere, the
keeled scales of the belly being well formed. The dorsal fin was
now in front of the pelvic, and in some specimens the dark spot
on the shoulder was visible. It would appear from this that the
transformation of the twait shad is a little more rapid than that
of the spring herring in the Schlei; and that the fish at the com-
pletion of the process are on the average somewhat shorter than
the herring, although the difference is not great.

Young shad from the stow-nets were examined and measured
by Ehrenbaum at brief intervals from July onwards, and the
following records show the rate of growth :—

fully; BOs, kek \e} Goad soanabdeonaasdecutbe 1°8 —2°8 inches.
JANTUIRAUISIE THOS | TSP) os dobpadoastoeonoonc 1°68—2'52 ,,
/AYMEEANIC LE” IES, itsKO lll sgangocbeeon tos ace" NN) 2708 ——3°52) 5,
ANMIERUISE 17/5 TUS{OR 5, lace don. casnassoonee 2°16—3'24 ,,
September 2Oy TOOB™ eee ee et 2°88—4'88 __,,
OctohbersOymisSome sees. sekeeceees- 2°76—3'44 ,,
OctohershseLsO lm eee seis) | SkOO—31OO) 5,
November 15 .elSOlsseessas-cecee 372 —4'96__,,

Records of the number and length of young shads captured in
the stow-nets at the mouth of the Meuse in Holland have been
published in Dutch fishery journals. To summarise these records,
with regard to the twait shad, in the month of October eighty-
two specimens were taken, the smallest 2°16 inches long, the
largest 6 inches, but the majority 3 to 4 inches. These may be
considered the produce of the previous spawning season. In
April ninety-three specimens measured 3°56 to 3°68 inches.
This shows that some specimens nearly a year old are scarcely
bigger than others at five or six months. In June thirty-one

182 MARKETABLE BRITISH MARINE FISHES

specimens were 3 inches to 5 inches. But these results appear
to show only the under-sized specimens at one year of age;
there must be others from 5 to 7 inches.

Of the allis shad the October specimens, 104 in number, were
2°32 to 5°72 inches, the majority at any rate being fish of the
year ; the June specimens, twenty-three in number, were 3°84 to
to 5°44. The latter must have been a year old, but must also
have been very much stunted in growth. The meaning of these
results is probably that the young shad, reaching in the case of
the twait 3 to 5 inches in November, for the most part leave the
river then and do not return until two years of age when they
spawn for the first time, and that the few specimens found in
the river in their second summer are stunted in growth. In
this, as in other cases, more complete evidence is still required.

The Anchovy. (Lugraulis encrasicholus.)

Distinguishing Characters—Head terminating in a fleshy
pointed snout which projects beyond the jaws ; gape of mouth
very deep, reaching back far behind the eye. Body slender and
elongated, belly rounded without spines on the edge. Scales
rather large, easily detached ; skin soft and easily torn. Pelvic
fins considerably in front of the dorsal, teeth in both jaws, very
fine in the lower; also present on the palate. Colour dark
greenish along the back, silvery on the sides and belly. The
maximum length is 8} inches, the majority are 5 to 7 inches.

FHlabitat—Extends throughout the Mediterranean, and along
the Atlantic coast of Europe northward to Norway, where,
however, it is only taken in small numbers. In winter it is
common though not very abundant in the western part of the
English Channel, while it has been recorded from the Wash and
other places on the east coast in summer. It has been taken in
June off Southport in Lancashire, and is sometimes common off
Swansea. It has also been occasionally taken on the Irish
coasts. In Holland there is a regular and somewhat valuable
fishery for anchovies, which is carried on in summer both in the
Zuyder Zee and in the estuary of the Schelde. Three methods
are employed in these shallow waters for taking the fish, namely,
the moored net, a kind of stake net, and a kind of sweep-net.

THE HERRING FAMILY 183

The moored net is like a small drift-net ; it is about four feet in
depth, of considerable length, having the ends stretched on
poles. The top line is corked and the bottom line leaded, and
the net is fixed by small anchors attached to the poles. The
second apparatus is used near Bergen-op-Zoom, and consists of
fences, constructed of willow and poplar branches, which lead to
gaps at which nets are placed. The sweep-net is a large bag-net
dragged along by two boats, each towing one end of the mouth.
In France, Spain, and Italy both drift-nets and seines are used
for the capture of anchovies, in the usual manner, as for
mackerel and herrings.

Breeding. — The anchovy spawns
regularly every year on the coast of
Elolland:) im) the Zuyder’ Zee’ and’ the
neighbouring sea, and also in the Medi-
terranean. Its eggs and development
were first investigated in the Zuyder
Zee by a Dutch naturalist. The spawn-
ing takes place in June and July. The
eggs are buoyant and transparent, but
they are unique in shape. Alone among
the buoyant marine eggs at present
known they are not globular or nearly
so, but elongated, sausage-shaped, about
z30 inch long and 7%, inch broad (1:2
Mi eiieleisth a7) mime, in) breadth). 4

j 3 Fic. 95.—Egg of the An-
(Fig. 95). Nevertheless, the egg shows chovy, alive, and magni-
its affinity or relationship to those of the __ fied after Wenckebach,
pilchard and sprat, having the yolk com-
posed of separate masses as in these ; it resembles the eggs of
sprat and shads in having no oil globule. The eggs have also
been obtained in the Bay of Naples, where the spawning period
is from May to September. The development of the eggs lasts
two or three days at a temperature of about 60° to 64°. The
newly-hatched larva (Fig. 96) is a little over 2 mm. long
(3; inch), very transparent, with scarcely any pigment, but
distinguished from those of other members of the family by
the elongation of the yolk. The latter extends from the head
nearly to the vent, becoming narrower behind. The mouth is
as usual unformed. Thirty hours after hatching the larva is

184 MARKETABLE BRITISH MARINE FISHES

3,6 mm. long (4445 inch), the yolk is much diminished, and the

mouth open beneath the head. On the fourth or fifth days the
jaws are fully formed, the yolk exhausted, and the larva begins
to feed.

The transformation of the larva has not been very carefully
described or figured ; in fact, it has not been distinguished with
sufficient certainty from the larve of other fishes of the family.
However, larve identified as those of the anchovy were taken
July 27th to 31st in the Zuyder Zee; their lengths were 16 to
30 mm. (2 to 14 inch).

It has been recorded that young anchovies were taken in the
Zuyder Zee in August, which ranged in length from 1°3 inch to
32 inches. In September fifty-two specimens were obtained rang-
ing from 2 inches to 4 inches in length; in October thirty-three

BEE ON ET Ee TELIA A AY a a
{ FE CO j.

megese
os

Fic, 96.—Larva of the Anchovy, newly-hatched, alive, and magnified ; after
Wenckebach.

specimens 3 inches to 44 inches. It is impossible, unless we had
direct evidence that the growth of the anchovy was unusually
rapid, to suppose that these specimens were derived from spawn
hatched in June and July. The length of the smallest anchovies
present in May and June is not stated. We may consider the
above specimens as corresponding to pilchards of about 5 inches,
and to be the year-old fish. The average length of the mature
anchovy is 15 cm. or 6 inches, and the smallest 5+ inches, a size
probably reached as in other cases in two years.

We do not know yet the history of the younger anchovies
after they are hatched in the Zuyder Zee in June and July.
They apparently leave that place in autumn, and return with
the full-grown fish the following summer. We have now to
consider the migrations of the adults, and see how much remains
mysterious in the history of these fish.

THE HERRING FAMILY 185

It has long been known that anchovies occur with great
regularity, but in varying abundance, off the coasts of Devon and
Cornwall in the last months of the year. For several years
observations on the occurrence of these fish were made by myself
and others at the Plymouth Laboratory, and a fleet of small-
meshed nets was procured and shot on purpose to catch them.
They are usually most in evidence in November. In 1889 a con-
siderable number were taken by the sprat fishermen, fishing with
drift nets, off Dover, then they were taken in the sprat seines in
Torbay. They continued to be captured till the beginning of
January at Torquay. In November, 1890, a thousand of the
fish were obtained from the pilchard boats off Plymouth in two
days. These facts seem to indicate very strongly that the
anchovies leave the coast of Holland in October, and migrate
down the English Channel. It would follow that they return
to Holland about April. But although a few have been taken
by the small-meshed nets off Plymouth in April, they have
not yet been found to be so abundant at that time as in
November. No indication that any anchovies are present near
Plymouth in summer, or that they spawn there, has ever been
obtained. It appears then that they move northwards to
spawn.

But then the question arises, If the anchovies move north-
ward to spawn, why do not others come up from the Bay of
Biscay to spawn in the English Channel? The reply to this
apparently is because the shallow enclosed waters of the coast
of Holland are much warmer in summer than the waters of the
English Channel, and colder in winter. In July, 1891, the mean
temperature off Plymouth was 57°3°; in the same month in the
Zuyder Zee it was 62°7°. In February, 1892, off Plymouth it
was 45°1°; in the Zuyder Zee in the same month 36°. Thus the
anchovies are driven south by the cold, and in summer by going
to the Zuyder Zee they get water as warm, as it is farther south
in the Bay of Biscay, where also anchovies probably spawn ; but
we do not know the latter fact by actual observation at present.

So far as comparisons have been made at present, evidence
of abundance of anchovies in the Channel in November is
followed by a large catch in the Zuyder Zee in the following
summer. Buta small catch in the Zuyder Zee has not always
been followed by a scarcity in the Channel. The two years

186 MARKETABLE BRITISH MARINE FISHES

when these fish were most abundant in the Channel were 1889
and 1890. In the summer of the former year the catch in the
Zuyder Zee was one of the smallest, in the latter year it was the
largest ever known, and in 1891 it was also large. The question
therefore arises whether the number of anchovies which pass up
to Holland have all been hatched there, or whether they are
recruited from the south; that is to say, whether a mild winter
allures the anchovies northwards towards the Channel, and they
then with the approach of summer pass northwards instead of
southwards to spawn. Then again it is possible that the fish
may be very abundant off the coast of Holland but not enter
the Zuyder Zee.

GHEE SALMON FAMTECY

THE fishes of this family are distinguished by having two
dorsal fins of which the foremost is situated near the middle of
the back and supported as usual by fin-rays, while the hinder,
placed above the ventral fin, is small and imperfect, having no
fin-rays. There is a peculiarity in the internal structure of
these fishes, which occurs also in the eels, namely, that the roe
in the female is not a closed sac, but is as it were split open,
so that the eggs when they are ripe become free in the belly
cavity before they escape by an opening behind the vent.
Different fishes of the family show a great diversity of habit.
With one exception in New Zealand all the species are confined
to regions north of the tropics, but within this part of the globe
some live entirely in fresh water, some feed in the sea and spawn
in rivers, while a few live always in the sea, some of these
belonging to the abyssal depths of the ocean. In Britain the
grayling and river trout, and the pollan, vendace, &c., of the
large lakes are the fresh-water forms, the salmon and sea-trout
the migratory. The eggs of all these are of considerable size,
and are heavy and non-adhesive ; they are buried by the parent
fish in the gravel bottoms of rivers or lakes. The smelt lives at
the mouths of tidal rivers, and spawns in fresh water some miles
from the sea. Only one marine species of the family occurs off
British and Irish coasts, namely, the argentine, which has been
frequently taken at depths of 30 to 500 fathoms off the west
coasts of Ireland and Scotland. As this fish is of no commercial
importance, and scarcely anything is known of its habits, and as
the species that spawn in inland waters are outside the scope of
the present work, the history of the smelt alone will be here
considered.

188 MARKETABLE BRITISH MARINE FISHES

The Smelt. (Osmerus Eperlanus).

Distinguishing Characters —Body elongated, cleft of mouth
deep, the upper jaw reaching back to the hinder edge of the eye.
Enlarged fang-like teeth, as well as smaller ones on the palate
and tongue, ordinary teeth in the jaws. Scales of moderate
size. The tail fin forked. Colour of a light olive-green on the
back, silvery with iridescent colours on the sides and _ belly.
Along each side there is a specially distinct broad silvery
band, brighter than the rest of the side. Rarely exceeds
12 inches in length.

Habitat.—Mouths of rivers in Northern Europe and North
America. Itssouthern limit appearsto be the Seine, where itascends
as high as Rouen. It is found in the Thames and Medway, but
not on the south-west coast, e.g. Plymouth, where a fish belong-
ing to a different family is called the smelt. This is the sand
smelt or atherine, which has a close resemblance to the smelt in
external appearance. In the rivers of the east coast of England
the true smelt is plentiful, and regularly captured for the market.
It is found in the Forth and the Tay, the rivers entering the
Solway, the Dee, and the Mersey, but is not known to occur in
the rivers of Ireland.

food.—It feeds on small fish and crustacea.

Lreeding.—It spawns in March, April, and May, ascending to
near the limit of the rise of the tide, where the water is fresh or
very nearly so. In the Forth it spawns annually just below
Stirling, where I have taken the eggs and fertilised them artifici-
ally. More recently the development of the eggs and the history
of the young have been carefully studied by Ehrenbaum, a
German naturalist, in the Elbe below Hamburg.

The egg is heavy and adhesive, but it is attached to the stones
of the bottom, or to wharves and piles in the water, in a manner
different to that found in the case of the herring (Fig. 44, p. 93).
The egg membrane in the ripe egg consists of two. layers, and
when the egg is shed by the female fish the outer layer bursts
at one point and separates, remaining however connected with
the inner layer over one circular patch, in the centre of which
is the minute opening by which the sperm of the milt makes its
entrance into the egg. The loose outer membrane is sticky when

THE SALMON FAMILY 189

the egg is first shed, and attaches itself to the surface it touches
or falls upon, so that the egg remains suspended or anchored
by the flexible membrane. Ehrenbaum found however many
eggs quite free, having been evidently torn from their attachment,
and this seems to happen frequently in consequence of the force
of the tidalcurrents. In the Elbe the fine net used at the bottom
always brought up much rubbish, consisting of fragments of
water plants, and among this were the smelt eggs, some attached
to the fragments, some free.

After fertilisation a considerable space is formed between the
enclosing membrane and the body of the egg. The shape is
round and the breadth of the enclosing membrane varies from
‘9 to 1°3 mm. (about 745 to z%5 inch). The yolk is composed of
small globules, and contains several oil globules of different sizes.
The whole egg is fairly transparent, but less so than marine
buoyant eggs.

The development is rather slow and took at a temperature of
46° to 53° twenty-seven days. In the earlier part of the spawn-
ing season, from the end of March onwards, the water being
colder, the development would take longer. The newly hatched
larva is 5°55 to 6 mm. long (,%4 inch or a little less). The mouth
is already open, but beneath the head ; the yolk is much reduced,
and the oil globules all united into one which is situated near the
front end of the yolk sac. The primitive fin membrane is narrow,
the intestine ends near the end of the tail, far behind the yolk
sac as in the larve of the herring family. The pigment is very
scanty, there is some in the eyes and specks on the yolk sac and
along the lower edge of the body. The whole larva is very
delicate and transparent.

The larve were kept alive for fifteen days after hatching in
an aquarium. On the sixth day by the growth of the lower
jaw the mouth had become terminal and the yolk was nearly all
gone ; but the finshad not begun to appear (Fig. 97). Thelarva
at this age was 6°3 mm. long ( inch). The youngest larve
captured in the river were taken on the 5th to 8th May, were 6
to 8 mm. long (the largest nearly 4 inch), and had already begun
to feed on the minute crustacea, called copepods, the usual food
of young fishes. The larve were extremely abundant in the
estuary of the Elbe, a small net only 2 feet 8 inches across the
opening placed in the current for a quarter of an hour captured

190 MARKETABLE BRITISH MARINE FISHES

on one occasion on May 28th a number calculated to be 107,000.
These specimens were 14 to 20 mm. long (% to 4 inch) and were
still very transparent, but the first dorsal and the ventral fins had
appeared. These larve (Fig. 98) were still very slender in propor-
tion to their length, and were remarkable for the great size of
the air bladder. In the middle of June the little fish were + inch
to 15’; inch long, and had nearly reached the form and character
of the perfect smelt. They were still however transparent, and
without the scales and silvery coat.

Even in August the young smelts, now I,% inch to 14
inch, although more pigmented and less transparent, had not
acquired their scales and silvery garment. The development of
these last characters of the perfect fish takes place in Septem-

ber and October, when the young are 2 inches to 22 inches

97
; EIR IT I
eo) _ eo pmmammntntep Ge A
fe) ee ONAN UOT, frat (aveete teed leet SEER urTEI re < —
{ Wie OS Ss RSS
98

7, Yd
FEL PEE ETT A TOT =
CCC CT ECR Rr
Se SSN Ree =
. =

Peake SSS Bs CCUuKes ——
— RW SSS

Fic. 97.—Larva of the Smelt, + inch long, 6 days old ; after Ehrenbaum.
Fic. 98.—Larva of Smelt, # inch long ; after Ehrenbaum.

long. It will be seen from this that the transformation of the
young smelt is more delayed and more gradual than in the case
of the spring herring, whose change to the form and character of
the adult is completed in the Baltic at the end of July.

In August the multitudes of smelt fry of the year become
large enough to be caught by the large stow-nets (steerthanzen)
which are used in the Elbe. But these are employed not asa
delicacy for the table as whitebait is in London, but only as bait
for the eel traps.

After October the smelt, young and old, descend towards the
sea, and return towards fresh water at the end of February and in
March. Inthe Elbe Ehrenbaum found that while the smallest
ripe fish were 4 inches long, others which were as large as this
were immature. He also observed that in the first half of the

THE SALMON FAMILY IQI

summer, before the young of the year had got beyond the larval
stages, young immature smelt of 24 to 32 inchesin length were very
abundant, and also caught in very large numbers for eel bait.
This shows the usual growth of the year-old fish, some of which
spawn for the first time when two years old and 4 inches
to 6 inches long.

THE pA. BAwiiLy

THE fishes belonging to this family resemble one another in
the following particulars. The body is elongated and usually
round, though sometimes flattened from side to side ; it is always
flattened at the tail end. The vent is some distance behind the
head, and behind the vent is a long tail region becoming grad-
ually thinner. The dorsal and ventral fins are very long and
flexible, extending either to the extreme tip of the tail or right
round it, so that there is no distinction between them and the
tail fin. The pelvic or hinder side-fins are entirely wanting, the
breast-fins usually well developed. The skin is soft and extends
all over the head and gill covers ; there are no scales or only
rudimentary ones entirely imbedded in the skin. The body is
strong and muscular, and extremely flexible. The common eels
live in fresh water, but do not breed there ; there are several
marine forms found near the coasts like the conger, and a num-
ber of species inhabiting only the abysses of the ocean. The
members of the family are spread through all the tropical and
temperate zones, but absent in arctic and antarctic regions.

The mode of propagation of these fishes has always
been a mystery, but recently some light has been thrown upon
it although it is by no means fully explained. The roes whether
hard or soft are difficult to recognise in most specimens, because
they are small and undeveloped ; but nevertheless they are always
present, extending nearly the whole length of the belly cavity on
either side of the intestine. The young eggs in the females can be
recognised under the microscope even in the narrowest roes. The
female organ is band-shaped and not tubular as in most fishes ;
the eggs are borne along the outer side; there are no tubes to
conduct the eggs to the exterior, but they escape by a small open-
ing behind the vent. The eggs when ripe must therefore become
free in the belly cavity before they are shed. The male organ,

THE EEE HAMGEY: 193

on the other hand, is spongy as in other fishes, and the milt
escapes by a tube or duct.

Eggs of the buoyant transparent kind found in the Bay of
Naples have been recognised as belonging pretty certainly to
fishes of the eel family, but have not been connected with par-
ticular species. Only the conger and the fresh water eel occur
in the British Isles, and no buoyant eggs which could possibly
belong to them have yet been found off the British coasts. The
ripe eggs have never been obtained from the fish themselves.
The young forms have recently been recognised in certain
peculiar, band-shaped, transparent fish previously described as
distinct species under the name Leffocephalz. It is practically
certain that both eel and conger spawn only once and then
die, and the males are much smaller when mature than the
females.

The Leptocephalt (which means literally small-heads) have
some of the characters of the larve of other fishes, but they have
also many striking peculiarities of their own. Like other fish
larve they are transparent and have no scales or silvery layer in
the skin, and the bony skeleton is not developed.

Their chief peculiarities are the great height of the body from
the back to the belly and its remarkable thinness from side to
side, the small size of the head, and the large size of the whole
creature. The largest specimen described was 10 inches long,
but the more usual length is 5 or 6 inches, and some are smaller
than this. The vent is usually near to the hinder end of the
body. It is remarkable that the great vertical depth belongs to
the body itself, and is not due to the presence of a broad fin
membrane like that of other fish larvae. On the contrary, the
fin membrane is very narrow or absent, and in cases where a
longitudinal fin with rudimentary rays is present, this also is
narrow. In the thin specimens there is no red blood, but speci-
mens have been described in which the body was more rounded
and red blood was present ; in these the whole development was
obviously more advanced.

These curious forms have been taken on the English coasts,
in the Mediterranean, especially in the Straits of Messina, and
in the surface waters of the ocean in various parts of the world
within the tropics. They are nowhere common except in the
Straits of Messina, where they are caught by boys when bathing.

O

194 MARKETABLE BRITISH MARINE FISHES

Evidently their powers of swimming are not great. There are
differences of shape and structure among them, and a number of
species based upon these have been described. Only one kind
has been taken on English shores, and this kind, formerly called
the Morris, occurs also at Messina. In England only a few
specimens have been taken since it was first discovered in 1763.
It is usually 5 or 6 inches long and $ inch broad.

Various theories were formerly proposed concerning the nature
of the Leptocephali. In 1861 it was suggested that they were
the larve of certain fishes which had an elongated narrow band-
like form in the adult condition, namely, fishes of the same
family as the red band-fish of British waters (Cefo/a). But the
anatomical peculiarities, such as the position of the vent and
absence of pelvic fins in the Leptocephal, did not agree with
this supposition, and in 1864 an American naturalist announced
his opinion that they were the young of the eel family, and in
particular the English form Morris, the young of the conger. Dr.
Giinther in 1870 expressed his agreement with this view with
regard to the derivation of the Morris, from the conger, but was un-
able to accept the idea that the Leptocephali were the natural
ordinary condition of the young of fishes of the eel family,
because they are so large, and he had seen young conger smaller
than the known specimens of the Morris. He suggested there-
fore that the Leptocephali were monstrosities, were larvae which
having got into unnatural conditions had gone on growing in
the larval state without going through their proper transforma-
tion.

In 1886 however, at Roscoff in France, a specimen of the
Morris was kept alive in the aquarium and actually observed to
change into the conger, and in 1891 and 1892 Grassi and
Calandruccio, two Sicilian naturalists, made very careful and
successful experiments on the Leffocephalz taken at Catania,
and actually observed the transformation of different kinds of
the larve into different kinds of eel-like fishes found in the
Mediterranean, including the conger. The difficulty pointed out
by Dr. Giinther is explained by the fact that the Lepfocephali
take no food during their transformation, and become very much
reduced in size. Such a reduction in size during transformation
is known in other animals.

The habits of the Leptocephali are not fully explained. In

THE EBL FAMILY 195

the Straits of Messina they are taken in mid-water or near the
surface, and the oceanic forms have been taken at the surface.
But at Catania they were taken in fine-meshed seines which were
dragged along the bottom, and in the aquaria they hid away in
groups, making their way into the intricate crevices between and
under stones, or any other objects on the bottom or burrowing
into the sand: they also sought the darkest corners and re-
treated from the light. In England the Morris has been taken
by the prawn-net worked by hand on the shore, and also
occasionally at the surface. But neither in the Mediterranean
except at Messina, mor on the Atlantic coasts of Europe
have these creatures been taken in the fine-meshed tow-nets
so much used by naturalists in the sea. It seems evident,
therefore, that these curious creatures live naturally on the
sea bottom, but then the question immediately arises, Why
are they not taken in the dredge?—a question to which
we cannot at present give a satisfactory answer. The larve
of the eel and conger must be very abundant somewhere.
At Messina the reason that the Leptocephali come so much
under observation is probably that the strong currents of that
strait, famous for its reefs and whirlpools among the ancients,
dislodge them from their retreats at the bottom and carry them
about in the eddies. There is no doubt however about the fact that
the oceanic forms are found at the surface, as a regular feature
of the surface captures, and it seems probable that these will be
found to belong to particular species of the eel family different
from those whose larve have been studied in Sicily.

The buoyant eggs which it is practically certain belong to
fishes of the eel family were described and figured by the Italian
naturalist Raffaele at the Zoological Station of Naples. They
resemble the eggs of the pilchard more closely than any others,
but are larger. They have a compound yolk composed through-
out of separate masses, and some have a single oil globule,
others 6 to more than 30. The space between the egg proper
and its enveloping membrane is large, as in the egg of the
pilchard. The size varied from 2 to more than 3 mm. (,%; to
=; in.). That these ova beiong to this family is proved by the
fact that the larvae hatched from them have, when the yolk is
absorbed, the peculiar and elongated body of the youngest
Leptocephalt, observed by Grassi and Calandruccio. But we

OR2

196 MARKETABLE BRITISH MARINE FISHES

know that, as in the case of the pilchard and herring, some fish
of a family may have buoyant eggs while the eggs of others
develop at the bottom, and, as mentioned above, no buoyant
eggs which resemble those attributed to the eel family have yet
been observed in British waters where the eel and conger are so
abundant. Only two species are commonly found in British
waters, namely, the common eel and the conger, but a third, the
Murena, is recorded to have been twice taken on the south
coast of England. The peculiarities distinguishing the two
former are the following.

The Eel: cyes small, upper jaw shorter than the lower,
dorsal fin commencing a considerable distance behind the
pectoral ; small scales embedded in the skin.

The Conger: cyes large ; upper jaw larger than the lower ;
dorsal fin commencing close behind the pectoral ; no scales.

The Eel (Anguzlla vulgaris).

Distinguishing Characters ——Gill openings rather small, eye
small, upper jaw not longer than the lower, dorsal fin commencing
some distance behind the pectoral. Teeth small, not in rows.
The cleft of the gape extends back to the middle or hinder edge
of the eye. Small scales embedded in the skin. The colour is
dark olive along the back, white or yellow on the belly. The
females grow to over 3 feet in length.

Habitat.—The eel is found in all the fresh waters of Europe,
except the Arctic regions, the Danube, the Black Sea and the
Caspian ; it also occurs on the Atlantic side of North America.

Their food is varied, and consists of almost anything alive
that they can swallow, and also carrion.

Breeding —The male sexual organ of the eel was first
described by the Italian naturalist Syrski, at Trieste, in 1873 ;
the organ, as seen by him, was not in the ripe condition, but
differed from the female organ in being smooth outside and
formed of fleshy lobes, in the interior of which were tubes and
a main conducting tube opening to the exterior behind the
vent. The female organ is a narrow band with folds across on
the outer surface, these folds containing the eggs embedded in
fatty tissue. Since the discovery of the male organ it has been

EE

THE EEL BAMIEY 197

ascertained that the males are the variety formerly described as
the broad-nosed eel, having a broad head and snout. But a
more certain distinction is that the dorsal fin commences farther
back than in the female, the distance between the commence-
ment of the dorsal and of the ventral being less than the
length of the head. Male eels are always smaller than the
female, the largest recorded being 1 foot 74 inches long. They
remain more in the neighbourhood of the sea than the females,
being found mostly in the brackish water of river mouths, and
rarely far above the reach of the tides.

The female eels form the supposed variety called the sharp-
nosed eel, the head being narrower and the distance between
the commencements of the dorsal and ventral as great as the
length of the head or greater. These are found in all rivers
as well as in isolated ponds, which they reach by travelling over
land. Females have been recorded up to 3 feet 3 inches in
length, or even more.

The females migrate down the rivers in October and Novem-
ber, and it is at this time that some of the most productive
fisheries are carried on, large wicker-work traps being placed in
the river with their mouths directed up stream. A Danish ob-
server has recently published a paper showing that the fishermen
and dealers distinguish between yellow eels and silver eels, and
that the former are better nourished than the latter, while in
these the generative organs are more developed. He concludes
that the change in appearance accompanies the approach of the
breeding process.

Another difference in the silver eels is the considerably
greater size of the eyes, and this agrees with the enlargement
of the eyes which I have myself observed in ripe male conger.

There is no distinct evidence that eels ever return after their
migration to the sea, and although ripe specimens have never
been obtained, nor the eggs discovered, it is most probable that
the eggs are shed and develop in the sea, and that the parents
die after spawning.

It has long been observed that early in the year, from
February to May, young eels ascend rivers. Buckland has
described how they pass in great multitudes in a procession
about 18 inches wide, close to the banks of the river in the
Parrett. They are dipped out with a hand-net, salted, and

198 MARKETABLE BRITISH MARINE FISHES

made into cakes. I have found these young eels on the shore
under stones in Plymouth Sound in February and later. They
are 2 to 4 inches long, and extremely transparent, except
for a black line inside the body along the spinal cord. There is
no difficulty in understanding how fresh water streams and
ponds are abundantly supplied with eels from the multitudes of
young which ascend from the sea.

It must be well understood that these young eels, elvers or
eel fare, although very transparent and having no pigment and
probably no scales in the skin, are otherwise fully developed,
and have the fins and other characters of the adults. But
before they reach this condition they pass like other fishes
through a transformation which is not yet fully known.

In the course of their interesting researches upon the Lepéo-
cephali, Grassi and Calandruccio have convinced themselves that
one of these forms, previously known as a distinct kind, is the
larva of the common eel, as the Morris is the larva of the conger.
The form in question, named Leftocephalus brevirostris, or the
short-snouted Leftocephalus, is rather small, not exceeding 3}
inches in length, and + inch in vertical breadth. The Sicilian
naturalists have not been able to follow the entire transformation
on one and the same specimen, but in several individuals kept in
confinement they have seen the most important changes, and have
traced in a number of specimens a complete series of steps from
the Leftocephalus to the young transparent eel. The reduction
in length during the change may be more or less in different indi-
viduals, but it does not exceed #2 inch, so that the smallest
perfect eels are 2 inches long. The investigators convinced
themselves that young eels with the characters of the adult have
never been found less than 2 inches long, so that there is no
evidence to contradict their conclusions. But it is a strange
fact that the particular Leptocephalus which they connect with
the cel has never yet been found except in the channel between
Sicily and the mainland. The only conclusion to be drawn is
that the Leptocephali escape capture on account of their powers
of concealment. It remains for British naturalists to discover
these larve in British waters.

It seems at first sight probable that the elvers which ascend
rivers in spring are the offspring of the parents which descend
the previous autumn. But considering the case of the conger,

eee

THE BEL FAMILY 199

and the small development of the sexual organs in the eels
which migrate to the sea, it seems likely that some months
must elapse before the organs are fully developed and spawning
takes place. We do not know how long it takes for the larve to
develop up to the time at which the transformation commences :
the latter process in the conger takes a month or little more. It
is possible therefore that the elvers when they ascend rivers
are about six months old, and are derived from parents which
spawned the previous summer, and migrated to the sea the
autumn before that.

Eels seem to take some years to grow from the condition of
elvers to the mature condition in which they descend to the sea.
It has been stated that they take four or five years to reach a
weight of 5 or 6 lbs.

The Conger (Conger vulgaris).

Distinguishing Characters—Head and eyes larger than in
the eel. Gill openings large. Dorsal fin commencing close be-
hind the breast fins and continued into the ventral round the
end of the tail. Mouth wide, the upper jaw slightly longer than
the lower: gape reaching back to the middle of the eye. The
front nostril tubular. Teeth in a row close together, forming
a cutting edge. Colour dark above, light or white beneath.
White spots mark the openings of the lateral line. No scales.
Margins of the fins black. Light-coloured specimens are often
caught: their colour has become lighter because they have been
lying on sandy ground. The females attain sometimes to over
8 feet in length and 128 lbs. in weight, but this is rare, probably
unique. Specimens between 6 and 7 feet in length and over
60 Ibs. in weight are more frequently taken. The small specimens
are called ‘straps’ by the fishermen at Plymouth.

Habitat.—Coasts of Europe, Mediterranean to St. Helena,
also in Japan and Tasmania. It occurs in the Orkneys, and is
fairly common on the west coast of Ireland, but less common in
the North Sea than in the English Channel.

Food.—Fish and squid or cuttlefishes, also crustacea. It is
much given to cannibalism, and the females swallow the smaller
males.

200 MARKETABLE BRITISH MARINE FISHES

Breeding.—The death of large females in aquaria and the
great development of the ovaries in them has been repeatedly
observed. In large specimens captured in the sea by hook the
roes are often found to have a considerable size. I have seen
them as much as 3 inches wide with the eggs visible as separate
grains to the naked eye. In such specimens the roe is intensely
white, and fishermen often deny that it is roe or ‘pea,’ asserting
that it is merely the fat. There is much fat in the roeim this
condition, but the eggs are scattered through it and can be
recognised without much difficulty. The roes in females which
have died in aquaria are larger and the eggs also larger: the
fat is entirely absent. The weights of the roes were taken and
the number of eggs calculated in the case of females which died
in the Southport aquarium in 1876, and in the Berlin aquarium in
1881. In a specimen only 22} lbs. weight the total number of
eggs was calculated to be over six million by Mr. Jackson of
Southport, while in Berlin only three million were calculated in a
specimen weighing 224 lbs.,.of which the roes weighed 8 lbs. In
another calculation given by Buckland, in a conger 6} feet long
weighing 69 lbs., whose roes weighed 7} lbs., the number of eggs
was over 14 million. I myself calculated the number in a specimen
5 feet 4 inches long, 33 lbs. 8 oz. in weight, whose roes weighed 7 lbs.
63 0z., at nearly eight million. The death of conger in the same
condition, with their bellies distended with the enlarged roes, was
also observed at the Naples aquarium.

The male conger was discovered by Dr. Otto Hermes,
Director of the Berlin aquarium, in 1880. A number of specimens
caught near Havre were sent to that aquarium in 1879: they
were 2 feet to 2 feet 4 inches long. All grew rapidly except one
which died on June 20, 1880, and was then only 2 feet 5 inches
long. When it was opened it was found to contain large soft
roes somewhat like those of the herring, and these were full of
ripe milt.

My own experiments and observations at Plymouth extended
our knowledge of the conger considerably. I confirmed Dr.
Hermes’ description of the ripe male organs, and examined a
number of male specimens alive and dead in the years 1887 to
1890. I found that when a number of small conger, less than
2 feet 8 inches in length were obtained from the fishermen, there
were nearly always some males among them. In some of these

EE

a

ee

EE EE, RVAUManE 201

the soft roes were of considerable size and well developed, in
others» they were very small, but in no case were they
actually ripe. On the other hand ripe male specimens were re-
peatedly obtained among small conger, under the above limit of
length, kept alive in the aquarium. The largest male which I
measured was 2 feet 2 inches long, and the smallest ripe specimen
18 inches. I found it was usually possible with some care and
practice to distinguish the males from females of about the
same size. The chief differences are that the belly of the male
is more pigmented than that of the female, that the snout of the
male is blunter at the end and flatter above than that of the
female. The eyes are larger in ripe males that are kept alive
some time in the aquarium, but this is a difference that cannot
be relied upon in unripe males. In fact, as might be expected,
all the differences are less distinct in unripe specimens, so that
it is easy to be mistaken in picking out certain specimens as
males. I was able however to select a number of living males
and keep them alive until they became ripe, and found that this
could be done without any difficulty. Ripe male conger can
thus be obtained in a well-appointed aquarium in any numbers
desired. I further observed that ripe males do not feed, and
that although they continue to live for a long time they become
gradually thin and weak. The emaciation of the head causes
the eyes to have a proportionally large size and strikingly pro-
minent appearance, which is alone sufficient to distinguish a ripe
male to an experienced observer. It need scarcely be said that
the ripeness of the males was ascertained by taking them out
of the tank and gently squeezing the belly ; the ripe milt escaped
freely, and was examined under the microscope, so that its
nature was ascertained beyond a doubt. One of these ripe
specimens lived from December 13th to the following June 24th,
when it died. Throughout this time it took no food, and it
gradually became very weak, thin, and maimed. On March7th
it still yielded milt, which was quite healthy, and the fish when
touched moved with considerable activity. But it was quite
blind, one eye being entirely ulcerated, the other clouded and
opaque. The skin was torn or rubbed off in places. When it
died its condition was still worse.

The males seemed to be less numerous than the females even
among specimens of the same size: of thirty-four recorded

202 MARKETABLE BRITISH MARINE FISHES

eleven were males and the rest females, and considering that all
specimens over 2 feet 8 inches are females, the numerical
superiority of that sex must be very great.

To turn now to the consideration of the females, I made
careful observations on some large specimens which lived in
the tanks. One of these was noticed in December, 1888, to
be somewhat swollen, as though the roes were enlarged, and
in March, 1889, she ceased to take food. I several times
squeezed this fish, an operation of considerable difficulty effected
by placing her head in a sack, and got a few eggs from her
which measured nearly ,'; inch in diameter: but these eggs were
white and opaque and evidently not ripe. This female died on
September 1oth, having lived without food since the previous
March, or about six months. In January 1890, I removed two
other females which had ceased to feed, and placed them in a
tank with eight males, some of which were quite ripe, and
yielded milt on squeezing. It will be seen that the fact that
the female ceases to feed while the eggs in the roes are ripening,
and doubtless when they are ripe, enables the males to approach
her and secure the fertilisation of the eggs: the male which
approaches a hungry growing female is pretty certain to be de-
voured. In the specimens separated for observation it was seen
that the females frequently pressed their abdomen against the
gravel at the bottom, and especially the region of the vent. The
males took considerable notice of the females ; one of them rested
for days constantly by the side of one of the latter, returning
with great pertinacity when driven away. But no spawning took
place, one of the females died on March 24th, the other on
April 22nd. The day before death they writhed and twisted
about on the bottom as though trying to get rid of their
egos. But the eggs examined’ after the death of the fish
were not ripe, they were in the same condition as in the female
previously mentioned. They were ;'; inch in diameter, and still
contained in the substance of the roe.

In these females the intestine and stomach were not only
empty but much reduced in size, and all the organs including
liver and spleen were squeezed into the smallest possible space
. by the great enlargement of the roes. In one specimen 4 feet
5 inches long the roes weighed 3 lbs. 44 oz, the other organs 8 oz.
In the other, 5 feet 11 inches long, the roes weighed 4 lbs. 5 oz.

THE EEL FAMILY 203

It is very likely that the reason why female congers do not
spawn in aquaria is that the depth of water is not great enough.
I tried the experiment of putting down two females in a box
in the sea, but one female died in the usual condition, and the
box was lost with the other.

With regard to the condition of the eggs in females which
die in the way described, their size has already been mentioned.
The yolk is composed of minute globules, and there is no
appearance of distinct oil globules. When placed in sea water
they sank to the bottom, and after some time a separation
took place between the membrane and the yolk. This indicates
how near they are to ripeness, but there is nothing to show
whether the eggs are of the buoyant kind or not.

There are two questions of considerable interest arising out of
these facts: first, how far is the behaviour of the fish natural
and how far due to the confinement ; secondly, what probability
is there of obtaining ripe eggs from conger? My own conclusion
concerning the first is that the behaviour of the conger is in all
respects natural except that death is somewhat premature.
There can be no reasonable doubt that the conger in the sea
ceases to feed about six months or more before spawning, and
that during that time, as in the aquarium, the roes are develop-
ing at the expense of the fat and substance of the rest of the
body. In the sea, however, we must suppose that the fish lives
- until it has spawned. That it then dies is, I think, certain. In
the specimens studied in the aquarium, both males and females,
it was found that after death the skeleton was in a remarkably
degenerate condition. The bones of the head had lost all their
hardness, in consequence of the absorption of the lime from them.
They were softer than gristle, and could be cut with a knife
nkcemvcheese, Ihe teeth had all dropped® out except a” few
which were loose. The flesh was much reduced and the skin
often torn, but this happened more in the males than in the
females. That a fish which had sunk to such a condition as this
could recover its former vigour is impossible to believe. In the
sea without teeth and without muscular strength it could not
capture prey, and without food it could not recuperate itself.
The conclusion is that the conger spawns only once and then
dies, and that in the aquarium the female dies a little too soon.
The reason for this premature death in the aquarium is probably

204 MARKETABLE BRITISH MARINE FISHES

the shallowness of the water, the fish being adapted to spawn
under a pressure of twenty or thirty fathoms. In the same way
the soles in the aquarium for some years did not spawn, but
expelled their eggs in the dead condition.

There seems no probability of obtaining ripe female conger.
In the sea they cannot be caught on hooks because they do not
seek food, and they do not come in the way of the trawl because
they remain among rocks. The only methods by which they
might be obtained are that of keeping them in a cage at the
bottom of the sea, and keeping them in an aquarium tank in
which the pressure was artificially increased ; both methods
involving considerable expense and trouble.

The Leptocephalus Morrisii or Morris, which is the larva of
the conger, has been described by the older naturalists, but the
descriptions and figures are not perfectly satisfactory according

Fic. 99.—Leptocephalus Morrisiz, the larva of the Conger ; after Couch.

to modern requirements. Fig. 99 is an outline copy of the
figure given in Couch’s work.

The length of the first specimen described was 4 inches, of
others 54 and 6 inches. Grassi and Calandruccio state that
larve 5 inches long, are reduced, after the transformation, to
congers of 3 inches. The transformation may not take more
than a month; it was observed in 150 individuals, and the
creatures were kept alive without difficulty in aquaria or even
in tubs. The Leftocephali, according to Couch, the Cornish
naturalist, are not unfrequently obtained entangled among sea-
weed. I never had the good fortune to find any either at
Plymouth or elsewhere. But a perfect specimen was obtained at
the Plymouth Laboratory in 1894. It was found by a boy on
the shore of the Sound. Two were taken in the Irish Survey,
in a tow net attached to the trawl beam.

I have found that conger less than 15 inches long are usually
not black or dark like the adults, but pale and pinkish in colour
on account of the small amount of pigment in the skin. The

Es

THE EEL BAMILY 20

ut

smallest in my collection was 82 inches long, and was taken
in the beam trawl.

Mr. Jackson, of the Southport Aquarium, found that of a lot
of congers taken when only 2 or 3 lbs. weight, one died after
about two years weighing 21 lbs. and with greatly enlarged
roes, another after four years when it weighed 69 lbs., another
after five and a half years when it weighed 90 lbs. The age
and size therefore at which the development of the roes takes
place are very different in different individuals.

THE GARFISH OR GUARD-FISH FaMiry:

THIS family includes the guard-fish, the skipper or saury pike
and the flying fishes. In these fishes there is a single dorsal fin
far back, opposite the ventral: behind these there are in the
skipper or saury pike a row of five or six finlets as in the mack-
erel. The pelvic fins are placed far back, as in herring, salmon,
&c., but the air-bladder has no connection with the gut. In
both garfish and saury pike the jaws are prolonged into a narrow
slender beak, longer in the former than in the latter. The teeth
are larger in the garfish. It is a peculiarity of the garfish that
its bones are green, retaining this colour when cooked. In the
flying fishes (species of Aaocetus) the jaws are short, but the
pectoral or breast fins are very much elongated and enable the
fish to sustain short flights in the air. The flying fishes belong
to the tropics and the open ocean, but one or two specimens
have been obtained on the south coast of England.

The garfish regularly visits the British coast, as well as Ire-
land and the Orkneys and Shetland in summer, migrating to
the more distant sea in winter. It is found from Iceland and
Scandinavia to the Mediterranean.

Along the south coast the fish spawns in May and June,
and is then often taken in mackerel nets. It has long been
known that its eggs are provided with long threads or processes
at two opposite points, and these threads are adhesive. But the
eggs have never been found after being shed in the natural
condition, and it seems uncertain whether they develop at the
bottom or float about in bunches formed of a number of eggs
sticking together by the threads. Day states that. he received
from Mr. Dunn a portion of a mackerel net with many eggs of
. the garfish attached to it, eggs which had been shed by fish
caught in the net. But it may be that the fish deposits its eggs

THE GARFISH OR GUARD-FISH FAMILY 207

naturally in the open water near the surface, and that they stick
only to one another without becoming attached to the bottom.
On the other hand, the American naturalist Ryder states that
the eggs of a kind of garfish sink in sea water. He has observed
that the eggs of one female form a cluster by the mutual adhe-
sion and entanglement of their threads.

I have found young garfish among the produce of the ground
seine in the Hamoaze in September. They were fully developed,
being 4 to 5 inches long and over a year old. The younger
stages have been shown to undergo a curious transformation.
Thus Couch describes a specimen } inch long in which the jaws
are scarcely elongated at all, only the lower jaw is commencing
to grow out and is longer than the upper. At a little over
34 inches the lower jaw is proportionally almost as long as in
the adult, but the upper jaw is still quite short. The various
intermediate stages have been captured at the surface and de-
scribed, and the connection between these young fish and the
garfish fully proved, although when the young fish with the
upper jaw undeveloped were first obtained they were described
as a distinct kind of fish. In tropical regions there are numer-
ous kinds belonging to this family in which the jaws remain
always in the condition which is only temporary in the young of
the gar-pike. These are called half-beaks, and some of them
live in fresh water and bring forth their young alive.

The saury pike occurs annually on the Cornish coast, and
along the south and east coast of Britain is taken but not in
abundance. Its eggs have filaments for attachment like those
of the gar-pike, but its spawning on British shores has not yet
been described.

THE PEATEs EL Avice

THE three chief peculiarities of the flat-fishes are (1)
that the two eyes are on one side of the body, (2) that
the upper or eyed side is coloured, the lower side white, (3)
that the dorsal fin extends forwards as far as or beyond the
eyes, but along the edge of the head, not between the eyes. It
is not difficult, ifa flat-fish such as a plaice and an ordinary fish
such as a haddock are examined together, to see what the real
differences are, though probably few who handle flat-fishes daily
in the course of business ever trouble to make the comparison.
Fishermen, however, are accustomed to distinguish between left-
handed and right-handed flat-fishes, and in doing this they place
the edge on which the mouth and belly are, towards themselves, as
one naturally does in looking at one of these fishes. On this
edge also are the gills, while on the other is the brain. It is
easily seen that apart from the eyes and colour the upper side and
lower side are very much alike, and are really left side and right
side. There is a gill-flap on each side, and a breast-fin and a throat-
fin. It follows therefore that the two fins which run along the
edges of the body are the dorsal or back fin, and the ventral or
belly fin, corresponding to those of the ling or tusk. In a tur-
bot or halibut it will be seen that the two sides of the mouth are
almost exactly alike in size and shape, so that the peculiarity of
the eyes of a flat-fish does not necessarily make the mouth lop-
sided. In fact the position of the eyes is due entirely tora
twisting of the part of the face containing the eyes, toa bending
round of the bridge of the nose, which brings the right eye on to
the left side or the left one to the right side as the case may be.
The front part of the dorsal fin is on the side of the face, there-
fore, separating the eye nearest to it from its proper side of the
head. In certain flat-fishes, especially the turbot, specimens are

THE FLAT-FISH FAMILY 209

occasionally taken in which the dorsal fin does not extend for-
ward in the usual manner, but forms a hook overhanging the
eye nearest it, and in these specimens it is easier to see how the
face is twisted.

There are no large spines in the flat-fishes in the fins or on
the bones of the head, but a small one projects in some in front
of the ventral fin. The scales are variously developed ; in some
they are present all over the body and have a spiny margin as
in the common dab, in others they are rudimentary as in the
plaice, in others they are developed into rough tubercles as in
the flounder and turbot. It should be noted that in these fishes
the great extension of the ventral fin causes the vent to have a
position very near the head ; it is further forward than even in
the whiting and other fishes of the cod family. The opening of
the roes is just behind the vent, also in front of the ventral fin,
but the belly cavity being very small the greater part of the roe
on each side is situated behind it, between the flesh and the par-
tition of bony spines in the middle of the body.

The following are the British species with their distinctions :—

I. Species with the eyes on the right side, the mouth at the
end of the snout, teeth most developed on the blind side.

I. The Plaice.—Scales small and embedded in the skin;
bony knobs on the head behind the eyes, red spots on the
upper side.

. The Flounder.— Rough tubercles along the bases of the

marginal fins, and along the lateral line.

. The Dab.—Scales all alike, with toothed edges, making

the skin rough.

4. The Witch.—Shape oblong, scales all alike, very slightly
toothed on upper side: blister-like cavities beneath the
skin of the head on the lower side.

5. The Lemon Dab.—Scales small and smooth, skin very
slimy, head and mouth very small, colour yellowish brown
mottled with large round marks.

i)

ios)

II. Species with eyes on the right side, mouth large and jaws
similar on the two sides.
6. The Halibut.—Scales smooth, lateral line with a curve,

size very large.

iP

210

MARKETABLE BRITISH MARINE FISHES

7, The Long Rough Dab.—Scales rough, lateral line

Te

straight, size very small.

Species in which the eyes are on the right side, the snout

projects beyond the jaws, the front margin of the head curved,
jaws larger on the lower side, and teeth only on that side: a
“beard” of short projections from the skin on the lower side of
the head.

8. The Common Sole.— Breast-fins rather large on both sides,

nostrils alike on the two sides : colour, rows of black
blotches on brown ground.

9. The French Sole or Sand Sole (or Lemon Sole).—Nostril

10.

1

IV.

on lower side enlarged : specks instead of black blotches.
The Thickback.—Breast-fins very small: colour five
dark bands across the body on a red ground.
The Solenette.—Breast-fins very small: black blotches
as in the common sole, but in addition a line of black on
every fifth or sixth ray in the dorsal and ventral fins.

Species in which the eyes are on the left side, the mouth

is large, at the end of the snout, and teeth and jaws are equal on
both sides.

Wa

13:

14.

Tee

16.

17,

The Turbot.—Diamond-shaped body of large size, no
scales but blunt bony tubercles.

The Brill.— Body more oval, covered with smooth scales.
The Megrim.— Body narrow and thin, scales rough ; eyes
very large, and mouth also: colour light yellow.

The Scald-fish or Scald-back.—Eyes and mouth
smaller, scales rather large, but the skin is very thin and
tears off during capture: the first rays of the dorsal fin
much elongated in the adult male, not in the female.
The Common Topknot.—Scales very rough, marginal
fins continued beneath the root of the tail, throat fins
united with the ventral.

The One-spotted Topknot.— Like the last, but having
the first dorsal fin-ray prolonged, and asingle round spot
on the upper side towards the tail : under side very rough.

The Norwegian Topknot.—A smaller fish having
neither the throat fins united with the ventral fin, nor the
first dorsal ray prolonged.

AMISHS, INGA SIMES Sl AVN os 2a

Of these eighteen kinds all are used as food except five,
_namely, the solenette, the scald-fish, and the three topknots.

All the flat-fishes possess in a remarkable degree the power
which is present in all fishes, of changing their colour, or the
intensity of their colour, in accordance with the tone of their
surroundings. On a light sandy ground they become pale, on a
dark muddy ground they become almost black. Their habits
have been sufficiently described in a previous part of this book.

The eggs of all the British flat-fishes are of the buoyant and
separate kind, but it has recently been discovered that those of
an American species, the winter flounder (Pseudopleuronectes
Americanus), are heavy and adhesive, and are best treated in
the hatchery by being spread on panes of glass. This fish
resembles the plaice and dab, having rough scales like the latter.
In Europe even the flounder, which lives chiefly in brackish or
nearly fresh water, produces floating eggs, and goes down to the
sea to spawn. It is a curious fact that the eggs of most of the
right-sided species, plaice, dab, flounder, lemon dab, witch,
halibut, and long rough dab, are without an oil globule, while
those of all the left-sided species, from turbot to Norwegian
topknot, have a single oil globule. The eggs of the soles have a
number of small oil globules.

The common character of the newly hatched larve is that
the intestine ends immediately behind the yolk, and opens on
the edge of the fin-membrane. In other respects the larve of
the flat-fishes are very much like those of equal-sided fishes, and
at first they swim near the surface and feed on the minute float-
ing creatures in the same way.

Mention has already been made, in the first part of this book,
of the fact that the peculiarities in the position of the eyes and
in the habits of flat-fishes are acquired when they are still very
small, during the transformation of the larva to the adult condi-
tion. The mode in which the extraordinary position of the eyes
was brought about gave rise, when the transformation of the
larve was first discovered, to a lively controversy.

A good many years ago the Swedish naturalist Malm, whom
I have previously mentioned, noticed small turbot, plaice, and
other flat-fishes in which the eyes were not both on one side
of the head, but in various positions which seemed to show that
one eye was gradually moving round to the other side, passing

Pe 2

PMA MARKETABLE BRITISH MARINE FISHES

over the edge of the head. These fishes were very small, less
than an inch long, and Malm concluded that this was the way
in which the curious position of the eyes was reached. He was
able to prove that in the flounder when it began to develop in

Fig. 100

4, =
“ately
vt Mf,

Wi. al
w e

Fics. 100-105.—The two sides of the head in three different stages in a left-sided
young flat-fish in which the right eye passes through the head region to reach the
left side (Rhombotdichthys). The two upper figures show an eye on each side of
the head, but the right eye is higher in position. In the middle figures the right
eye is beginning to appear on the left side through a slit above the left eye. In
the third figures the passage of the right eye is very nearly completed. (After
Steenstrup. )

the egg there was an eye on each side of the head. About the
same time, in the years between 1860 and 1870, a naturalist in
Denmark obtained some small specimens of flat-fishes in which
the eye of the lower side was in various stages of migration
through the head, sinking in on one side and coming out again

THE PLAT-FISH FAMILY 213

on the other. Figs. 100-105 are copies of the figures which this
naturalist published to illustrate the condition of these speci-
mens. He did not find that these flat-fishes were the young of
our common kinds, but that, on the contrary, they belonged to
a kind which is not taken on our coasts. These two naturalists
accordingly had a dispute as to the way in which the eye of the
lower side in a flat-fish gets to the other side, one maintaining
that the eye went through the head, the other that it went
round. The truth was that both were perfectly right, each gave
a correct account of what he saw, and formed a true judgment
upon it, and neither had any reason to throw doubt upon the
statement of the other. The specimens in which the eye was
seen on its way through the head were caught in the open
Atlantic Ocean by ship-captains. Inthe year 1878 a naturalist
in America actually kept alive specimens of young flat-fishes in
some of which the eye went round the head, and in others
went through. He watched the little fish while the change
was taking place. The facts are now thoroughly well established,
and the change in position of the eye in the common flounder
and in other kinds can be watched every spring in specimens
caught at low tide at favourable places on the coast. In the
kind of flat-fish in which the eye goes through the head it
is known now that there is very little real difference in the
process from that which is more common. In this kind the fin
on the edge of the body extends forwards to the snout while the
eyes are still opposite to one another, and the eye of the lower
side simply tunnels under the fleshy part of this fin, and never
actually passes through the bones of the head. In the sole and
turbot the fin does not grow forwards to the end of the snout
until after the shifting of the eyes has taken place.

The Plaice (Pleuronectes platessa).

Distinguishing Characters—The rough bony knobs on the
head are on a bony ridge extending from the ridge between the
eyes to the upper corner of the gill opening. The number of
fin-rays is not different from the number in the dab: there are
sixty-six to seventy-seven in the dorsal, fifty to fifty-seven in the
ventral, but the smooth minute scales and the straight lateral

214 MARKETABLE BRITISH MARINE FISHES

line are characteristic. The teeth of the plaice are peculiar,
being broad and flat, and ending in straight edges: there are
also rounded crushing tecth in the throat. Colour, a number of
orange or red spots on a brown ground.

Szze.-—The largest measured by Dr. Fulton on the east coast
of Scotland was 28 inches long. At Plymouth they do not
usually exceed 20 inches: the usual size is 15 to 18 inches, the
largest 24 inches. The largest measured by Holt on the west
coast of Ireland was 26 inches. Farther north they are larger.
Mr. Holt found from observations on the Grimsby pontoon
that the smallest plaice brought by trawlers from Iceland was
12 inches long, few were less than 17 inches, a great many were
27 inches and specimens of 30 inches or even several inches.
longer than this were not uncommon. These fish were taken at
depths from 7 to 40 fathoms. The colour of these fish as a rule
was not so bright as that of North Sea fish, the ground colour
being a dark brown, and the spots dull rust-coloured and few
in number. On the other hand plaice in the Baltic are limited
to a considerably smaller size than those in the North Sea. In
a consignment of these fish examined at Grimsby the ripe
females were only from 9} to 134 inches in total length.

Flabitat—Extends from the Bay of Biscay to the north coast
of Europe. Is very scarce in the Mediterranean: and absent
from the east coast of the United States. It is abundant on
the coast of Iceland, and all round the British and Irish coasts.

Food.—The plaice feeds chiefly on bivalve shell-fish, whose
shells it is able to crush by means of the strong blunt teeth in its.
throat, but it also eats sea-worms. Inthe Firth of Forth, accord-
ing to the observations of Mr. Ramsay Smith in the Reports of
the Scottish Fishery Board, the bivalve most commonly present
in the stomachs was a small species called Scrodzcularza, and
next to this in frequency was the razor-shell (So/ez) ; cockles,
and scallops or clams (Pectez) were also present. Of the worms
all kinds are devoured, sea-mouse, lug-worms, rag-worms, and
tube-worms. Crustaceans in the Firth of Forth were not often
among the food, being represented only by an occasional shrimp
or crab. Sand-stars were more frequently eaten, fish very rarely.

In opening the stomachs of plaice from the Dogger Bank
and the Sylt grounds in the North Sea I have often found them
distended with white fleshy masses without any shells. Usually

THE BEAT-FISH FAMILY PAs

the stomach and intestines of the plaice contain crushed shells
which it swallows with the shell-fish they belong to. But in
these cases the absence of shells was noticeable. After careful
scrutiny I satisfied myself that the fleshy lumps were the so-
called “feet” of the razor-shell So/en, and it is evident that the
plaice is able to seize the “foot” of this mollusc and bite it off.
In other cases whole crushed So/exs were present, but these were
usually smaller specimens.

Time and Place of Spawning.—In the North Sea, and in the
Channel, the plaice spawns at the beginning of the year—in
January, February, and March. At Rothesay, on the Firth of
Clyde, according to Mr. George Brook, it spawns in April and
May. Off the Isle of May, Firth of Forth, eggs were fertilised
by the author on February 3rd. Mr. Holt considers it possible
that in the North Sea some plaice are still spawning in April or
even in May. At Plymouth none but spent females have been
seen after March. On the west coast of Ireland ripe females
were taken during the Survey in March and April, but none
later until August, and the record of these occurrences in August
is probably due to some mistake.

The spawning of each single female occupies a certain time,
exactly how long has not been ascertained. It is known that
full fish, those which have only just begun to spawn, yield only
a few ripe eggs when squeezed, while those which have already
shed a good deal of their spawn give up very nearly the whole
of the remainder of the crop, and so supply a very large number
of eggs. This shows that the rate of spawning becomes faster
towards the end. At first a few eggs ripen and are discharged
from time to time, but towards the end a much larger number
are discharged in a short time. From observation of ripe speci-
mens in the Plymouth Aquarium it is known that a single fish
will take several days, from a week to a fortnight or even longer,
to get rid of all her eggs.

With regard to the distribution of spawning fish, the places
at which they are found, it is known that they are not taken in
estuaries or shallow waters near shore, where the younger and
smaller fish abound in summer. They are taken in all the
deeper waters on shelly or partly shelly ground. The evidence
we have, not so abundant as could be wished, indicates that
large mature fish .visit somewhat shallower waters when not

216 MARKETABLE BRITISH MARINE FISHES

spawning, but remain on rather deeper grounds during the
spawning season. We have seen that plaice are not known to
occur at all at depths greater than 50 fathoms. The spawning
grounds may from our present knowledge be taken to be from
10 to 40 fathoms. The distance from shore varies with the
locality. Dr. Fulton found that on the east coast of Scotland
plaice do not spawn in territorial waters, that is within the three
mile limit, and this is generally true for the south and west coasts
of England, andthe Irish Sea. But onthe west coast of Ireland,
where the declivity of the sea-bottom is so much steeper,
spawning plaice were found in inshore waters, for instance in
Blacksod Bay and the Kenmare River. Smith Bank, 18 to 20
fathoms in depth, 10 to 15 miles off the Caithness shore, has been
found in the inquiries of the Scottish Fishery Board to be
specially distinguished by the number of plaice spawning there
in spring. It is also a good plaice ground at any time, because
there are beds of horse mussels upon it, on the smaller specimens
of which the fish feed. On the south coast ripe plaice are found
on all the usual trawling grounds, along the Cornish coast inside
and outside the Eddystone and in the neighbourhood of the
Wolf Rock off Mount’s Bay.

The eggs, or spawn.—The eggs of the plaice are among the
largest floating eggs of fishes known: they are a little less than
jzth inch in diameter. Actual measurements by different
observers have ranged from 1°65 to 1°95 mm. They ean be
recognised without difficulty from other similar eggs among a
number taken from the sea by means of this large size. The
egg is round, the yolk is undivided and without oil globule.

Plaice eggs naturally develop in the sea when the temperature
of the water is low, and the development is therefore slow, and
it is also slower than that of the eggs of other species even at the
same temperature. At the temperature of 53° F. in the Plymouth
establishment the eggs hatched in 10 to 12 days. Ata lower
temperature at Granton in 1886 the development took more
than 27 days. The larva when newly hatched is like that of the
flounder and dab, but much larger. It is about 3th inch in
length. The mouth is not open, the end of the intestine runs
down immediately behind the yolk. There are black and yellow
specks of pigment on the sides of the body and head, but none
on the yolk-sac, nor on the larval median fin.

THE FLAT-PISH FAMILY PANG

At Plymouth at a temperature of about 53° the yolk had
entirely disappeared, and the mouth was fully developed when
the larva was 5—7 days old. Fig. 33 shows the appearance of a
living larva in which the yolk is not yet all absorbed.

Abundant and easily obtained as the plaice is in the later
stages of its life, and easy as it is to hatch the eggs, the trans-
formation of the larva has not yet been traced out so completely
and so certainly as might be desired. Such larve have not yet
been reared in the aquarium, and in nature the intermediate
stages have not come into the hands of naturalists so frequently
as those of some other flat fishes. It has been mentioned that
at Plymouth the larve were kept alive for 37 days, being fed on
finely minced worm, and the produce of the tow-nets. But at this

Fic. 106.—Larva of Plaice five days old, alive, and magnified.

age the development of the skeleton had scarcely commenced. In
the natural condition there is at present some uncertainty in dis-
tinguishing the transformation stages of the plaice from those of
the dab, and perhaps other species. The most easily applied
test in such cases, as soon as the fin-rays have appeared, is the
number of these fin-rays, and in the plaice and dab the number
is the same, while the number in the long rough dab, though
generally greater, varies so as to overlap the variations in the
other two. The plaice has not yet been found in tide pools or at
the margin of the sea; until its transformation is complete, its
earlier stages have to be distinguished among specimens procured
with the tow-net either in mid-water or at the bottom. Fig. 107
represents the magnified appearance in the living condition of a
specimen taken near the Mewstone, outside Plymouth Sound, in
April 1891. The length was 2 inch, and the specimen was

o

identified as a plaice by its large size.

218 MARKETABLE BRITISH MARINE FISHES

In the Irish Survey a number of the earlier transformation
stages of flat-fishes were taken in tow-nets attached to the trawl-
beam in Donegal Bay, at 30 to 32 fathoms, on the 14th and 18th
of May. Mr. Holt! attributes these to the long rough dab, but
distinguishes two series—one of longer specimens, one of shorter.
From the excellent figures which he has published I have no
doubt myself that the longer specimens were young plaice, and
the smaller were dabs. There is a very close resemblance
between the figures given by Mr. Holt, and that which is
reproduced in Fig. 107.

Later stages, from that shown in Fig. 107 to the fully de-
veloped little plaice, were also taken during the Irish Survey, at

a
ut

——

Ne

4 ra
@\

Ki AN

ATH)

| war Ins
NH} HI) III)

———

i

Fic. 107.—Larva of Plaice in process of transformation, 2 inch long, alive,
and magnified.

BES

depths of 1 to 32 fathoms, in May 1892. They ranged in size from
LOO 42 Imam. (2 inch to nearly 1 inch). The oldest, completely
developed specimen could be recognised by its resemblance to the
full-grown fish in shape and appearance, and the younger forms
were separated from those of the dab by forming them into
series leading up to the oldest.

It follows from these observations that the young plaice or
larve after they are hatched sink towards the bottom during
their transformation, and that as they reach the perfect condition
they make their way towards shallower water and the shore.

In tracing out or discussing the history and growth of plaice
after their transformation from the larval condition it is very

1 Sctentific Transactions of Royal Dublin Society, ser. ii., vol. v., Memoir II.

THE FLAT-FISH FAMILY ZAG

necessary to consider different districts separately, on account
of the great differences in the size at which maturity is attained,
and consequently in the rate of growth. At Plymouth the smallest
mature females are g inches long, the largest immature less than
15 inches. The limits in length of the mature and immature
overlap one another in this way in consequence of the fact that
all individuals do not grow at the same rate or become mature
at the same age. The corresponding limits observed at Grimsby
were 13 inches and 18 inches, so that there is a difference of about
4 inches between the sizes of plaice when they first become mature
in the Channel and in the North Sea. The limits for the males
are lower in both districts, but it is doubtful if the observations
made were sufficient to determine these limits accurately: they
were 9 inches and 13 inches at Plymouth, 9g inches and 16 inches
at Grimsby. The difficulty of distinguishing immature from
spent males is greater than in the case of females.

It has been proved that the Grimsby limits hold good for
plaice throughout the area extending from the English coast to
the coast of Germany in an east to west direction, and from the
north of Scotland to the Texel in a north to south direction.
But along the Dutch coast as far north as the Texel the small
Channel plaice extend, the limits of maturity and immaturity
being the same in this region as on the fishing grounds off
Plymouth.

I have made one experiment, not a very extensive one, on
the growth of plaice in the Aquarium at Plymouth. In July,
1893, seven specimens whose lengths varied from 24 to 3% inches
were put into a tank. They were captured at sea, and believed
with good reason to belong to the brood of the year, that is, to
have been hatched in the preceding spawning season between
January and March. In the following October these specimens
measured 23 to 5% inches. In April, 1894, when they were one
year old, one of them measured 63 inches. In December, 1894,
when they were nearly two years old, the only two surviving
were 71 inches and 81 inches in length. These fish were kept
in a tank only 5 feet in length and 14 feet deep, and the number
of them was too small to afford evidence of the average rate of
erowth. But a direct observation of this kind is of great use as
a guide in drawing conclusions from the sizes of specimens taken
from the sea.

220 MARKETABLE BRITISH MARINE FISHES

At Plymouth I have not found the young plaice of the year’s
brood in any great abundance, but have taken some in Whitsand
Bay in June. The largest number obtained there in one day
by the shrimp trawl was thirty-nine, the depth at which they
were caught being 5 to 7 fathoms, and their lengths from 14 to
21h inches. Ten specimens obtained by a small seine from the
Cattewater in May measured from 4} to 7 inches in length, and
these must be considered as representing the year-old fish.
Satisfactory evidence concerning the two-year-old fish is not
at present available, but as a very small proportion of females
are mature at 9 inches, and a large proportion immature, while
three-year-old fish are mostly mature, we may conclude that the
female plaice in the Channel at two years of age are about
9 inches and at three years about 13 inches long.

More extensive observations on the sizes and growth of plaice
have been made in the North Sea. The great majority of the
small plaice taken by the hand-net shrimpers at Cleethorpes on
the shore of the Humber estuary at the end of April were found
to be from 14 to 2} inches long. These must be derived from
the spawning period immediately preceding. ‘The experiments
on the rate of growth of flounders and plaice, which were made
in the Plymouth tanks, are sufficient to show that even Channel
plaice must be much more than 2 inches long on the average
when a year old, and the North Sea plaice being larger must
grow more quickly. We know that multitudes of newly trans-
formed young flounders are found in Mevagissey Harbour, in
Cornwall, in April. These are $ inch long, and after their trans-
formation grow rapidly. The plaice begins to spawn some weeks
before the flounder in the North Sea, and we know that millions
of plaice eggs are hatched there in January. Weare forced to the
conclusion therefore that the multitudes of small plaice found at
the mouth of the Humber at the end of April, whose average
length is 2 inches, are between three and four months old. With
them are taken a few larger plaice from 3 to 9 inches long, which
of course belong to the brood of the preceding year. The small
plaice are equally abundant in May and June, the swarms of
little fish appearing on the shore in succession as they are de-
veloped from the eggs shed in February and March. In later
months plaice of this size get scarcer because they grow larger,
but some specimens less than 3 inches in length were obtained

TE Sie A TSE AMT

i)
i)
=

in September, and even in January seven specimens of this size
were taken in stake-nets near Cleethorpes. These must have
been hatched many months before, and serve to show that the
growth of a few individuals produced late in the season may be
very much retarded. Such observations prove that the remark-
able difference in growth among flounders of the same age
observed in the experiments made at Plymouth occurs also
among plaice in the sea, and it is probably due to the same
cause in the two cases, namely competition for food.

A sample of larger plaice taken in the Humber at a depth
of one to two fathoms at the end of March varied from 3} to
11 inches in length, but the greatest number were between 7
and 9g inches. A sample consisting of 425 fish taken by a
shrimp trawler at the mouth of the same estuary in May was
examined, each fish being measured. The greatest number,
namely 265, were from 7 to 8 inches long, those at smaller sizes
being fewer. These must be considered as the year-old fish,
that is to say, as far as our present evidence goes, we may
consider that the length of the largest number of year-old
plaice in spring is 7 or 8 inches. By the reasoning previously
employed we may infer that the mid-size of the two-year-old
plaice in the North Sea is about 13 inches, and of the three-
year-old about 17 inches, at the latter size all but a small
proportion being mature. These latter estimates apply only
to females, the males being smaller.

It is a notorious feature of the North Sea trawl fishery that
in the spring and summer months very large numbers of small
plaice are taken on what are known in the Humber ports as
the “eastern grounds,” these small fish being landed at Hull,
Grimsby and London. These grounds extend along the con-
tinental coast fromethe Texel to the -Horn Reef, and even
further northward towards Hantsholm on the coast of Denmark,
and from a depth of about five fathoms or even less to fifteen
fathoms or a little more. These grounds have a very slight
declivity and are for the most part level and sandy. Very few
of the small plaice taken on them exceed 15 inches in length
and the majority are from 7 to 13 inches. A small proportion
of the plaice taken in the trawl are less than 7 inches long, some
being as small as 5 inches, though those of this size are not
usually taken to market. These remarks apply to the earlier

222 MARKETABLE BRITISH MARINE FISHES

part of the season, from the end of March to the end of June,
and samples obtained from the same grounds in November and
December contained no fish under 9g inches in length. A box of
the small plaice from these grounds and bought for 3s. 9@. on
June Ist, 1895, in Grimsby Market, contained 360 fish, 211
males, and 149 females. The males were 72 inches to 11} inches
in length, the females from 7% to 13 inches. From examination
of these fish in spring and summer they were found to be with
few exceptions immature, and this result’ has been recently
confirmed by examination of large samples taken by German
trawlers in winter; all the females, with one exception,
under 13 inches were immature, and all the males under
Il inches. It is clear, therefore, that these small fish are not
small because they belong to a smaller race, like that in the
Channel and in the Baltic Sea, but because they are young and
immature. They belong to the same race, and they mature at
the same size, as the plaice of the Dogger Bank or the York-
shire coast. They consist therefore of fish in their second and
third years. The remarkable fact about them is their extra-
ordinary abundance, for they are far more abundant than are
plaice of similar size at the mouth of the Humber. As far as
our present knowledge allows us to judge, the reason for this is
the abundance of food on these grounds and the direction of the
currents in the North Sea. It has been proved that floating
objects are carried southwards and eastwards along the north-
east coast of England as far as the coast of Norfolk, and thence
in a curved direction to the German Bight, while there appears
to be a northerly drift from the Straits of Dover along
the Dutch coast. Hence it appears that of the plaice spawn
shed in the northern part of the North Sea a greater quantity
is carried to the continental shores that to the English. The
young plaice brood of the year appears to be reared in enormous
numbers on the German and Danish shores, and in spring, the
year-old fish seem to move out in a great body from inshore
grounds towards deeper water, where they join the two-year-old
fish already there, and so constitute the abundance of “small
plaice” which have attracted so much attention from those
engaged in the trawling industry in the North Sea.

EERE Ee ACRES Eie BEANIE Ve

i)
iS)

Oo

The Common Dab (Pleuronectes limanda),

Distinguishing Characters —To be recognised by the rounded
curve of the lateral line above the pectoral fin, and the roughness
_ of the skin due to the spiny scales. The ridge behind the eyes
is smooth. Fin-rays, dorsal 65-78, ventral 50-62. The colour
is a rather light brown with no distinct markings in the dead
fish, but during life spots arranged like those of the plaice, but
smaller and not red, can usually be seen.

Szze-—On the east coast of Scotland the extreme limits of
size of mature females are 54 inches and 17 inches, of mature
males 4 inches and 16 inches. The average size of the males
was 8:1 inches, of females 8:9 inches. During the Irish Survey no
dabs were taken over 14 inches long. At Plymouth also the
average size is 8 to 9 inches.

Names.—Common dab, sand dab, salt-water fleuk (Edin-
burgh).

Hlabitat—From the Bay of Biscay to the north coast of
Europe ; absent from the Mediterranean and from the American
side of the Atlantic. It is abundant on the shores of Iceland,
of the Orkney and Shetland Islands, and everywhere around the
British coasts, as well as in the Baltic.

The dab has a wide range in depth and saltness of water ; it
is found in abundance with plaice and flounders in the lower
parts of estuaries, though not ascending so far up as the
flounder, and it is common in the open sea up to the depth of
50 fathoms. It is more abundant at depths less than 35 fathoms
than at those greater.

food.—¥ rom the examination of the stomachs of 579 speci-
mens, taken in the Firth of Forth, it was found that crustacea
formed the principal food. They occurred in 48 per cent. of the
stomachs. The commonest kinds were hermit crabs of various
species, swimming crabs and various “ hoppers” (z.e. Amphipods).
Next in abundance of the animals swallowed were of the class
of echinoderms, namely, sand-stars and brittle-stars, which were
found in 21 per cent. of the stomachs. Molluscs were less
commonly present and included the common clam (Pecten
opercularis), razor shells (So/en), and various other bivalves.

224. MARKETABLE BRITISH MARINE FISHES

Worms occurred in only 16 per cent. of the specimens, and
fish, usually sand-eels and small herrings, in only 5 per cent.

In St. Andrew’s Bay the order of importance of the different
kinds of prey is different. Here echinoderms and worms form
the staple diet, each occurring in 43 per cent. of the stomachs,
while crustacea were only present in 22 per cent. and molluscs in
18 per cent. This is an instance of the influence of locality ;
the bottom of St. Andrew’s Bay is entirely occupied by sand
and muddy sand, and the most abundant of the lower animals
are the sand-stars and the lug-worms and tube-worms (Tere-
bellids).

The females (east coast of Scotland) are both larger and
more numerous; the proportion in numbers is 295 females to
100 males, nearly three times as many; in size, 103 to 100—a
very slight difference.

Time and Place of Spawning—On the east of Scotland the
majority spawn in April, May, and June, though a few are ripe
in February, March, and July. On the west of Ireland the
principal months were March, April, and May; on the south-
west coast of England the spawning period covers the same
three months.

It has been generally observed that ripe dabs in the spawn-
ing season occur almost everywhere, there is no evidence of a
movement to particular grounds or particular depths at the
spawning season. This statement does not apply to estuaries
where the water is brackish, and where full-grown dabs are
only abundant in summer and autumn, when they are not
spawning.

The total number of eggs in three ripe specimens was ascer-
tained by Dr. Fulton ; in one 7} inches long the number was
79,194, in another 84 inches 128,812.

The Eggs and their Development.—The egg is like those of
the plaice and flounder, but smaller than either; it is only
‘8 mm. in diameter (;225ths of an inch), and is therefore one of
the smallest of the eggs of the British flat-fishes. Eggs of the
dab were artificially fertilised by the author in May 1886, on
board a steam trawler six or seven miles to the east of the Isle
of May, and developed and hatched in the little Marine Station
at Granton. Hatching took place on the third day at the
temperature of 45° to 60, but at St. Andrews at the beginning

DE eA HTS re iA Min 225

of May, according to McIntosh and Prince, the larve did not
escape from the egg until the twelfth day; the difference
is due to difference of the temperature at which the eggs
were kept.

The newly hatched larva was 2°66 mm. long (a little more
than ;45th of an inch). Its chief distinction as compared with
the larva of the flounder is that the coloured pigment is lighter,
being of a lemon-yellow tint instead of chrome yellow. At first
there is no pigment on the fin-membrane. Professor McIntosh
kept the larve alive at St. Andrews for eleven or twelve days,
and gives a figure of one eleven days old. The yolk was then
all gone, the mouth and jaws were well developed, and there
was pigment on the fin membrane. The pigment was present
all along the tail, not forming a distinct band as in the flounder.

The subsequent stages of this fish taken at sea are difficult
to distinguish with complete certainty from those of the plaice.
Numbers of little flat-fishes belonging to one or both of these
species in all stages of their transformation from 9 mm. to 32
mm. in length (less than 4rd inch to 1} inch) were taken in the
month of May during the Irish Survey at depths from 1 to 32
fathoms. They were captured in tow-nets attached to the
trawl-beam. Mr. Holt has figured a series of stages considered
by him to belong to the dab. They are distinguished from the
similar stages of the plaice by the following differences: the fish
in the same stage of the rotation of the eyes is longer than the
plaice, the body is not so broad in proportion to its length, that
is the little fish is more slender in form, and the eye is some-
what larger in proportion to the head. Considering that when
first hatched the larva of the dab is little more than half the
length of that of the plaice, it is singular that it should be longer
than the plaice during the process of transformation. There are
no definite peculiarities by which in these stages the plaice and
dab can be distinguished. The red spots of the plaice are not
yet distinctly developed, and the lateral line is not to be detected,
so that the curve in it which distinguishes the older dab is not
available. The young flounder can be recognised with certainty
by the number of the fin-rays, but the plaice and dab in the
adult condition agree in this particular, so that it is of no use to
count the fin-rays of the young specimens in order to discover
whether they belong to the one species or the other.

Q

226 MARKETABLE BRITISH MARINE FISHES

In June and July, 1891, twenty-one specimens of the young
dab ranging in size from 1°05 to 3°4 cm. (445 to 144; inch) were
taken in Cawsand Bay and Whitsand Bay, near Plymouth.
Small specimens continued to be taken during the autumn and
winter until the following April: the size of these was from I
inch to 3'7 inches, and all could be considered to be derived
from the previous spawning, that is to say to be one year old or
less. On May Ioth in the Cattewater specimens 14 inch to 33
inches were taken, and even the smallest of these must have
been hatched the previous year. Thus in this species we have
evidence as in others that some specimens hatched in one season
are found in the following spring at a very small size, having
grown very slowly during the autumn and winter.

The following observation on the growth of young dabs in
the aquarium was made at Plymouth. From September 29th to
October 12th, 1891, forty-eight specimens were collected from
Plymouth Sound: they varied from 4 cm. to 6°5 cm. in length
(12 inch to 22 inches). They were kept in a tank measuring 5
feet by 25 feet in area, and 1 foot 6 inches in depth, and were
fed on worms, &c. Measured on March 21st, 1892, they were
found to be from 5 cm. to 12°2 cm. in length @ inches tow
inches). None of them showed any signs of sexual maturity.

On March 3rd, 1893, twenty-three fish survived in this experi-

ment, and these were measured and examined with the follow-
ing results :—

There were fourteen females 4} inches to 84 inches long.
Do. nine males 42. doy to: 7 do.

Two females 74+ and 8} inches long were ripening, but no
others showed signs of sexual maturity: as they were examined
only once however during the spawning season too much stress
must not be laid on this.

The immature dabs after the larval period are, like the adults,
scattered over wide areas and found at nearly all depths. They
are not taken in very large numbers in the marginal waters with
the young plaice, but with a net of sufficiently small mesh they
may be taken at depths of 3 to 35 fathoms.

The food of 175 young dabs 14 inch to 3? inches long was
examined in Lancashire: the fish were all taken in less than 10
fathoms. Forty-six of the stomachs contained food, in twenty-

THEY FLAT-FISH FAMILY

iS)
LS)
~y

nine were molluscs, in twelve crustacea, in four worms. The
molluscs were chiefly the bivalve Scrobicularia, which is
common on the Lancashire coast.

The Flounder (Pleuronectes flesus).

Distinguishing Characters —Rough spiny tubercles ina single
row along the bases of the dorsal and ventral fins, and about
fhe viront ‘end! of the. lateral ‘line... These are enlarged scales,
the other scales are small and smooth, and not projecting from
the skin) Ghe head is rather: laree, like that of the. plaice,
but without the tubercles on the ridge behind the eyes which
are present in the latter. The teeth are conical and pointed.
The fin rays are fewer in number than in any other species of
Pleuronectes, namely, dorsal 60 to 62, ventral 39 to 45. The
colour is a dark brown or nearly black, without distinct mark-
ings ; the lower side is a brilliant white.

ae —Dr. Fulton found that ripe males ranged in length from.
6 to 14 inches, the average being 8°5 inches; females from
7 ton 7s inches) the avetage 113 ‘inches ; the largest female,
mature but not ripe, was 18 inches long.

Names.—F luke is applied to this fish as well as to plaice
and dab; in Morecambe Bay it is distinguished as white fluke,
in Scotland as the “ fresh-water fleuk.”

Hlabitat—Occurs on the European coast from the Mediter-
ranean to the Baltic and shores of Scandinavia. In the
Mediterranean it is usually smooth, the tubercles not being
developed, while in the Baltic they are more developed than on
the English coast. It is not found on the American side of the
Atlantic or in the Pacific.

Of all the British flat-fishes this species is the least marine
in its distribution. It belongs essentially to estuaries, ascending
into fresh water in many rivers when there are no natural or
artifical barriers to obstruct its passage. It is common and in
most estuaries abundant, and there is no estuary in the British
Islands in which it does not occur. However I know of no
instance in which it is found in fresh water cut off from com-
munication with the sea, unless artificially introduced; it can

OR 2

228 MARKETABLE BRITISH MARINE FISHES

live in fresh water, but as will be explained below cannot
propagate in it.

food.—No very extensive investigation has been made of
the contents of the stomachs of flounders ; the marine researches
of recent years have not been adapted to throw light on this
point in the history of this fish. During the Irish Survey
twelve adult flounders, 10} to 15 inches long, taken in Downies
Bay, County Donegal, north-west of Ireland, contained sand-
eels, one shrimp, several /dotea linearzs (a common crustacean),
and one 7Zevrebella, a tube-forming annelid. The observations
of Mr. Thomas Scott on board the Garland were strikingly
unfruitful with regard to the food of this species; of seventy-
five specimens examined in the Firth of Forth during four
years only two contained animals that could be recognised, in
one case worms, in the other a Sol/en or razor-shell. The
reason of this is simply that the Gar/and’s stations were in the
seaward part of the Firth, where only spawning flounders could
be taken, and when spawning the fish do not feed. Buckland
(Report, 1879) states that he found in flounders mussel spawn,
by which he perhaps means young mussels, small shrimps and
worms in sand. Yarrell gives aquatic insects, worms, and small
fishes as the food. In the Plymouth aquarium flounders feed
on rag-worms (/Vervezs) and all other marine worms with great
eagerness, and will also eat scallops (Pecfen) and shrimps, and
other small crustacea.

Buckland (doc. czt.) in describing the flat-fish fishery in More-
cambe Bay, says that the flukes are not present there in the
winter time, that in frosty weather they, especially the white
flukes or flounders, go off into deep water and come back again
in fine weather. But it will be found by reference to the reports
of the Superintendent of the Lancashire Fisheries District
that the migration of flounders in winter is very limited, and
amounts to no more than a departure from the marginal
grounds between tide marks, to the deeper channels, not a
complete removal from the estuaries and bays. This is shown by
the fact that although stake-netting for flounders is abandoned
in winter, numbers are caught even in January in fish trawls in
Morecambe Bay. The most important migration is that of the
spawning fish now to be considered.

The male flounders according to Dr. Fulton’s data are more

THE FLAT-FISH FAMILY 229

numerous than the females, which is the opposite of the usual
case among flat-fishes: there are 62 females to 100 males.
In size the female is larger, as usual among flat-fishes, the
proportion being 126 to 100.

Time and Place of Spawning.—On the east coast of Scot-
land, according to Dr. Fulton, the spawning period extends from
February to the beginning of June, but it is certain that March
and April are the principal months. On the west coast of
Ireland ripe specimens were found in March, and spent fish in
May and June. At Plymouth they spawn principally in
February, March, and April, in the sea. They spawn there
regularly every year in the aquarium, from the beginning of
March to the beginning of May.

Ripe males are occasionally found among specimens taken at
the commencement of the spawning season in estuaries, such as
that of the Tamar, called the Hamoaze, but ripe females never.
In seeking the sea the flounders are limited in their migration,
not by a particular kind of ground or a particular distance from
shore, but by the saltness of the water. They require to shed
their spawn in sea-water, where it will float, although in the
Baltic they spawn in water which is considerably less salt than
that of the North Sea or English Channel. At Plymouth I have
found ripe flounders in great abundance, in the spawning
season, on the trawling grounds inside the Eddystone, from
aboute3 of 4 miles of the land outwards, ~The depths
here are from 15 to 30 fathoms. No flounders are taken on
this ground from the end of May to the end of January.
Outside the 30 fathom line beyond the Eddystone I have fre-
quently studied the contents of the trawl in March and April,
but seen no flounders. Nor have I seen them at the same
season of the year on what are called the Mount’s Bay grounds, to
the south of the Wolf Rock, where the depth is about 40 fathoms.
In the Firth of Forth I have taken ripe flounders in Aberlady Bay
and it was the only species which I obtained in the spawning con-
dition so far up the Firth. The records of Professor McIntosh’s
trawling observations in the Report of the Commission of
1885 show that during the spawning period of the fish, flounders
were taken at depths up to 30 fathoms along the east coast of
Scotland, but not beyond that depth ; they were most abundant
in the hauls made at 44 to 103 fathoms in St. Andrews Bay. On

230 MARKETABLE BRITISH MARINE FISHES

the west of Ireland only one ripe female was taken, and this
occurred at 10 fathoms in Kenmare river. In the Irish Sea, ac-
cording to Professor Herdman’s observations ! spawning flounders
were not found in March on the Bahama Bank, east of the Isle of
Man, 8 to 10 fathoms, but were found in abundance in the same
month ina place called the Hole, just beyond the 20 fathom line.
No spawning fish were found in the Lancashire District within
the three miles limit, where the depths nowhere reach Io fathoms ;
but it seems to me improbable that spawning flounders do not
occur in the proper season on that coast between the 10 and 20
fathom line. However the above summary of the evidence
available is sufficient to show that we have a fairly definite
knowledge concerning the dwelling places and movements of
the flounder. It dwells in estuaries ascending high up the rivers
and haunting the margins of the fluctuating tides in summer and
autumn, retreating to the deeper channels in cold weather, and in
February seeking the open sea in order to spawn, but not
travelling beyond the 30 fathom line, and about Io miles from
the coast. It is not the character of the food on the outer ground
that attracts them, for they do not feed when ripe, and they
leave their usual hunting grounds behind them. There is
probably some physiological peculiarity in them which renders
the expulsion of the eggs difficult in the shallow brackish water,
and the female can only get relief from her burden in deeper,
salter water. The pressure of the developing eggs probably
arouses the desire for greater pressure and greater saltness, and
so we get an idea of the instinct of migration in this case as
similar to the instinct of taking food to satisfy hunger, to relieve
a physiological discomfort.

False notions concerning the breeding of flounders are very
common among fishermen. Shrimpers and fishermen who fish
in estuaries, and who are familiar with the wide expanses of mud
and sand laid bare at ebb tide in such places, usually believe
that the lumps of gelatinous spawn which abound over these
flats in the spring are the spawn of flounders and plaice. These
lumps are of different colours, some green, some pink, some
yellow. They are the spawn of the different kinds of marine
worms which inhabit the sand or mud, and have nothing what-
ever to do with fish. In Buckland’s Report of 1879, this

1 Report for 1893 on the Lancashire Sea Fisheries Laboratory. Liverpool, 1894.

THE FLAT-FISH FAMILY 231

erroneous theory is set down on the authority of the fishermen
of Morecambe Bay, but in his chapter on the spawning of fishes
it is recorded that he hatched some of this kind of spawn from
Herne Bay. The fishermen of the neighbourhood asserted
most positively that these objects were plaice spawn, but
when hatched they proved to be the spawn of a worm. Not-
withstanding all efforts at the instruction of fishermen, this false
belief was still as tenaciously held as ever among the fishermen
of Leigh in Essex, when I lectured there in 1893. Seeing is
believing, and it is the invisible character of floating fish eggs
which makes it so difficult for fishermen to believe in them.
Another erroneous theory of fishermen is that the flounder
carries its eggs on its back. This is known to be true of the
Surinam toad, but it is not true of the flounder. This fish in
certain rivers where the water is fresh or nearly so, is frequently
affected with a curious disease of the skin, which consists in the
presence of a number of small tumours, having somewhat the size
and appearance of millet seeds. These are both scattered singly
and collected in clusters. The disease is mentioned in Day’s
British Fishes, on the authority of Lowe, who observed it in the
river Ouse at King’s Lynn. It has been described by Professor
McIntosh and others in the Reports of the Scottish Fishery Board.
I myself saw numerous cases of it among the flounders taken in
the stow-nets in the Forth at Alloa. The fishermen there assured
me that the little knot-like tumours were the eggs of the fish.
Reversed flounders are very common, that is to say speci-
mens which have the eyes and colour on the left side instead of
on the right. Once, on board a trawler, between the Eddystone
and the land, I noticed that there were almost as many flounders
left-sided as right-sided among a large number caught. The crew
of the boat asserted that the left-sided were males and the right-
sided females ; but I found that each kind included both sexes.
According to Dr. Fulton’s researches, the flounder is the most
prolific fish in British seas in proportion to its size (see p. 69).
The Eggs and their Development.—The eggs of the flounder
are transparent and buoyant, and only distinguishable from
those of the plaice by their smaller size. The egg is from ‘95 to
1:03 mm. in breadth (about z1; inch), and is quite round. They
are to be taken at sea in the tow-net in February, March, and
April, and have been repeatedly fertilised artificially and hatched

to
i)

MARKETABLE BRITISH MARINE FISHES

at Plymouth and elsewhere. The eggs hatched seven days after
fertilisation at Plymouth at a temperature of about 53° (12° C.).

The larva when hatched is 2°5 to 3 mm. long (12 hundredths
~ of an inch). The mouth is not open; the pigment is yellow and
black, and is absent from the yolk-sac and fin-membrane. A
larva two days old (Fig. 59) was found to be 3°56 mm. long (not
quite } inch). The yolk was reduced to half its original size,
and the mouth was nearly but not quite formed. At this stage
the pigment had extended on to the marginal fin-membrane, and
formed a single broad band across the tail, which is character-
istic of the larval flounder. It also formed a less distinct band
at the level of the vent.

At six days of age (Fig. 60) the larva was 3°94 mm. long (not
quite } inch or 16 hundredths), the yolk was all used up, the
mouth was formed, and was at the end of the snout. The band of
pigment across the tail still remained, the pectoral fin was a large
rounded membrane. No indication of fin-rays or skeleton was
yet visible.

These stages have been studied from larve hatched arti-
ficially and kept under observation. The later stages are known
from specimens captured on the shore. At many places young
flounders in various stages of their transformation, and just be-
yond it, occur in great abundance in April and May in the
shallow pools and channels left by the ebb of the tide. They
have been observed and collected at St. Andrew’s in Scotland,
and at Mevagissey in Cornwall. The species can be distinguished
without difficulty by the number of the fin-rays, for these are
formed all at once and not gradually: no other flat fish in
British waters has so few as forty-five rays in the ventral fin.
Fig. 61 shows the structure of one of these young flounders at a
stage in which the left eye has not quite reached the edge of the
head in its rotation, and Fig. 62 shows the later stage in which
the eye is on the edge-of the head.

The young flounders in the third period of life, from complete
development to maturity, are found in rivers, harbours, and estu-
aries, which they never leave until they go to sea for the first
time, to spawn. Details of the experiments on the rate of growth
of flounders have been given in a previous part of this book.
The young fish in the estuaries have not yet been very carefully
studied. At the mouth of the Humber, below Grimsby, during

THE FLAT-FISH FAMILY 233

Mr. Holt’s investigations, a few specimens 24 to 45 inches were
taken in April and May in the shrimp shove-net and horse-trawl ;
these could not be the brood of the year, but belonged to that of
the preceding year. Older specimens, five to tweive inches long,
were taken by the shrimp trawlers.

Professor McIntosh mentions that the food of the young
flounders in the period of transformation consists of young
Gammari (sandhoppers) and similar crustaceans.

The Witch (Pleuronectes cynoglossus).

Distinguishing characters —UHead and mouth smaller than in
the plaice, eyes rather larger. Body elongated and regularly
oval in outline: very thin and flat. No curve in the lateral line
above the pectoral fin. Teeth in a single row: points rather
blunt. The dorsal and ventral fin with more numerous rays
than in any other British species of Pleuronectes: 102 to 115 in
the dorsal, 86 to 97 in the ventral. Scales feebly spinous
on the upper side, smooth (cycloid) on the lower. Colour on
the upper side pale brown without distinct markings : lower side
with some pigment all over giving it a slightly smoky appear-
ance.

Names.—On the shores of the Firth of Forth, and on the east
coast of England commonly known as the witch, a name which
is usually spelt whitches in newspaper reports. It is also called
the craig fluke, and witch sole in Scotland. It has been
called the pole dab, pole flounder, and long flounder by English
naturalists. In Dublin it is called the white sole.

Habitat.—Is confined to the North Atlantic, extending from
the Bay of Biscay to the north coast of Europe, and on the west
side from Iceland and Greenland to Cape Cod. Around the
shores of the British Isles, it is rare in the: English Channel;
fairly abundant in the North Sea, off the west coast of Ireland
and Scotland, off the south coast of Ireland, and in the Irish
Sea. It is a deep water fish, scarcely ever taken at depths less
than 20 fathoms, and ranging to very considerable depths, the
greatest at which its capture is recorded being 732 fathoms off
the south west of Ireland. Mr. Bourne took one at 200 fathoms,
and eight at 70 fathoms. In the lochs of the west coast of

234 MARKETABLE BRITISH MARINE FISHES

Scotland it has been taken at depths between 20 and 100
fathoms.

Szze.—The smallest mature male on the east coast of Scotland
according to Dr. Fulton, was 9 inches long, the smallest mature
female, 13 inches. The largest male was 19 inches, the largest
female, 203 inches. The average size of the mature males was
14°8 inches, of the females 16:9 inches.

food.—In the Firth of Forth 150 stomachs containing food
were examined. Marine worms occurred in 109, or 72 per cent.;
crustacea in thirty, or 20 per cent.; molluscs in twenty-one, or
14 per cent. ; echinoderms in five, or 3 per cent. ; fish in two.
The crustacea were amphipods in sixteen stomachs, common
shrimps in ten. It is evident that the most important food con-
sists of worms, and this fact is connected with the small size of
the mouth of the fish. On the west coast of Ireland the order
of importance of the different kinds of food was the same.

The females are more numerous than the males in the pro-
portion of 260 to 100, and larger in the proportion of 114 to
100. The total number of eggs in the female was found by Dr.
Fulton to be from 473,000 to 883,000, a number considerably
larger than in the plaice.

Lime and place of Spawning —Off the east coast of Scotland
these fish were found to be ripe in May, June, July,and August,
principally in July. On the west of Ireland they were spawning
in May and June. In the Firth of Clyde they were found to be
spawning in June. It has not been shown that these fish repair
to particular spots in order to spawn; it may be said that the
spawning grounds are simply the grounds where the adult fish
are found. On the east coast of Scotland no spawning fish were
taken within the three mile limit, but this is not true for other
coasts. In the Firth of Clyde a number of ripe specimens were
taken between Millport and Fairlie.

The eggs have been studied at Millport and in the Irish
Survey. They measure from 1°15 to I'Ig mm. across, and are
usually quite round; in character they are not different from
those of the plaice, flounder, &c. At temperatures varying from
53 to 68° hatching took place on the sixth day; at lower
temperatures some hatched on the ninth day after fertilisation.

The newly hatched larva is 3:99 mm. long (a little less than
+ inch). It resembles the larva of flounder and dab, but has less

THE ELAT-PISH FAME 235

=<

pigment—none on the fin-membrane. As the yolk is absorbed
the larva grows very long and slender, and the pigment, develop-
ing on the fin-membrane as well as on the body and tail, forms
five transverse bands, as in the lemon dab—two on the body and
three on the tail. These bands are well marked in the larva
when two days old (Fig. 108), when the yolk is not all gone, and
the mouth is not yet open; at this age the larva was 5°9 mm.

ee NE
a TDS cs

Fic. 108.—Larva of the Witch or Pole Dab, two days old, alive and magnified.

long (nearly } inch). The coloured pigment is a pale chrome-
yellow. Mr. Holt kept the larve alive fourteen or fifteen days
after hatching. When about ten days old the larva had ex-
hausted the yolk ; the mouth was open and terminal, the jaws
being well developed, the lower jaw projecting beyond the
snout.

Fic. 109.—Young Witch, a little over 12 inch long, from a preserved specimen. After
Holt.

The later larval stages and transformation stages in this
species have not been seen either in specimens reared in confine-
ment, or in specimens recognised with certainty from the sea.
During the Irish Survey three or four young specimens, which
had already reached the perfect condition, were taken in the
shrimp-trawl off the Skelligs from a depth of 80fathoms. These
were a little more than 12 in. in length, and were obtained on

236 MARKETABLE BRITISH MARINE FISHES

Aug. 19th (Fig. 109). The age of these specimens is difficult to
estimate, but it seems quite reasonable to suppose that they had
been hatched the same season, and were only three or four
months old. The number of fin-rays in them agreed with those
of the adult, namely, in one specimen, dorsal 105, ventral 89.
On the blind side the characteristic pits in the bones of the head
which occur only in this species, were already present. The
pigment still showed the three bands across the body, behind
the abdomen, which are present in the larva.

Three specimens considerably larger were trawled during the
same survey at 144 fathoms, in July. These were from 12°5 cm.
to 15 cm. in length (4% to 5{ in.), and must have been in their
second year. These specimens, and still more the smaller ones
previously mentioned, are somewhat narrower, in proportion to
their length, than the full grown fish.

In the special investigations of the Scotch Fishery Board on
the places where immature fish occur, only two immature
specimens of the witch were taken. One was 9g inches long, the
other 11 inches, and they were taken at a depth of 20 fathoms,
ten miles from the coast. It will be seen that as far as the
scanty evidence goes, the young stages of the life of this fish
are passed in deeper water than that affected by the adults.

The Lemon Dab, or Lemon Sole (Pleuronectes
mucrocephalus.)

Distinguishing Characters——The most obvious peculiarities at
first sight are the colour and shape, the former a rich brownish
yellow, marbled with round and oval spots of darker or lighter
colour, the shape a regular oval. The head and mouth are
very small. The fin-rays are dorsal 85-93, ventral 70-76, more
numerous than in the plaice, but not so numerous asin the witch.
The teeth are conical, rather narrow and blunt. The scales
small and smooth, slightly more developed than in the plaice,
and extending all over the body and head, and on the fin-rays
on the upper side. The lateral line makes a slight curve above
the breast fin, but much less than in the common dab.

Szze.—It is not a large fish. Dr. Fulton’s largest for the east
coast of Scotland was 18 inches long. At Plymouth the largest

THE FLAT-FISH FAMILY 237

female measured 17 inches, the largest male 16 inches. On the
west coast of Ireland the greatest length observed was 15 inches.

Names.—On the east coast of England and Scotland, this fish
is commonly known to fishermen and fish merchants as the
lemon sole. At Plymouth it is always called the merry sole,
which seems to be a corruption of Mary sole, but what was the
original reference to the Virgin Mary, which seems to be implied
by the latter name, we do not know. In some parts of Ireland
it goes by the name of slippery dab, which is very appropriate.
Yarrell called it lemon dabor smear dab. It has also been called
smooth dab, and, in Edinburgh, sand-fleuk. Since it has no
right to claim near kinship with the aristocratic sole, lemon dab
is the best name to use for it.

Flabitat—This fish is a northern species, absent from the
Mediterranean, but distributed from the Bay of Biscay to Iceland
and the north coast of Europe. Adults were not found on the
west coast of Ireland at greater depths than 40 fathoms, but
the young were found at 80 fathoms, and Dr. Giinther has
recorded adult specimens from depths of 40 to 60 fathoms, on
the north-west coast of Scotland. In his remarks on the trawl
fishing off the south coast of Iceland in 1892, Mr. Holt states
that lemon dabs were very scarce. Off the east coast of Scot-
land, they are fairly abundant. According to Professor
McIntosh’s observations for the Beam-Trawling Commission in
1884, these fish were plentiful on Smith’s Bank, off Caithness (18 to
20 fathoms), in Aberdeen Bay, off the Isle of May and St. Abb’s
Head. In the North Sea, south of the latitude of St. Abb’s
Head, lemon dabs are fairly abundant, and on the Channel
trawling grounds they form a considerable as well as valuable
part of the catch. Off the west coast of England they are fairly
common. On all these coasts they are usually more plentiful on
the deeper grounds some distance from the land, at depths
between 20 and 40 fathoms.

Time and Place of Spawning—In the North Sea Mr. Holt
found that lemon dabs were spawning from the latter part of
April to the early part of September, nearly five months of the
year altogether. He found no spent fish until the latter part of
August. The ova of each single female are shed in successive
lots, the production of which occurs at intervals. Further
north ripe females were observed by the author east of May

238 MARKETABLE BRITISH MARINE FISHES

Island on May 22nd, and by Prof. McIntosh in August. On the
south-west coast the author obtained a few ripe eggs from
March 5th to 8th. Fertilised eggs were obtained throughout
April and May. Spawning commences in February, many ripe
females having been observed in the market on February 18th, and
one was also observed as late as July 15th. March, April, and
May are however the principal months on the south-west coast,
so that the spawning is there two months earlier than on the
north-east coast.

No special grounds have been yet observed to be preferred
by lemon dabs in the spawning condition. The ripe specimens
are found on the grounds on which the adult fish are taken at
other times of the year. These fish have not been found to move
towards shallower inshore waters after the spawning season, as
plaice and soles and other kinds do to a certain extent.

The Eggs—The egg of the lemon dab is spherical and
measures after fertilisation from 1°36 to 1°44 mm. according to
observations at Plymouth (,84, to 73%, inch, or a little more
than 4 inch). It is smaller than that of the plaice but larger
than that of the flounder or dab. It can scarcely be dis-
tinguished from these other species except by its size, resembling
them in the undivided yolk and absence of oil globule. Con-
siderable attention was devoted to the study of these eggs at
Plymouth in 1888. The temperature cf the sea in April and
May, near the Eddystone and the Wolf Rock where the fish was
spawning, was from 43°5° to 50. At a higher temperature in
the laboratory, namely 53° to 55°, the eggs hatched six days
after fertilisation. In the sea their development would probably
have taken eight or nine days. In more northern waters the
time required would be somewhat longer. The specific gravity
of the eggs was found to be about 1'024; in water of density
1°025 they floated, in that of density 1°023 they sank to the
bottom. The density of the water about the Eddystone at the
temperatures above given was 1'0267.

The Larval Stages —The larva when first hatched is 3°38 mm.
in length (,,52; inch, or nearly + inch). It is somewhat narrow
and slender in shape. The pigmentation is slight, and consists
of very light yellow and black specks. There is no definite
arrangement of these, they are scattered over the primitive fin,
the sides of the body, and the yolk sac. Fig. 110 represents a

THE FLAT-FISH FAMILY 239

larva two days old. As the larva develops with absorption of
the yolk the pigment becomes more abundant, and by the time
that all the yolk has disappeared it has fallen into a definite
arrangement consisting of five bands across the body. One of
these is behind the eyes, one in the region of the vent, and three
on the tail. Each band is not continuous but formed of separate
patches, three in the hinder bands, one on the body, and one on
the edge of the primitive fin above and below. No trace of
such bands has been made out in the adult fish.

The next stage known in this species is that of a specimen
secured in the bottom tow-net off Tory Island, north-west of
Ireland, at 29 fathoms, during the Irish survey. The fish is
identified by its general appearance, and the presence of bars of
pigment like those described in the previous stage with an ad-
ditional patch at the end of the tail. The jaws are well

yey SG ying

Fic. 110.—Larva of Lemon Dab, or so-called Lemon Sole, two days old, alive and
magnified,

developed, and the abdominal region is shortened. The two sides
are still alike, except that the left eye has just begun to move
towards the edge of the head. The primitive fin above and
below the hinder region of the tail remains without bones, but
there is a commencement of the formation of the fin-rays of the
tail at the hinder end on the ventral side. This specimen was
10°37 mm. long (just over 2 inch). It was taken in the month of
April. A number of specimens of an older stage were taken
in the shrimp trawl at 80 fathoms in August off the Skelligs,
south-west of Ireland. These were about 27 mm. long (just over
1 inch) (Fig. 111). They had almost completed their trans-
formation, and were recognised as young lemon dabs from their
resemblance to the adult, and from certain of the distinguishing
characters which were already developed—for instance, the number
of the fin-rays. The shape of the body was characteristic, the

240 MARKETABLE BRITISH MARINE FISHES

peculiar oval shape of the lemon dab. The left eye had not
reached its final position, but was on the edge of the head. The
pigment formed five well-marked bands across the body as in
the stages previously described. These bands were scarcely in-
dicated on the central region of the right side, but marked by
distinct patches on the outer parts and on the fins. The fin-rays
were well developed in all the fins—the pectoral, the pelvic, the
dorsal and ventral, and the tail fin.

These fish are probably from two to three months old. It is
remarkable that none of these later larval or transformation
stages have ever been taken except on these occasions during the

Fic. 111.—Young Lemon Dab in last stage of transformation, slightly more than I inch
long. From a preserved specimen ; after Holt.

Irish Survey. Corresponding stages of other kinds of flat fish
are to be obtained without much difficulty at the margin of the
sea in harbours, estuaries, or bays at low tide. But no specimens
of the lemon dab in these stages have been found in such situa-
tions. It need not be concluded however that they only occur
at depths approaching 80 fathoms. On the south-west coast of
Ireland the declivity of the bottom is very rapid, and it is highly
probable that in the English Channel or the North Sea the later
larval stages of the growth of this fish are passed on grounds only
somewhat deeper than those where the adults live. They may
be even on the same grounds. It is to be remembered that such

THE PLAT-FISH PAMILY 241

minute specimens are only to be taken with a shrimp trawl, and
that the opportunities for the use of this trawl by naturalists
in deep water at some distance from the coast have been very
limited.

For some time specimens of the lemon dab in the third
stage, from complete development to sexual maturity, were
almost as unknown as those in the developing or second stage.
In the course of the extensive trawlings of the Garland with a
small-meshed trawl, Dr. Fulton only obtained three specimens
2 inches long, and these were taken on the Smith Bank, at a
depth of 20 fathoms, in March and May. It may be noted that
these specimens must have been hatched in the preceding year,
since there had been no spawning the previous autumn and
winter. They must have been, therefore, at least six months
old, and may have been ten to twelve months.

Recently, however, immature lemon dabs have been dis-
covered in large numbers on inshore grounds. In the beginning
of October, 1892, Mr. Holt obtained a few small specimens from
the Humber estuary, and subsequently, when trawling from a
steam yacht between October 19th and November 17th, he
obtained some specimens in almost every haul. The largest
number in one haul was sixteen, others yielded eleven or twelve,
others not more than seven. ‘The usual size of these was 23 to
34 inches, a few were of larger size up to 83 inches, and one was
11 inches long. It is impossible to be quite certain as to the
age votthese fish. ihe experiments on the growth of the
flounder have shown that a fish twelve months old may be no
larger than another at six months. The lemon dab, in the
neighbourhood of the Humber, begins to spawn at the end of
April. Comparison with the flounder shows that fish spawned
then might possibly reach a length of 2$ to 34 inches by the
end of October. But it is also possible that these fish were at
the beginning of their second year. On the whole with regard
to the smallest fish it is more probable that they were derived
from the preceding spawning season.

At the beginning of June, 1894, the author, taking a trip on
board a shrimp trawler belonging to Brightlingsea, in Essex,
was surprised to find among the small fish captured in the
trawl a very large number of young lemon dabs. The ground
fished was in the Wallet, the first haul being just outside Colne

R

Bar, not far from the shore, at a depth of 2 to 5 fathoms.
Two other hauls were taken further castward with a similar
result. The lemon dabs were 3 to 5 inches long, and there were
a few larger fish of the same species, but the number of these
was insignificant. With the lemon dabs were also taken
hundreds of small soles of the same length, and a large number
of plaice and common dabs of corresponding sizes. There can
here be no reasonable doubt that there was a large assemblage
of year-old fish feeding at the bottom of this inshore, almost
estuarine, channel. Whether the occurrence of yearling lemon
dabs at this particular locality is exceptional or not we do not
yet know. At present the observation, as far as this species is
concerned, is unique.

The Halibut (17ppoglossus vulgaris).

Distinguishing Characters—Body thick and narrow, ap-
proaching to the shape of an upright fish. Dorsal and ventral
fins rather narrow, especially in front and behind: both end at
some distance from the tail. Dorsal commences above the
upper eye. Mouth large: teeth on both sides of the jaws, a
double row in the upper jaw. Skin smooth, scales without
spines (cycloid). Colour, nearly uniform dark olive, with a slight
marbling of darker. Lateral line with a curve above the pectoral
fin.

Szze—The halibut is by far the largest of all the flat fishes,
not only of Europe but of all the world. Specimens are said to
have been taken which were nearly 20 feet long. European
specimens 74 feet long and weighing 320 lbs. have been authen-
tically recorded. Specimens from six to seven feet long are
common in the Grimsby market, though the majority captured
range from two to six feet.

Names.—Generally called halibut or holibut, which latter
is the usual pronunciation on the east coast of England. Called
turbot in the Moray Firth.

Flabitat.—It is a northern, it may almost be said Arctic, fish.
In Europe its southern limit is the English Channel. It probably
exists all along the southern shores of the Arctic Ocean—Euro-
pean, Asiatic, and American. It is known to occur off the coasts

THE FLAT-FISH FAMILY 243

of Spitzbergen, Norway, Iceland, Newfoundland, Alaska, Cali-
fornia, and Kamtchatka. It thus occurs on both sides of the
North Atlantic and North Pacific. It is most abundant at
considerable depths, 50 to 120 fathoms. The chief sources of
the supplies of halibut landed at Hull and Grimsby are the
Iceland and Far6de banks, where they are caught with long lines.
They are carried alive in the wells of the vessels, each being tied
by the root of its tail to facilitate removal when the fish reaches
port, and because by this method a larger number can be kept
alive. Off the east coast of Britain halibut are fairly plentiful as
far southwards as the Great Fisher Bank, and a few are taken on
the shallow grounds off the German and Dutch coasts. Single
specimens have been occasionally taken off the coast of Corn-
wall. During the Irish Survey three specimens were taken, two
on long lines, one in the large beam trawl, in depths of 17 to 35
fathoms. They were fairly large specimens, 29 inches to 3 feet
in length.

Food—The halibut feeds on fish and crustaceans.

Time and Place of Spawning —At Grimsby Mr. Holt observed
a ripe female in April and one in August, but noticed fish in
September whose condition seemed to indicate that they would
have spawned in autumn; these were from Iceland. On the
west coast of Ireland a spent specimen was observed in July.
On the testimony of Fishery Officers on the east coast of Scot-
land ripe specimens occurred in March, May, and June, From
this evidence we may conclude that the fish spawns from April
to August, and that the period may be somewhat extended in
both directions.

The Eggs.—The character of the ripe and fertilised eggs has
only, recently been discovered. On April 30th, 1892, Mr
Holt obtained some ripe ova by pressing the abdomen of a
female in the market at Grimsby. The eggs were dead, but
the transparency and uniform character of the yolk showed
that they were ripe. These eggs were 3:07 to 381 mm. in
diameter (the largest over =, or 3% inch). The yolk
was like that of the plaice or flounder, colourless, transparent,
and undivided, and there was no oil globule. It was evident
that the eggs were of the floating kind, although not being alive
they did not float. No floating eggs so large as this have yet
been taken in the surface nets at sea, probably because such

R 2

244 MARKETABLE BRITISH MARINE FISHES

nets have not been worked at a sufficient distance from the coast,
in the proper regions. Mr. Holt suggests that the egg when
alive in sea water may develop a large space within the enclos-
ing membrane, as in the egg of the long rough dab, which is
closely allied to the halibut. The egg-membrane was very thin
and easily burst. Subsequently in the same year Prof. McIntosh
examined two samples of ripe eggs of the halibut, one sample
taken at Peterhead from a fish which had been three days on
board, and which had been captured on Bergen Bank about 60
miles off the Fair Isle. The fertilised eggs have not yet been
obtained, nor any of the larval or very young stages. From
observations made in Grimsby market Mr. Holt found that the
smallest ripe males were 30 inches long, the smallest females
nearly ripe were 43 inches long.

The Long Rough Dab (//:p/og/ossoides limandotdes).

Distinguishing Characters—Resembles the halibut in shape,
but the head is broader in proportion to the body. It differs
from the halibut in having a rough skin, the scales being
furnished with spines on their hinder edges. The mouth is
large, the jaws nearly equal on the two sides of the head.
Teeth pointed, one row in each jaw. Lateral line straight,
having no curve above the breast-fin. The eyes are larger in
proportion than those of the halibut. The colour of the upper
or right side is a brownish-gray, usually without any spots or
markings.

Size-—Dr. Fulton found that off the east coast of Scotland
the smallest ripe male was 5 inches long, the largest 8 inches,
but nearly ripe males were from 4 to 12 inches. The average
length of mature males was 6°5 inches. The smallest ripe
female was 5 inches long, the largest 164 inches, the average
length was 8°8 inches.

Names.—It is sometimes called simply the rough dab, but
no other local names have any importance. It is known as
smeareen in Dublin, long fleuk and sand-sucker in Edinburgh.

Habitat.—Like the halibut this is a northern fish, rare in the
English Channel, but extending to the Arctic shores of Europe,
and to all the shores of the Arctic Ocean. It is an inhabitant

EE AGES Ty kA Mane vs 245

of rather deep water, being rarely taken on grounds less than
20 fathoms below the surface. It does not however descend to
creat depths, 80 fathoms being the greatest at which it was
found on the west coast of Ireland. In the North Sea it is not
found on the Dogger Bank or on the shallow grounds of the
eastern side and south of the Silver Pit. It is common along
the east coast of Scotland and north-east coast of England,
occurs in small numbers on the deeper grounds off Mount’s Bay
and the mouth of the Bristol Channel. It was found by Mr.
Holt to be common in the produce of the beam trawl on
the grounds off the south coast of Iceland up to a depth of
40 fathoms.

Food of the Adults—In the Tenth Report of the Scottish
Board are given the results of the examination of the contents
of 569 stomachs from the Firth of Forth. The different kinds
of marine animals were found in the following percentages of
stomachs :—crustacea in 49 per cent.; echinoderms in 29 per
Cent; ish in 14 "per cent;; marine. worms im |O) per cent.);
molluscs in 6 per cent.

Among the crustacea, the common shrimp was present in
126 cases, hermit crabs in forty-five, swimming crabs in thirty,
red shrimps in twenty-one, opossum shrimps in twenty-two.

Among echinoderms, sand-stars occurred in sixty-one, brittle-
stars in thirty-five, common starfishes in seven.

Of fish, gobies occurred in seventeen, whitings in five, long
rough dabs (cannibalism) in four, and others in smaller numbers.

The most important prey of this fish in the Firth of Forth
therefore is the common shrimp, other crustacea come next in
order, and echinoderms next

In St. Andrews Bay on the other hand, the echinoderms
predominated. Only sixty-two stomachs examined contained
recognisable remains, and among these forty-nine contained
sand-stars and brittle-stars. Shrimps were found in eleven, fish
in five, and worms in two.

Lime and Place of Spawning—Dr. Fulton found that these
fish were spawning from February until May, chiefly in March.
On the west of Ireland ripe fish were taken in April and May.
On the east coast of Scotland spawning takes place both inside
and outside the three-mile limit, but chiefly outside.

The Eggs and their Development.—The buoyant ova of this

246 MARKETABLE BRITISH MARINE FISHES

species are common off the east coast of Scotland, and became
familiar to naturalists long before it was known to what fish
they belonged. At the latter end of March 1885 and 1886, the
author obtained eggs about ten miles east of the Isle of May,
which were distinguished by the great width of the space within
the egg-membrane. At that time no other floating eggs having
this character had been seen. The egg proper within the en-
closing membrane was similar to that of plaice or dab, having a

simple yolk without oil globule. The breadth of the whole egg,

Fic. 112.—Egg of the Long Rough Dab, alive and magnified.

that is of the spherical membrane, was 2°1 mm. (just over 7b

inch), a little greater than that of the plaice egg. But the egg
proper within the membrane was only 1:2 mm. (about 4, inch).
In the memoir of McIntosh and Prince, published in 1889, the
egg is again described, and also the larva hatched from it, but
its parentage had not been ascertained. The ripe eggs of the
long rough dab were obtained from the fish by Mr. Holt on
April oth, 1891, outside Galway Bay, and were artificially
fertilised. He found that they were the eggs previously dis-
tinguished by the peculiarities mentioned above (Fig. 112). There

THE FLAT-BISH FAMILY 247

is no doubt that when the eggs are shed from the roe of the fish,
the membrane closely envelops the yolk, and the wide space
separating the two is produced when the eggs come into con-
tact with the sea-water. The eggs were not hatched during
the Irish expedition, but stages of the larva are known from the
work of Professor McIntosh and Mr. Holt at St. Andrews.

In the embryo before hatching there is not much black
pigment: the coloured pigment is a pale yellow, distributed
somewhat uniformly over the head, body, and tail region, but
absent from the yolk sac and marginal fin-membrane.

The newly hatched larva is described and figured by Professor
McIntosh in the Seventh Report of the Scottish Fishery Board,
1889, but he gives no measurements. According to Holt’s
observations the egg was nearly ready to hatch when about five
days old. The larva, half a day old, had a length of 3:99 mm.,
or a little less than + inch. The mouth was formed, the pig-
ment extremely faint and without special arrangement. It was
absent from the fin-membrane, and there was no black pigment,
only the yellow.

An older stage is figured by Holt. It was 4°65 mm. long,
less than t inch. The yolk was reduced to about half its bulk
at the time of hatching, and the lower jaw was more developed.
But the most striking change was in the pigment, the yellow
having darkened to a chrome tint, and black specks having
appeared. The pigment, moreover, now formed three distinct
bands across the tail, one behind the other, as in the lemon dab
and witch, but the bands did not extend on to the marginal
fin-membrane.

Of the transformation stages we know nothing with certainty
at present, for among the minute specimens of flat fishes collected
at sea, this species has not been identified, at least not to the
present writer’s satisfaction. But very small specimens in the
perfect or fully transformed condition were obtained in the
course of the Irish Survey. Several were captured in the shrimp
trawl in August 1890, at the depth of 80 fathoms, off the
Skelligs. These ranged in length from 1,4, to 1% inches. On
the following day more were taken at 52 to 62 fathoms in the
same neighbourhood ; these were from 12 to I inches. The
smallest of these specimens is represented in Fig. 113. It will be
seen that in this stage the transformation is very nearly complete,

248 MARKETABLE BRITISH MARINE FISHES

but the left eye still projects somewhat beyond the edge of the
head. The three bands across the tail in the larva are still in-
dicated by black patches opposite to each other near the margins of
the upper or right side. The large size of the eyes, larger in pro-
portion to the head than in the adult fish, is a characteristic feature.
The number of fin-rays agrees with that of the full-grown fish.
The large size of the mouth is another important point in the
recognition of these small specimens. There can be no doubt,
I think, that these fish were derived from the spawning
of the preceding spring, and were therefore from three to five
months old. I is evident, therefore, that the young of the long

Fic. 113.—Young Long Rough Dab, 12 inches long ; after Holt.

rough dab in their first year do not seek the shore and the shal-
lows like the plaice and sole, but are found in deeper water like
the lemon dab and witch. A few specimens taken with those
just considered were about 34 inches long, and were doubtless in
their second year. One specimen taken off the Aran Islands at
30 fathoms, in April, 1891, was 31 inches long, and must be con-
sidered to have been one year old.

During the Irish Survey larger specimens, 6 inches and up-
wards in length, were taken chiefly between 20 and 4o fathoms,
so that it appears that the younger stages of life are passed
by the long rough dab in deeper water than the older, the fish
approaching nearer to the coast as it grows larger.

REE Ee AD ETS Et eA ve 249

The Sole (Solea vulgaris).

Distinguishing Characters —The chief peculiarities of the sole
and other kinds resembling it are the narrow oval shape of the
body, presenting everywhere a regular curved outline, and the
character of the head. The mouth is not at the end of the
snout, but behind it, and the jaws are curved, not straight. The
outline of the snout is semicircular, and the dorsal fin commences
on it in front of the eyes. The eyes are small. No bones are
visible on the head, the scaly skin extending over all parts of
it equally. On the lower side of the head there are no scales,
but a number of short soft processes. The marginal fins
extend to the base of the tail fin, but are not joined on to it.

The common sole is distinguished from others by the follow-
ing points: pectoral fins on both. sides of considerable size ;
that of the upper side with a black spot at its outer end ; nostrils
on the two sides similar ; fin-rays, dorsal 73 to 90, ventral 61 to
74. Colour, brown or greenish-brown, with rows of darker
blotches along the centre of the upper side, and along the
bases of the fins. The usual length is 12 to 18 inches, but
specimens have been recorded up to 26 inches long, and II}
inches broad.

Habitat.—From the Mediterranean to the coast of Denmark
and the Firth of Forth, north of which latitude it is rare. It is
fairly abundant round the coasts of Ireland and in the Irish Sea.
In the Bristol Channel and the English Channel, and also in the
North Sea, it is taken in large numbers by the beam trawl.

The sole is distinctly a shoal water fish. In the Irish Survey
the greatest number were taken between 5 and 30 fathoms, while
a few were taken at greater depths up to 53 fathoms, and in less
up to 5. The most productive sole grounds in the North Sea
and English Channel are from 5 to 40 fathoms in depth.

Food.—The stomachs and intestines of soles examined from
December to March at Plymouth were for the most part empty,
probably because the spawning season was approaching. Thirty-
six were found containing remains of food, and in eighteen these
consisted of marine worms. Small fragments of the shells of
bivalves were present in many, but these seemed in most cases
to have been attached to the tubes of tube-building worms,

250 MARKETABLE BRITISH MARINE FISHES

although small bivalves were sometimes found in the entire con-
dition. The throat teeth of the sole are pointed and slender,
and cannot serve for crushing shells as do those of the plaice.
Twenty-five per cent. of the stomachs contained echinoderms,
mostly sand-stars. Crustacea were only found in II per cent.
On the west coast of Ireland the order of importance of the
different kinds of food was found to be the same: worms were
most frequent, then sand-stars or other echinoderms, then mol-
luscs, then crustaceans, and lastly fish in a few cases. The
echinoderms were mostly brittle-stars or sand-stars, among the
molluscs were small specimens of the razor shell, the crustaceans
were usually small sand-hoppers or shrimps, the fish small sand-
eels.

In the aquarium the sole will eat marine worms, shrimps, and
pieces of fish or molluscs such as queens (Pecten) or mussels :
but it prefers worms. When searching for food, whose presence it
recognises by the smell, it glides gently about over the sand tap-
ping with the lower side of its head in order to feel with the
sensitive filaments there. But it soon gets accustomed to expect
the food thrown into the tank, and often swims up from the
bottom to seize it, although it is not very expert in doing this.
Agitation of a handkerchief in front of the glass wiil cause the
soles to collect to the front in expectation of food. The sole is
one of the flat-fishes most addicted to burying themselves in the
sand or gravel, leaving only their eyes exposed.

[t is much more active by night than by day. This is proved
not only by the unanimous testimony of fishermen that more
soles are to be caught by trawling at night than by day, but by
observation in the aquarium. On a visit after dark the soles are
always found to be out of the sand, moving with some activity
and searching for food, and when a light is directed upon them
they soon bury themselves. As the sole trusts chiefly to the
senses of smell and touch to find its prey, it can obtain food
without difficulty in the dark, and seems in the natural state to
use its eyes but little in hunting, a fact which is in agreement
with the small size and slight mobility of those organs.

It is possible to capture soles by hook and line, but this
method appears nowhere to be employed by professional fisher-
men except at Scarborough. A few men at that port set ground
lines for soles in a little bay called Cloughton Wyke north of

UL
_

THE FLAT-FISH FAMILY 2

the town. The hooks are very small, and the bait used is lug
worms. The fishing is carried on only in summer, the boats
used being open cobles. Along the Yorkshire coast a rocky
bottom extends out from the shore seawards for some distance,
and only beyond it is sandy ground found in most places, but at
Cloughton a narrow strip of sand runs almost to the head of the
Wyke, and the soles are attracted to this spot by the large
number of marine worms to be obtained there.

Breeding —The proportions of the sexes in number and size
have not been so carefully ascertained as in the case of other
species, but there is no doubt that the females are both more
numerous and larger than the males. Inthe Irish Survey, of 414
specimens examined, 245 were females, 169 males, or 144
females to 100 males. The smallest mature female was 2 inches
longer than the smallest mature male. The very small size of
the male sexual organs has already been mentioned in Part I.

Off the coast of Devon and Cornwall the spawning season
extends from the middle of February to the middle of May.
On the west coast of Ireland ripe females were taken in March,
April, May, and June, but principally in March and April. In
the North Sea spawning was observed from the end of April to
the end of July. A sole of one pound weight has been calcu-
lated to contain 134,000 eggs.

Spawning takes place in the deeper water: on the south-
west coast of England, outside the Eddystone, south of the Wolf
rock, off the north coast of Cornwall, and in Mount’s Bay, at
from 20 to 40 fathoms. In the bays and inlets of the west coast
of Ireland ripe females were taken between 5 and 15 fathoms,
and also between 22 and 53 fathoms.

The egg of the sole when fertilised is buoyant, and floats in
sea water: it is 147 to 1°51 mm. in diameter (zg to zé> inch,
or j, inch). It is easily distinguished from the eggs of other
fishes in British seas by the facts that the outer layer of the yolk
is divided into separate segments, and that there are an immense
number of minute oil globules arranged in irregular patches at
the surface of the yolk (Fig. 114).

The larva hatched out on the tenth day at a temperature of
48° to 50. The larva resembles that of other flat fishes, except
in the peculiarities of the yolk ; it is 3°5 to 3:7 mm. long (,%; to #5
inch) ; the coloured pigment is orange-yellow by reflected light,

2 MARKETABLE BRITISH MARINE FISHES

pale when the light comes through it: the pigment is rather
abundant and occurs on the body, yolk-sac, and fin-membrane,
without any particular pattern (Fig. 115).

Fic. 114.—Egg of Common Sole, alive and magnified.

The larva six days old had its mouth fully formed, and the
yolk reduced to half its bulk. Even at this early age the pro-

SERORM Gs rae PO i

Fic. 115.—Larva of Common Sole, newly hatched, alive and magnified.

jection of the snout above the mouth is noticeable, and another
peculiarity is the elevation of the fin-membrane above and just
behind the head. The black pigment forms a row of spots on

THE EUAT-BISH FAMILY 25

i>)

the dorsal fin-membrane. Fig. 116 shows the appearance of the
larva at this stage.

A stage in the transformation of the sole was seen in a speci-
men taken with a hand-net amongst the seaweed on Plymouth

if
seen een e

REY
PARE

Fic. 116.—Larva of Common Sole, six days old, alive and magnified.

Breakwater (Fig. 117). The left eye is still on its own side, but
very near the edge of the head. The specimen was II mm.
long (,45 inch). It differs from the corresponding stage of
the flounder by the great length of the dorsal and ventral
fins, which behind reach to the base of the tail, and the dorsal
in ikont 41S almost projecting over the rising left eye. The

HS

Zi Hf

TY / Thal il

WYP Yee:
Wf,

Fic. 117.—Transition stage of Common Sole, alive and magnified ; a. 4. air bladder.

fin-rays and skeleton are well developed. Other peculiarities
are the breadth of the abdominal region, and the presence of a
rather large air-bladder which is entirely wanting in the full-
grown sole. The pigment forms obscurely-marked spots.

254. MARKETABLE BRITISH MARINE FISHES

This is the only specimen of the sole in the period of trans-
formation yet obtained in Britain ; it was taken on August 9th,
and such stages must occur somewhere at an earlier date in the
year. They have not been seen at the surface like the young
turbot and brill, nor at the margin at Jow tide like the flounder,
nor have been captured near the bottom like plaice and dabs.
As they have an air-bladder it is probable that they swim near
the surface, or far from the bottom.

The next stage of the sole which is known is that in which
the transformation is just complete, and the little fish is very
like the adult, but more Cesipererih This stage is represented
by specimens 12 to 15 mm. long (+2 inch to 2 inch) taken to the
number of fifteen at one time from the end of April to the middle

Vs
ps aan

Fic. 118.—Young Common Sole, just after its tranformation, alive and magnified.

of May in the tide-pools of Megavissey Harbour, in Cornwall.
They had lost their air-bladder. Their ages may be reckoned at
about two months (Fig. 118). They were very much scarcer than
the flounders taken with them, and also somewhat older, that is to
say more advanced in development. It is evident that the soles do
not seek the marginal region at so early a stage as the flounder.
Young soles between the end of their transformation and one
year of age have not yet been frequently observed in large num-
bers. At Plymouth and along the Cornish coast I searched for them
from time to time in the course of several seasons without success.
A few specimens less than 2 inches long were trawled by Mr.
Holt at the mouth of the Humber, in October and November,
and these in all probability were derived from the preceding

ee

THE FLAT-FISH FAMILY 255

spawning season in the same year, and were therefore about five
or six months old. In September, 1895, I saw some hundreds
of small soles 2 to 24 inches long brought up in the trawl of a
professional shrimper working on the Newcome Sand, off Lowes-
toft. The depth was 14 to 2 or 3 fathoms, and the number of
these young soles at each haul varied from 20 to 100. The
other contents of the net consisted of shrimps, a few larger soles
6 to g inches long, a few plaice about the same size, and a con-
siderable number of small whiting 3 to 12 inches long. Plaice
and dabs as small as the small soles were very scarce. Besides
the fish there were quantities of zoophytes and various worthless
fish, namely, weevers, gobies, pipe-fishes, &c. There were also
some star-fishes, swimming-crabs, shore-crabs, sand-hoppers, and
bivalve shell-fish.

In tracing the history of young soles it is very important to
distinguish them accurately from specimens of the solenette,
which are about the same size, and at first sight extremely
similar in appearance. In fact both fishermen and fish merchants
constantly mistake the solenettes, which are frequently taken by
the large beam trawl on many of the North Sea fishing grounds,
for young soles. In the long course of my experience I have met
with only one skipper who held the opinion that the solenette
was a distinct kind of fish from the sole, and he was not aware
of the exact points of difference between them. The solenette
can always be distinguished by the absence of the breast-fin,
and the black lines on the marginal fins. The young of the
common and valuable sole has only been taken hitherto in
shallow water near shore, while the solenette is often found in
the crevices of the ground rope on the grounds of the southern
and eastern parts of the North Sea, many miles from land, where
the depth is less or not much more than 20 fathoms.

The smallest soles taken in the shove-net at the mouth of the
Humber in April, were 2% inch to 32 inch long, and occurred
only in small numbers, four in one haul. These were evidently
the produce of the preceding season, and might be from 8 to 12
months old. Five taken in May were 2} to 42 inches long, four-
teen in June 24 to 434% inches, five in July 3§ to 7} inches long.
We have various reliable descriptions of the numbers and kinds of
small fish taken in shrimp-trawling. At Plymouth I have never
seen large numbers of year-old soles taken in the small beam

256 MARKETABLE BRITISH MARINE FISHES

trawl used for shrimps. Dr. Fulton found that in the Solway
Firth in June only eleven soles, 2} to 6 inches long, were taken in
five: hauls, the depth of water being 3 to 1; feet) On the
Lancashire coast a great deal of inshore fishing goes on, including
shrimp trawling, and yearling soles, 3 to 6 inches in length, are
taken in considerable numbers. The proportion however in
number of these to small plaice is not great, the lowest was
4 soles to 900 plaice, and the highest 136 soles to 520 plaice.
The fishing is carried on chiefly in the summer months, at
depths from 3 to 10 fathoms. That yearling soles do occur
sometimes in large shoals, in inshore waters, is proved
by an observation made by myself, on the Essex coast. There
on board a shrimp trawler, fishing in the Wallet, from Colne
Bar up to Clacton, in the beginning of June, I saw very large
numbers of small flat fishes brought up with the shrimps, and
although plaice and dabs were most abundant, there were many
hundreds of small soles 3 to 5 inches long, and also many lemon
dabs. There can be no doubt that these soles were the produce
of the preceding season. As all the flat fishes were culled out
by hand and thrown overboard, there was no great destruction of
the valuable soles, which are not injured by such a course of treat-
ment, provided they are not kept on the deck of the boat too
long.

A few soles may possibly reach a length of 8 inches, when
one year old, but it is pretty certain that the great majority at
that age measure between 3 and 6 inches. It appears from the
evidence summarised above, that soles in the first year of life
are confined to inshore waters, to depths less than 10 fathoms.

Immature soles above 6 inches in length, do not seem to
frequent different grounds from those on which the full-grown
fish are found. Both the immature and the mature after spawning
are found, especially in summer, on inshore grounds, and in
estuaries up to a considerable distance from the sea. Thus four
were taken in july at Malpas in the Fal estuary more than ten
miles from the sea. In the Humber in May small boats get as
many as thirty from 7 to 10% inches long, in a night’s fishing,
and larger spent fish are taken there in July, August, and
September.

Size at which Maturity is reached.—There seems to be no great
difference between the size at which soles begin to breed in the

THE FLAT-FISH FAMILY

No
UL
ay

North Sea and off the coasts of Devon and Cornwall. The
smallest mature females observed at Grimsby were 10 inches long,
at Plymouth 12 inches, the largest immature 12 inches at Grimsby,
13 inchesat Plymouth. The smallest mature males were 8 inches
long at Grimsby, 9 at Plymouth. Considering the difficulty of
the question, it cannot be said that the largest size of immature
males has been determined with certainty.

Migrations and Habits.—It is questionable whether any soles
remain in estuaries, or in very shoal water in the coldest time
of the year. A few were taken in the Humber below Grimsby,
up to November 17th, but they are much more abundant
there from May to September. Spawning fish are not found,
generally speaking, at less than ten fathoms, and are usually
found beyond twenty fathoms. As far as the evidence goes, it
may be concluded that there is a general movement of all soles
in very cold seasons to deeper water, and of immature and spent,
that is feeding-fish, to the shallower waters in the warmer periods
of the year.

The Sand Sole, or French Sole (Solea /ascaris).

Distinguishing Characters ——Both pectorals well developed as
in the common sole, but the front nostril on the blind side much
enlarged, fringed on the outer edge and with folds on the inner.
The fin-rays are usually somewhat fewer in number than in the
common sole, dorsal 79 to 89, ventral 67 to 71. The scales are
larger. The dorsal commences further forwards, on the extremity
of the snout. The colour is brighter, yellowish, with small black
spots without definite arrangement, and gold specks. In size it
is somewhat smaller than the common sole, usually 8 to 12 inches,
and not known beyond 14 inches.

Names.—This species is sometimes called the lemon sole,
but it is quite different from the lemon dab, which is commonly
called lemon sole.

Habitat.—From the shores of England and Ireland to the
Mediterranean, and probably farther south. It is scarce in
British waters, commoner in the Mediterranean. Has been
taken as far north as Banffshire, occasionally taken in the
southern part of the North Sea, English Channel, and Irish

S

258 MARKETABLE BRITISH MARINE FISHES

Sea. Three specimens were taken in the Irish Survey, in
shallow water, 14 to g fathoms, in April. Three specimens
under 8 inches in length were taken in Whitsand Bay, near
Plymouth, in June.

The eggs and young have not been traced.

The Solenette, or Little Sole (So/ea lutea).

Distinguishing Characters——TVhe pectoral or breast fins, and
the pelvic or throat fins very small, represented only by slight
rudiments. Dorsal fincommences on the extremity of the snout,
contains 65 to 73 fin-rays; the ventral fin contains 50 to 63;
these numbers are fewer than in the common sole. The scales
are larger than in the latter. The colour is yellowish-brown,
with dark spots arranged as in the common sole, but there are
black lines at regular intervals on the marginal fins, each corre-
sponding to a fin-ray. Does not grow to more than 5 inches in
length.

Habitat—Extends from the Mediterranean to the north of
Scotland. It is fairly common all round the British and Irish
coasts, but usually confounded with the young of the common
sole, although it can be distinguished with complete certainty at
any size. Off Plymouth it has been taken at depths up to
20 fathoms, on the west of Ireland up to 38, in the North Sea
it is common on various grounds; for instance, the eastern
grounds and the Brown Ridges, up to about 20 fathoms.
Specimens are very often found in the crevices of the ground
rope of the trawl. Ata length of 2 inches to 34 inches it is
common in Cawsand Bay, Plymouth Sound, where adults 4 to
5 inches long are also taken. It has not been found in the
Humber estuary, probably because it avoids brackish water.

Breeding.—The females are larger and more numerous than
the males, the former becoming mature at 34 inches, the latter at
3 inches or less.

The egg has not been fertilised from the fish, but buoyant
eges obtained by the tow-net in the Irish Survey, and resembling
those of the thickback, only much smaller, probably belonged
to this species. The larva when first hatched was just over
3's inch (2°02 mm.).

THE FLAT-FISH FAMILY 259

The Thickback (Solea variegata).

Distinguishing Characters—Pectoral fins very small, rudi-
mentary. Mouth straighter and nearer the snout than in the
other species. Marginal fins do not reach the root of the tail.
Fin-rays about the same number as in the solenette. Colour,
brownish-red with five dark bands across the body, the ends of
which bands on the fins are black. Grows to 84 inches in length.

Flabitat—From the Mediterranean to the British Islands.
It is common off the coasts of Devon and Cornwall. Only one

”

wee “ oe ot"

iu t
DLT OE

\ > e

Seu ae "5

Fic. 119. —Newly-hatched larva of the Thickback, alive and magnified.

was taken in the Irish Survey, but it has been obtained on the
west of Scotland. It is not found in the North Sea or on the
east coast of Scotland usually, although said to have been taken
off Banffshire.

It is a deep water species, at least in our latitudes, not
having been taken in less than 20 fathoms, and it was trawled
off the south-west of Ireland at 150 fathoms. Off Plymouth
it is abundant to the south of the Eddystone, in from 30
to 40 fathoms.

The females are more numerous and larger than the males ;
in one lot there were 179 females to 34 males, or 526 of the
former to 100 of the latter.

They were spawning freely south of the Eddystone in April.

S2

260 MARKETABLE BRITISH MARINE FISHES

The eggs have been taken from the fish in the ripe condition,
and also obtained in abundance from the sea. They differ from
those of the sole chiefly in the fact that the oil globules are
larger and scattered singly and separately over the surface of
the yolk. The egg is 1°36 mm. in diameter (a little more than
= inch). The larva when first hatched (Fig.119) resembles that
of the sole, but the pigment is lighter ; the larva is 2°42 mm. in
length (not quite j!5 inch), considerably smaller than that of
the sole.

Intermediate stages have not been seen. The youngest
fully developed specimen obtained was 1°8 inch long, taken, in
July, two miles north of the Eddystone. This specimen was
possibly only three months old, but more probably a year.

The Turbot (Rhombus maximis).

Distinguishing Characters—FEyes and colour on left side,
body very broad, mouth large, teeth and jaws on the two sides
equal. Distinguished from the brili by the greater breadth of
the body in proportion to the length, the absence of scales, and
the presence of scattered, large, bony, blunt tubercles. The
fin-rays are few in number, dorsal 61 to 72, ventral 45 to 56.
Colour in life speckled, light or dark according to the bottom it
lies on: after death a dark brown somewhat mottled.

Size-—The average length of the mature males, according
to Dr. Fulton, is 17:2 inches, the dareest. 24 inchesi-von ue
mature females the average 20°3, the largest 28 inches. A male
26 inches long, weighing 14 lbs., was taken during the Irish
Survey. Buckland records a turbot which weighed 32 lbs.

Habitat—A rather southern fish, extending throughout the
Mediterranean and Black Sea, and northward to the latitude of
Denmark and the southern part of Scotland, north of which it
is rare. It does not exist on the American side of the Atlantic.
It is rare on the coasts of the Orkneys and Shetlands, absent
from Iceland. It was taken in considerable numbers during the
Irish Survey on the west coast of Ireland, and occurs also on
the north-east and south coasts. In the English Channel it
forms an important part of the produce of the trawl fishery.

It is a shallow water fish. None were taken on the west

7
]
7
{

THE FLAT-FISH FAMILY 261

coast of Ireland at depths beyond 40 fathoms, and even the
larger specimens are often taken in 3 to 10 fathoms, a short
distance from the beach. It does not however ascend estuaries,
in the adult state, though a few young are taken in the lower
parts by shrimpers.

Food.—The turbot, especially when of considerable size, feeds
almost entirely on other fish. It is a predaceous creature, whose
powers of concealment by means of covering itself with sand,
and assimilating its colour to that of the surrounding ground,
enable it to lie in wait until some fish is near enough, and then
suddenly to rise from the ground and seize it. On the west of
Ireland the principal fish found in turbots’ stomachs from May
to August were sprats and sand-eels (Ammodytes). In one
specimen, 174 inches long, more than sixty sand-eels were
found. A dab, a sole, and a pout (Gadus Esmarkiz), and a
dragonet were also found each once. Bivalve molluscs and
worms were found in one fish each.

On the trawling grounds of the south-west of England I
have found in turbots’ stomachs, the boar fish, commonly called
cuckoo by the fishermen, pilchards, whiting, young sea bream
(Pagellus centrodontus), pout (Gadus luscus}, and never found
anything besides fish.

Breeding —According to Dr. Fulton the female turbot is
more numerous than the male, in the proportion of 197 to 100,
and larger on the average in the proportion of 118 to 100 by
length. The total number of eggs in the ovaries varied from
5,612,000 in a fish of 18 lbs. weight, to 10,114,000 in a fish weigh-
ing 21 lbs. Buckland calculated the number of eggs in a turbot
weighing 23 lbs. as 14,311,000.

According to Dr. Fulton’s results, turbot spawn on the east
coast of Scotland in April, May, June, and July. Mr. Holt’s
observations, at Grimsby, gave the same result, but extended
the period for a small proportion of fish to August and the
commencement of September. The spawning period is thus
prolonged. On the west coast of Ireland the observations were
not extensive, but spawning was taking place in April, May,
and June.

The eggs of the turbot when alive and fertilised measure
101 mm. in diameter (,); inch), almost exactly the same size
as those of the flounder. But they differ from these in having

262 MARKETABLE BRITISH MARINE FISHES

a single oil globule in the yolk, and this has a pale ochre
colour. The egg-membrane is close to the yolk, as in most
buoyant eggs. It was found that a few days after fertilisation
the eggs sank to the bottom
of the jar, although they were
studied on board a fishing vessel
in the open North Sea, so that
the later development takes
place nearer the bottom than
the surface of the sea.

The larvee were hatched out
seven to nine days after fertili-
sation. They were small, mea-
suring only 2°14 mm. in length
(a little more than ;4, inch),
Fic. 120.—Egg of the Turbot, alive and the tail portion is a good

and magnified ; after McIntosh. deal shorter than the yolk-sac
(Fig. 121). Neither mouth nor

anus is formed, the fin-membrane is narrow, and generally
the larva is less developed than -that of the plaice or
flounder when first hatched. The coloured pigment specks
by reflected light are a red-orange, and when seen by the

Frc. 121.—Larva of Turbot newly-hatched ; after Holt.

light passing through are much the same but more inclined
to crimson. None of the larve lived more than a few
days after hatching, but a good series of older stages was
obtained by Mr. Holt from the North Sea, by means of the tow-

THE FLAT-FISH FAMILY 263

net worked at the surface, in July. These specimens range in
lengthe@from. 3°42 mm. to 16:25 mm. (a little more than 12,
to 35,35 inch).

The smallest of these larva (Fig. 122) is still equal-sided : the

Fic. 122.—Larva of Turbot, a little more than § inch long, froma preserved specimen ;
after Holt.

head is relatively large, the tail fin is forming, but the marginal
fins are very narrow and without fin-rays. The jaws are fully
formed, and the mouth is very wide: the hinder end of the body
narrows rapidly. All the stages possess an air-bladder. At 5°42

Fic. 123.—Larva of Turbot, a little more than + inch long, with spines on the heap,
from a preserved specimen ; after Holt.

mm. (a little more than } inch), the development is much more ad-
vanced (Fig. 123). The body has increased greatly in breadth, the
tail-fin and marginal fins are well developed and provided with
complete bony fin-rays. The eyes however are still nearly opposite
to one another, the right being only a little higher than the left.

264 MARKETABLE BRITISH MARINE FISHES

The pigment in these specimens is dark, the black specks are
very abundant and evenly distributed, so that no spots or bands
are visible ; this distinguishes the turbot from the corresponding
stages of the brill. Another remarkable peculiarity is that in
the stages from that of 5'42 mm. in length to that in which the
transformation is nearly complete the head is provided with a
large number of spines, no trace of which remains in the full-
grown fish. There is a row of these spines above the eye, a few
at the hinder part of the lower jaw, and two strong rows on the
gill-cover. The spines are most developed in specimens I0 or II
mm. long (2 inch), and after that gradually disappear. At 13°5
mm. in length (just over 4 inch) the right eye is just beginning
to show beyond the edge of the head when the specimen is
placed on its right side. In the largest specimen, 16 mm. long,
i> inch) half of the right eye is visible from the left side.
These specimens were captured off the Horn Reef light
vessel, near the coast of Denmark, on the Great Fisher Bank, and
off the north-west corner of the Dogger. Itis a curious fact that
while they were brought to Grimsby from distances between
60 and 220 miles in the North Sea, numbers of specimens in
the older stages come, of their own accord, almost to the doors
of the Plymouth Laboratory. They are brought in with the
flood tide to Sutton Pool, and, swimming as they do at the very
surface of the water, are dipped up by boys in rusty tins
and brought to the Laboratory for sale. The sizes of such
specimens are commonly from 15 to 25 mm. (,%, to 1 inch), but
recently a series of the younger stages described by Mr. Holt were
obtained in the same manner. Fig. 124 represents a specimen
4 inch long. There are several interesting and remarkable
features about these young forms. The transition stages of other
flat-fishes have been obtained near the bottom; those of the
flounder, plaice, and dab, have no air-bladder, and when their
habits are noticed it is seen that they swim up from the bottom
by active exertion of the fins and fall when not moving. The
sole has an air-bladder in the transformation period, but has not
been taken at the surface in the open water. But the young
turbot float, or soar, in the water with no exertion at all, using
their fins gently now and then to move deliberately and rather
slowly in one direction or another. They can also in a tank lie
at the bottom, and although found at the surface, seem to be able

THE FUAT-FISH FAMILY 265

to sink or rise as they please. They are not easily alarmed,
and when one tries to catch them, seldom attempt to escape, so
that they can be dipped up with a small vessel or the hand with
the greatest ease. Other flat-fishes in these stages are very
transparent, and therefore not easy to see in the water, but the
turbot and brill are opaque from a very early stage, from the
very commencement of the development of the fin-rays and
bones. The large size reached by these fish before the trans-

Fic. 124.—Transition stage of Turbot, + inch long, from a preserved specimen ; after
C. G. Joh. Petersen.

formation is complete is also remarkable, the turbot being some-
times over an inch long before they remain on the bottom and
acquire the complete form and habits of the adult. It must not
be supposed that these fish in the process of transformation
swim upright like a fish whose two sides are alike. So long as
they are equal-sided, that is up to a length of about } inch,
while the eyes are opposite to one another they do swim in that
position, but as the right eye begins to rotate the body is held in
a correspondingly slanting position, and when the eye reaches the
edge or upper (left) side of the head they swim with the body

266 MARKETABLE BRITISH MARINE FISHES

horizontal, in the same position, or nearly, as when lying on
the bottom.

The advantage of this power and habit of swimming at the
surface is not difficult to discover. Even at these early stages
the turbot and brill are rapacious and feed on other fishes smaller
than themselves. They might capture such prey when lying
like the adult at the bottom, but in summer time the young of
other kinds of fishes are much more plentiful in the open water
and near the surface than at the bottom. In the aquarium at
Plymouth the young turbot have been fed on pieces of dead fish,
but both they and the brill much prefer living prey, and when
kept with other young fish, such as flounders, speedily devour
them, or choke themselves in the attempt.

After completing their transformation, losing the air-bladder,
and assuming the habits of the adult fish, young turbot have
only been found in very shallow water, near the margin of the
sea. At St. Andrews they have been taken with a seine net in
September and October, at a length of 2 inches. These are
doubtless the young hatched the previous summer. At Clee-
thorpes, from April to June, specimens from 3 inches to 4}
inches long are taken in small numbers in the shove-nets of the
shrimpers. These are only the smallest of the brood of the
preceding year, the majority of turbot a year old being larger.
The limiting sizes of mature and immature turbot observed at
Grimsby were for females 14 inches and 19 inches, for males
12 inches and 15 inches. As in other cases, these limits give the
sizes attained by some specimens at two years of age, while the
size of the smallest mature male may be taken as the greatest
size reached by the female at the end of the first year. On the
eastern grounds of the North Sea small turbot are taken in
considerable numbers, together usually with a proportion of
adults. The total catch on one voyage of a steam trawler on
these grounds in June was 140 specimens, ranging in size from
11 to 15 inches. Judging from the size,some of these may have
been mature. Ina single haul of the trawl at 10 to 12 fathoms,
about twenty miles from the Amrum Light, north of Heligoland,
also in June, there were taken two mature female turbots 147
inches and 24 inches long, nine immature females 134 inches to
154 inches, and twelve mature males 13 inches to 16 inches.
There can be no doubt that the year-old turbot, mostly from

THE PLAT-hIsh FAMILY 267.

4 to 8 or 9 inches long, live chiefly in the shallower water close
to the shore, and that the sample just mentioned included fish of
two years of age and upwards. It will be noticed that mature
turbot, some even of large size, are by no means entirely absent
from the eastern grounds at twelve fathoms.

The Brill (Rombus levis).

Distinguishing Characters——RKesembles the turbot in shape of
body, thickness and firmness of flesh, toughness and deep colour
of skin ; but it is narrower in proportion to its length and more
regularly oval. It has small smooth (cycloid) scales all over
both sides, but they project slightly from the skin ; no tubercles.
The fin-rays are more numerous than in the turbot, dorsal
76-85, ventral 53-63. The dorsal commences in front of the
upper eye, and its first ray is much branched. Colour in the
dead fish dark and uniform ; in life variable and speckled: lower
side white.

Szze-—The largest female recorded by Dr. Fulton was 26 inches
long, largest male 23 inches. They are commonly seen in the
market from 13 to 20 inches long.

Hlabitat—There seems to be no difference in this respect
between the brill and the turbot. The former is found through-
out the Mediterranean, and all round the British Isles, becoming
rare in the Orkneys and Shetlands. Like the turbot it is rarely
taken at depths greater than 40 fathoms, and occurs on sandy,
gravelly, or muddy ground. In the North Sea it is taken on
the Lincolnshire coast, the neighbourhood of the Dogger Bank
and Silver Pit, and off the Dutch and German coasts; but
northwards about the Great Fisher Bank, at depths over 4o
fathoms, neither turbot nor brill are often taken.

Mature brill, though often to be found in shallow bays, do
not usually enter estuaries, but the younger stages are often
found in the more seaward parts of the latter.

food.—As in the case of the turbot the food consists almost
entirely of other fishes. Ninety-four specimens were examined
during the Irish Survey, and in only three cases was anything
else observed; in two of these cases the food was squid, in the
third a shrimp. ‘The fish found was in nearly all cases sand-eels,

268 MARKETABLE BRITISH MARINE FISHES

occasionally sprats were present, and a dragonet and solenette
occurred each once. On the south coast, judging from observa-
tions made in the Plymouth Laboratory in February, the smaller
members of the cod tribe are the chief victims, namely the poor
cod and pout, or bib (Gadus minutus and G. luscits).

Lreeding—Dr. Fulton found that the females were more
numerous than the males in the proportion of 145 to 100, and
larger in the proportion of 123 to 100. The total number of
Ova in one specimen weighing 54 lbs. was found on calculation to
be 825,000. Spawning was found to be taking place off the east
coast of Scotland in April, May and June, and a few were stated
to be ripe in March. According to Mr. Holt’s observations at
Grimsby, ripe fish were first seen in the latter part of April, were
abundant in May and June, and none were seen after the end of
July. In the neighbourhood of Plymouth spawning takes place
chiefly in April, May, and June; and during the same months on
the west of Ireland.

The Eggs and thetr Development.—The eggs of the brill were
procured from ripe fish both on the east coast of Scotland and
on the west of Ireland, but they were hybridised in fertilisation,
in one case the milt of a turbot being used, in the other that of a
dab. In the former case the eggs developed healthily and hatched ;
in the latter, as might be expected, they died before hatching. li
1892, however, eggs were obtained at St. Andrews fertilised from
the male of the same species. They are buoyant eggs, with a
single oil globule, like those of the turbot, but larger, measuring
1°33 mm. in diameter. The oil globules are slightly coloured,
giving a number of living eggs together a pale inky tint. The
embryo in the egg after some days’ development is remarkable
for the Snares of pigment on the surface of the yolk sac,
and on the head and body : there are numerous black star-shaped
specks, and spots of yellow colour.

Unfortunately the early larval stages are not satisfactorily
known. We have a figure by Raffaele! of a larva hatched at
Naples from eggs taken from the sea and identified as those of
the brill. The identification is doubtless correct, and the larva
is characterised by the abundant pigment mentioned already,
now of a slightly darker chrome tint. It forms one distinct band
across the tail as in the larva of the flounder. The fin-membrane

1 Mitt. Zool, Station, Neapfel 8 Bd. 1 Heft, 1888.

THE BLAT-PISH FAMILY 269

extends on the back to the front of the head. McIntosh! has
figured a larva from the eggs fertilised with turbot milt, which is
closely similar, except that the oil globule is farther back in the

yolk.

Fic. 125.—Larva of Brill with two sides still similar ; after Raffaele.

a\fter this stage we have no observations until we reach stages
in which the fin-rays are formed, and the mouth and jaws well
developed. The earliest of these figured by Raffaele (Fig. 125) is

Fic. 126.—Larva of Brill with right eye nearly at the top of the head ; after Raffaele.

s inch long; it is still equal-sided. The pigment is abundant, and
forms distinct bands across the sides, five in number. The next
stage (Fig. 126) with the right eye nearly at the top of the head

1 Ninth Report Scottish Fishery Board.

270 MARKETABLE BRITISH MARINE FISHES

is +4 inch long and shows six bands. It is distinguished from
the turbot by these bands, by its narrower form, and by the
greater number of fin-rays. In the oldest stage figured by
Raffaele the transformation is practically finished, the two eyes
are on the left side, and the bands are breaking up into spots.
These specimens were obtained at the surface of the sea, in the
Bay of Naples.

Like the young turbot, the brill in the stages just described
are found with unfailing regularity and in considerable numbers
every year at Plymouth, at the surface of the fishing harbour,
Sutton Pool. They swim quite at the surface, having a large air-
bladder which enables them to support themselves in the water
without exertion, and they are carried by the flood-tide into the
harbour.

‘A number of these young brill were reared in the aquarium
at Plymouth. One of them was nearly 34 inches long in October
when about six months old, and four others were from 3 to nearly 4
inches in the same month. Two were kept till the following April,
and were no larger than those which were killed in October,namely,
between 3 and 4 inches in length. That these results are not
altogether unnatural is shown by their agreement with the con-
clusions to be drawn from the size of the young brill taken in the
shove-nets at Cleethorpes from April to July ; ten of these varied
in length from 3 to 54 inches, and must necessarily have been
hatched the preceding season.

The brill reaches maturity probably at a slightly smaller size
than the turbot ; the smallest ripe male in the North Sea was
10 inches long: of females the smallest mature was 13 inches,
the largest immature under 16 inches. As in the case of the
turbot both mature and immature are taken at about 12 fathoms,
to the north of Heligoland. The history of the young brill
agrees closely with that of young turbot, the yearling fish being
confined to the shallowest water near the shore, the older immature
with some mature being found between 10 and 20 fathoms ;
beyond 20 fathoms usually only mature fish occur.

THE FLAT-FISH FAMILY 271

The Megrim (Lepzdorhombus megastona),.

Distinguishing Characters.—This fish has a large mouth, large
head and large eyes, and a rather narrow, thin, pale body. The
teeth equally developed on the two sides, small, in two rows, also
on vomer. The eyes are on the left side as in turbot and brill.
The curve of the lateral line above the pectoral is somewhat
oblong, not semicircular. The skin is thin, and the scales
which are large and spinous (ctenoid), easily detached. The
dorsal fin commences in front of the upper eye, but the first rays
are not elongated or branched. ‘The fin-rays are more numerous
than in the brill, namely, dorsal 85-91, ventral 61-75. Colour, a
pale brownish yellow without distinct markings. Flesh rather
dry.

Szze—The largest recorded was 234 inches long: the largest
taken in the Irish Survey was 18 inches.

Names.—This fish is called by a different name at almost
every fishing port. At Plymouth it is always known to the
fishermen as the megrim, while the hawkers call it the lemon
sole. In Cornwall it is known as the whiff. Couch describes it
as the carter and the sail-fluke, supposing that there are two
separate kinds. In Cornwall it is also called lantern-fish, from
its transparency, as another species is called window-pane in
America. In Dublin it is called white sole, ox sole, and lemon
sole.

Hlabitat.—It is fairly abundant from the Bay of Biscay to
the north coast of Norway. Doubtful whether it exists in the
Mediterranean or whether its place there is taken by the allied
Speciess 54) Gosczz. lt occurs: on the ‘coast of Iceland. » Not
abundant in the North Sea.

This fish has a great range in depth. During the Irish Survey
specimens of 12 inches in length and upwards were taken at
various depths from 4 to 220 fathoms. They occurred in numbers
at 20 to 25 fathoms, at 50 to 60 fathoms, and at 154 fathoms.

It is evident that this fish is fairly abundant off the S.W. of
England, and on the western shores of Ireland and Scotland to the
Orkneys, and again further north, and yet is comparatively rare in
the North Sea and the Irish Sea. The probable explanation is
that in these latitudes it properly belongs to ground beyond the 50

272 MARKETABLE BRITISH MARINE FISHES

fathoms line, and only makes temporary migrations into shallower
water. In the works of Day and Couch are quoted stories of its
coming ashore in the Orkneys spontaneously, with its,tail erected
above the water to act as a sail; and the name sail-fluke is said
to be derived from this peculiar habit. Whether there is any
important fact concerning the habits of the fish at the base
of these stories is uncertain, but at any rate no one would
take them seriously without the evidence of some competent
observer.

food—According to the observations made in the Irish
Survey, the principal food, as in the case of the turbot and brill, is
fish, namely, sprats, sand-eels, whiting, gobies, &c. Crustaceans,
common shrimp and others, and squid, were found in one or two
specimens.

Lreeding—Dr. Fulton found that the females were both
larger and more numerous than the males, but as he only
examined twenty-one specimens, too much importance must not
be given to his figures. The proportions were in number
133 to 100, in length 131 to 100. On the west of Ireland the
numbers found were: males 43, females 160, or 372 females to
100 males.

On the west of Ireland these fishes were spawning in March,
April, and May. Spawning fish were only taken at 53, 154, and
200 fathoms, a fact which confirms the suggestion that the species
belongs properly to the deep water. Numbers of specimens
were taken in shallower water, but though some were mature
none were ripe. The number of ova in a female 18 inches long,
was found on calculation to be 440,000.

The eggs are like those of the turbot and brill, having a
simple yolk with a single oil-globule. In size they most resemble
those of the turbot, their breadth being 1°13 mm. (43> inch).
They have been examined both in the Irish Survey and at St.
Andrews. Hatching took place on the sixth and seventh days
after fertilisation. The larva was distinguished from those of
most other flat-fishes by the almost entire absence of coloured
pigment, the black specks being scattered equally over the
head, body, and fin-membrane, but not on the yolk sac. The
oil-globule is placed at the hinder end of the yolk, and the end
of the intestine is slightly separated from the yolk sac. When
the larve were four or five days old, the mouth became open

THE BLAT-FISH FAMILY 273

and yellow pigment had appeared. The later larval stages have
not been traced.

The next stage known is the youngest shown in small
specimens trawled during the Irish Survey at 80 fathoms, off the
Skelligs in August. The smallest of these was 19 mm. long (,55;
inch, or not quite #in). Its transformation is nearly but not quite
complete (Fig. 127). The right eye is on the left or upper side of
the head, and the front part of the dorsal fin has grown forward
to a point opposite the middle of that eye. The pigment has
already disappeared from the blind side. The scales have not
yet appeared.

Specimens 30 mm. long (1 inches) are still more like the
adult, the posterior part of the body having grown broader.

VLEET

ia Py,

ty Yj,
LMG fy :

LE,
GAA

Fic. 127.—Young Megrim or Sail-fluke, not quite # inch long. From a preserved
specimen ; after Holt.

Scales are developed at the root of the tail, and extend forwards
along the lateral line, but are absent elsewhere. In specimens
50 mm. long (2 inches) the scales are developed all over the skin,
except the head, abdomen, and along the basis of the marginal
fins.

There cannot be much risk of error in considering these
specimens as the fruit of the preceding spawning season. If
spawned in April they would be four months old. Other speci-
mens were obtained during the Survey ranging in length from
56 mm. to 180 mm. (2 inches to 7+ inches). One series of these,
taken also in August, were from 75 mm. to 130 mm. in length
(3 to 54 inches). These were taken in Ballinskelligs Bay in

T

274. MARKETABLE BRITISH MARINE FISHES

shallower water, about 30 fathoms, and may be considered to be
in their second year.

In the Irish Survey the smallest mature male was found to
be 10 inches long, female 12 inches, while the minimum sizes of
fish actually ripe were 10} inches and 12 inches respectively. As
the minimum of the sfev¢ fish is not mentioned, the numbers
of specimens to which the above figures refer are 100 males,
34 females. No effort has yet been made to discover the
maximum size of immature specimens.

The Scaldfish or Scaldback (dA rnoglossus laterna).

Distinguishing Characters.—Vhis fish differs from the top-knots
in its less shortened form, and smaller mouth, which is scarcely
larger than in plaice or dabs. Its most striking peculiarity is
the delicacy of the skin, which has given it its common name.
Friction in the trawl always removes nearly all the skin, leaving
the flesh bare as though the fish had been scalded. The scales
are very thin, those of the upper side larger and having a row of
minute spines along the posterior edge ; those of the lower side
smaller, without spines. The fin-rays are numerous, 87 to IOI
in the dorsal, 64 to 78 in the ventral. The dorsal commences on
the snout. The teeth are small and in a single row. In the
males above 54 inches long the dorsal rays from the 2nd to the’
6th inclusive are much elongated, and likewise those of the pelvic
fin. This occurs to a slight extent in the females above the same
size, but is absent in both sexes below that size.

Names.—This fish is called the megrim by Couch, and
apparently this name is applied to it in Cornwall, not to the
Lepidorhombus megastoma, it is also called the lantern-fish ;
but scaldfish is the most convenient and appropriate name
for it.

Habitat—Mediterranean to Norway. Has been found on
the east coast of Ireland as well as on the west, and in the
Firth of Clyde; it is rare, if not very rare, off the east coast of
Scotland and in the North Sea.

Size-—The largest specimens (males) were 8 inches long,
taken near Plymouth. The food has not been ascertained.

Breeding. Spawning occurs in April and May, and perhaps

THE FPLEAT-FPISH FAMILY 275

June: it has not been carefully studied. A ripe male was found
in April on the west of Ireland.

The Eggs and their Development—RKaffaele reports that the
eges of Arnoglossus are like those of turbot and brill, having a
simple yolk and a single oil-globule, but smaller, measuring only
0°6 to 0'7 mm. across (;2é4, or little more, about 3, inch). The
larva of this species has not been traced.

The smallest specimen obtained in the Irish Survey (Fig. 128)
was 25 mm. (1 inch) long. Many scales were still in the skin,
and it was doubtless provided with them all over during life.
In the preserved specimen there was not much pigment, only
patches of black specks here and there. This specimen was

Fre. 128.—Young Scaldfish, 1 inch long. From a preserved specimen ; after Holt.

taken at 41 fathoms in August ; it may have been spawned the
same year. In Cawsand Bay, Plymouth, young specimens are
abundant. In October they were obtained of the length of 2°8 to
34 cm. (II to 14 inch) and probably four or five months old.
In February others were 4°5 to 6°3 cm. (1°8 to 2°5 inches), and
these would be eight or nine months old. Older specimens were
abundant from May to September, and ranged from 1’9 to 5°4
inches. The larger of these must have been two years old, the
smaller one year. In December forty-three specimens 5°8 to
8 inches were obtained from trawlers fishing from ten to twenty
miles from the coast: these were two or three years old and
upwards, and were sexually mature. In September thirteen
specimens only 3°15 to 4°7 inches were taken eight to ten miles
2

276 MARKETABLE BRITISH MARINE FISHES

south of the Eddystone, in 36 to 38 fathoms, so that the imma-
ture specimens are not confined to shallow water.

A ripe male has been seen only 44 inches long, the smallest
mature female may be a little larger. It is to be noted that the
males may be ripe before the elongation of the fin-rays takes
place, just as a man’s beard does not fully develop until long
after puberty.

The Top-knots (Zeugopterus punctatus, unimaculatus,
norvegicus ).

Distinguishing Characters.—A\ll\ have short faces, no free root
to the tails, and very long dorsal and ventral fins. The hinder
ends of these fins are continued on to the blind side beneath the
root of the tail. The dorsal commences on the snout in front of
the eyes, and the ventral and broad pelvic occupy the whole
ventral margin forward to the gill opening. The vent is very
far forward. The mouth is large, and the gape almost at right
angles to the length of the body. The scales are very spiny, and
the spines are long and project up from the surface of the skin
giving a rough hairy appearance.

The first kind, called browny or bastard brill by Devon and
Cornish fishermen, is the roughest of the three, and its ventral
fin is united with its two pelvic, the vent opening between the
latter. The lower side is rather smooth. Fin-rays, dorsal 87 to
IOI, ventral 69 to 8o.

The second kind has the first dorsal-ray Soneasen the
ventral is not united to the pelvic; there is a single dark spot
in the centre of the hinder part of the upper side ; the lower side
is rough.

The third kind is less shortened and less rough, the scales
being less spiny and not projecting so much. There is no
elongation of the first fin-ray of the dorsal, no fusion of the
ventral and pelvic fins, little roughness on the lower side.

Names.—The three kinds may be called respectively the
common top-knot, the one-spotted top-knot, and the Norwegian
top-knot.

Hlabitat.—The first and largest form extends from the Bay of
Biscay to the north coast of Europe, the second from the Mediter-

THE FLAT-FISH FAMILY 277,

ranean to the Shetlands, and the third from the English Channel
to Norway. The first and third are fairly common in the neigh-
bourhood of Plymouth, and in the estuary of the Clyde, and
punctatus has also been taken on the east coast of Britain and
east coast of Ireland. Norvegicus occurs on the west coast of
Ireland, and so also does unimaculatus. They are usually found
in sandy bays, and taken in shrimp trawls. But as they are
known, punctatus and unimaculatus at least, to have the power
and habit of clinging to the surface of rocks, and do not burrow
in soft ground, it is probable that they are much more abundant

ff

_——

9

Larva of the largest Top-knot, a little more than 3 inch long, from a
preserved specimen 3; after Holt.

FIG. 120.

Fic. 130.—Head of the specimen shown in
Fig. 129, viewed from the dorsal edge, and
showing the projecting spines in the region of
the ears ; after Holt.

than they seem to be, but for the most part escape capture.
They adhere to the surfaces of the slate or glass sides of aquaria
by a constant waving motion of the hinder parts of the marginal
fins, which pumps out the water from beneath the body, and so
causes a pressure on the outside. They remain stationary thus
for hours, and from their dark colour are difficult to distinguish
on a dark surface.

Breeding.—Ripe eggs were obtained from a specimen of
unimaculatus 5 inches long,in June, in Loch Fyne. They were
buoyant and resembled those of the turbot, but were smaller ;

278 MARKETABLE BRITISH MARINE FISHES

they were not fertilised, but measured ‘96 mm. in diameter when
preserved. The yolk is simple and transparent and contains a
small yellowish oil-globule.

A ripe specimen of the smallest species, xorvegicus, was
obtained at a depth of 25 fathoms, near the Eddystone, in
March, 1892. It was 34 inches long. The eggs were ‘9g mm. in
diameter (,°.8, inch) and contained a single oil-globule.

Certain remarkable larval and transforming specimens were
taken in the Irish Survey, off the coast of Donegal, at depths
between 14 and 22 fathoms, in May, 1891. They ranged in
length from 5:8 to 10°%6 mm. (from a little less than } inch to a
little more than 2 inch). The appearance of the largest specimen
as seen after being preserved in spirit, and then made transparent,
is shown in Fig. 129. The chief peculiarity is the presence of two
sharp long spines projecting outwards from the region of the
ear; these are not easily seen when the fish is seen from the
side, but their appearance when it is viewed from the edge is
seen in Fig. 130. Two specimens of this same larva were taken
at Plymouth in May, and brought alive to the laboratory ; they
were captured by hand in a tide-pool at the breakwater. From
the number of the fin-rays and appearance of a specimen in a
more advanced stage of transformation than that figured, there
can be little doubt that these specimens are the larve of the
largest top-knot, Zeugopterus punctatus. Other similar specimens
of smaller size and without the spines have been described, and
probably belong to the one-spotted top-knot.

PEE COD AMT:

LIKE the flat-fishes, all the kinds of fish in this family are
without spiny fin-rays, and generally speaking without spines or
bony armour ; they carry no weapons either for offence or de-
fence except their powerful jaws and teeth. The fin-rays are all
soft and flexible, and even the scales are but slightly developed,
being small, smooth, and thin, and usually easily detached from
the soft skin. The dorsal and ventral fins together extend along
a great part of the length of the fish; the tail fin is separate. In
some there are three dorsals and two ventrals, as in cod, haddock
and others ; in some there are two dorsals, a long one behind
and a short in front, and a single ventral, as in the ling and
hake ; in some there is only one long dorsal and one ventral, as
in the tusk. The pelvic fins are on the throat in front of the
pectoral or breast-fins. The eyes are large, and in many kinds
there are barbels on the lips or chin.

The fishes of this family belong more especially to the Arctic
and Antarctic regions and the temperate zones, but are almost
entirely absent in the tropics. They feed for the most part on
or near the bottom, and the majority of them abound in the
shallower waters less than 200 fathoms, although there are a few
deep-sea species belonging to the ocean abysses. The majority
feed in the day-time, hunting their prey by sight, and as they
are voracious, rapacious fish with large mouths, and haunt the
sea-bottom, they are taken by hook or trawl with equal success.
Their food is various, consisting both of other fishes and of the
lower marine animals, especially crustacea. One species, the
burbot, lives entirely in fresh water.

The following are the British kinds of the cod family with

their chief peculiarities :—

280

MARKETABLE BRITISH MARINE FISHES

I. Species with three dorsal fins and two ventral, body not
much elongated.

ie

Oo

SY

te

The Cod.—Grows to a large size: the upper jaw is the
larger, its outer row of teeth enlarged, and there is a
barbel on the chin. Colour, greenish yellow or olive, with
numerous small dark spots ; lateral line white.

. The Haddock.—Smaller, but similar, distinguished by

the absence of small spots, by a black blotch on the
shoulder, and a black lateral line. Barbel small.

. The Bib, Pout, or Whiting Pout.—Smaller, very deep

in the body, copper-coloured with broad upright dark
bands. Barbel present.

. The Poor-cod.—Smaller, not so deep in the body, vent

further back : brownish yellow on the back, without bands.
Barbel present.

. The Whiting.—No barbel. Sides silvery, a dark spot at

the root of the pectoral fin.

. The Coal-fish.— Differs from the preceding in having the

lower jaw longer than the upper: teeth in the upper jaw
of equal size. A small barbel. Colour dark slate-blue,
almost black on the back and sides ; lateral line white.

. The Pollack.—Like the preceding, but has no barbel,

and the lower jaw longer. Colour, a dull green.

. The Poutassou.—Outer row of teeth in both jaws en-

larged, second dorsal fin short ; body narrow, silvery ;
lower jaw slightly longer than the upper.

Species with two dorsal fins, the hinder long, the front

one short: one ventral fin.

g. The Ling.—A barbel on the chin. Body elongated,

scales minute, fins narrow, very flexible.

10. The Hake.—No barbel, scales larger, fins broader and

Ta

12

stiffer ; teeth larger.

. The Fork-beard.—A _ barbel on the chin. Pelvic fin
forms a long forked filament extending behind the vent.
. The Burbot.—Closely resembles the ling, but the body
is broader behind the head, and the scales are larger.
The fish is much smaller,

13. The Lesser Fork-beard or Tadpole fish.—First dorsal

fin very small, rudimentary. Head flattened and fleshy.

THE COD FAMILY 281

III. Species in which there is no separate first dorsal, but the
front part of the single dorsal is a narrow fringe kept vibrating
during life.

14. The Three-bearded Rockling.— Two barbels on the
upper lip, one on the chin. Marked in the full-grown
state with black or brown round spots.

15. The Four-bearded Rockling.

16. The Five-bearded Rockling.

IV. Species in which there is one long dorsal fin and one

long ventral.
17. The Torsk or Tusk.

Amongst these, those kinds which are provided with a single
barbel on the chin feed chiefly on the bottom, their habit being
to swim with their heads inclined to the ground, continually
feeling the latter with the barbel. These fish eat both fish and
lower animals, especially crustacea. The ling is an exception,
it has a long barbel but feeds almost entirely on active fish.
The explanation of this seems to be that the ling is a some-
what nocturnal fish which haunts rocky ground and conceals
itself in the clefts and holes of the rocks. Its habits pro-
bably resemble those of the conger and rocklings, and its barbel
is of use to it as a sensitive tentacle to feel its way about, and
not to find crustacea or other animals on the ground. Its
elongated shape corresponds to the habit of concealment. The
ling is not taken in the trawl so commonly and in such large
numbers as the cod is.

The habits of the rockling are known from observations on
specimens in confinement and on the shore. They are entirely
nocturnal and self-concealing fish, remaining under stones or in
crevices among rocks except when they perceive the neighbour-
hood of prey or food, the presence of which they recognise by
smell rather than sight. They use their barbels for feeling about
on the bottom when seeking their food.

Those fishes of this family which have no barbel feed more
on swimming creatures than on those that walk or crawl, and
the kinds that prey most largely on migratory fish which swim
near the surface are those which have a projecting lower jaw.
This is the case particularly in the pollack, to a less degree in the

282 MARKETABLE BRITISH MARINE FISHES

coal-fish, but the hake although its lower jaw scarcely projects at
all feeds chiefly on surface fish such as pilchard, herring and
sprat.

The eggs of the fishes of this family are all of the buoyant
kind, with the single exception of the burbot, whose eggs are shed
loose and separate at the bottom of the sluggish fresh-water
streams which it inhabits. Apart, however, from the fact that
they develop at the bottom of the water the eggs of the burbot
are quite similar to those of the rocklings, and these would also
sink in fresh water. There isa great similarity between the eggs
of the cod family and those of the flat-fish family. All the
members of the first group in the list given above (species of the
genus Gadus) have eggs in which the yolk is quite simple and
without oil globules: these eggs agree in these respects with those
of the small-mouthed flat-fishes, plaice, flounder, dab, &c. (species
of Pleuronectes). It is almost impossible to distinguish these
eges from one another at the early stages of development ; the
only differences among them are slight differences of size, and in
some cases even these are wanting. The remaining members of
the family all have eggs with a single oil globule, like those of
the left-sided flat-fishes, turbot, brill, &«. There are no eggs in
the cod family corresponding to those of the soles.

The larve are always distinguished by the fact that the hinder
end of the gut is situated at a distance from the edge of the fin-
membrane. The young in the third or adolescent period have
various habits. Those of the rocklings are entirely surface
swimmers, having for a time a bright silvery skin like that of the
sprat or herring. The young of other kinds are found near the
bottom or among the sea-weeds and rocks of the shore. The
very young stages of cod, haddock, &c., are often found lurking
under the broad swimming bells of large jelly-fishes which are
so abundant near the coasts in summer, but when they get a
little larger they abandon the surface of the open waters and seek
the shore and the bottom. The young of cod, whiting, pollack,
and coal-fish are all found near the shore in their first year,
and a little further out in their second, while those of the
haddock, hake, and ling are not found close to the shore, and
only exceptionally in moderately deep water ; these species are
reared in the deeper and more distant waters.

ee

THE COD FAMILY 283

The Cod (Gadus morrhua),.

Distinguishing Characters.—The body of the cod is thick and
rounded in front, the tail rapidly diminishing in thickness towards
its end. The ventral fin begins beneath the fourth or fifth ray of
the second dorsal, and the hinder edge of the tail-fin is straight
or very slightly curved inwards. The mouth is large, the angle
of the jaw being behind*the front edge of the eye. The cod
reaches and sometimes exceeds the length of 5 feet, and weighs
from 30 to 50 lbs.

FHlabitat—On the European coast from the Bay of Biscay
to the north of Norway, and on the American coast from Green-
land and Iceland to New York. It is not found abundantly
beyond a depth of 120 fathoms.

Dr. Fulton found that the females were more numerous than
the males, but not so large: the difference in length however was
not great. The proportions are 133 females to 100 males in
number, in length 95 to 100.

On the east coast of Scotland, according to the observations
of the Fishery Officers, ripe cod are found in every month from
January to June inclusive, but the numbers of individuals in this
condition are very small except in the three months, February,
March, and April, which form therefore the chief spawning period.
At the Lofoten Islands, Sars found the spawning taking place
chiefly in March and April.

The fish seem to approach the coast in order to shed their
spawn, at any rate in the Lofoten Islands, where the declivity of
the sea-bottom is very rapid. Off the Yorkshire coast in the
neighbourhood of Flamborough Head, twenty to forty miles out,
large numbers of spawning cod are taken by the trawlers in
February and March, and along the east coast of Scotland the
cod spawn within these distances and beyond.

The egg of the cod is like that of the plaice and flounder, &c.,
having a simple yolk without any oil globule, and only a small
space between the yolk and the egg-membrane. It is 1°39 mm.
(little more than 4, inch) in diameter, almost exactly the same
size as the egg of the lemon dab, from which it could scarcely
be distinguished in the earlier stages of development.

Development usually takes place naturally, on account of lati-

284 MARKETABLE BRITISH MARINE FISHES

tude and season, in cold water. At a temperature of 45° F. the
eggs hatched in twelve days at the Marine Station at Granton,
and in thirteen days at about the same temperature in the United
States, while at 38° they were not hatched till the 20th day.

The newly hatched larva is a little over 4 mm. in length
(4; inch). With other species nearly allied such as whiting,
haddock, it agrees in the fact that the gut ends behind the yolk
at some distance from the edge of the fin-membrane ; while it
differs from these other species in having four bands of black
pigment on the body, one at the region of the pectoral fins, one
at the hinder end of the yolk, two on the tail. There is no pig-
ment on the fin-membrane. In larve a little older the fin-mem-
brane instead of being flat throughout its length expands into a
wide bladder over the head: this disappears again at later stages.
Fig. 56, p. 103, shows the character of the larva when ten days old,
but the limit of the bladder over the head is not indicated.

Sars investigated the growth and development of the young
cod very carefully in the neighbourhood of the Lofoten Islands
in 1866 and 1867. In the former year he commenced his obser-
vations on May 7th, when he found that the spawning was
finished, and large numbers of fry were hatched. On May 20th
he was able on a calm day to see numbers of the fry near the
surface of the water ; they were about one-third of an inch in
length, and were very transparent. All that could be seen
distinctly from a boat was the comparatively broad head with
the eye projecting on each side, while the rest of the body
appeared like a fine thread vibrating constantly. These little
fry were feeding on very minute crustaceans, which swim near the
surface. On June 12th he had another opportunity of watching
the young cod fry in the sea. They were considerably larger,
measuring nearly an inch in length, and had to some extent
advanced from the larval or primitive condition to that of a
perfect fish. The primitive fin which runs unbroken round the
hinder end of the body had partly divided into the first two of
the fins on the back which are seen in the grown fish, and the
characteristic barbel on the chin had begun to show itself as a
little projection.

After this bad weather set in, and for some days Sars was
unable to make observations in the sea. On June 23rd he found
a few of the young cod, but the majority had disappeared. On

THE COD FAMILY 235

July 5th he made the discovery that the little fish were shelter-
ing themselves under large jelly-fishes which were very abundant,
and he caught numbers of them. He found that they practised
this habit for the sake of the crustacean parasites of the jelly-
fish, specimens of which he found in the stomachs of the fish.
The largest young cod which he caught at this time measured
1} inches in length and showed already distinct colours, five or
six dark streaks running round the body, while the sides showed
a silvery or golden gloss.

The next year, on August 3rd, Sars caught young cod-fish
swimming in shoals in one of the curious streaks which are
formed in the sea by currents, and in which floating weeds, jelly-
fishes, and other floating animals often collect in quantities.
These fish were about 2 inches in length, or a little more. The
fins of the perfect fish were fully developed in these, and also the
barbel under the chin, and apparently the scales. In colour
they were marked above with lines of square spots of a reddish-
brown, the sides being silvery and golden. At this stage then,
when the cod are only about 2 inches long, what I have called
the second stage of their life is over, and they have reached in
all important respects the condition of the perfect fish.

The cod at the Lofoten Islands spawns chiefly in March and
April, and these most advanced young were found at the very
beginning of August, so that they could not be more than five
months old. But even at the earlier stage, at the beginning of July,
when only 1} inches long, and found frequently sheltering under
the jelly-fishes, they have practically completed their transfor-
mation, and these were found only four months after the com-
mencement of the spawning period. It must be remembered,
however, that in the cold water of the Lofoten Islands cod eggs
take a long time to hatch. Sars found in vessels kept on shore
that the egg hatched in eighteen days, and in the sea the water
would be colder, so that we must take off about three weeks for
the period within the egg, and we arrive at the conclusion that
the little cod, 14 inches long, which had gone through their
transformation, were little more than three months old, if
spawned at the beginning of the spawning period, while if they
came from eggs shed in April they were not much more than two
months.

The development of the cod has been also studied by Professor

286 MARKETABLE BRITISH MARINE FISHES

McIntosh and Mr. Prince at St. Andrews. They were not able
to keep the larve alive in aquaria after the supply of yolk was
exhausted, but they succeeded in recognising the young forms
in various successive stages captured in the Bay. The smallest
of these were 5 mm. long (+ inch) and were taken on April 30th,
middle of May, and June 1st. The fin-membrane was still
entirely without fin-rays. Others were 6 mm. long. In those of
7mm. in length fine rays had appeared in the fin-membrane
behind ; the bars of colour on the tail had spread out and were
no longer distinct.

Taken with these were specimens somewhat larger and older,
8 to 10 mm. long or more. At the former length the larval
fin is still present and undivided, but at 10 mm. (2 inch) the
permanent fins are marked out and the rays have begun to
appear in them, while the original membrane between them is
disappearing. Up to this stage the little larvae had been feeding
on minute crustaceans (copepods), and these continue to form
their principal food.

Older specimens taken also on June Ist were 13 inch long,
and showed the fins more completely developed, and the com-
mencement of the barbel on the chin. The colour of these and
larger specimens up to 14 inches long consists of dark greenish-
brown bars irregularly arranged, separated by pale areas.
In June and July young cod from 12 to 1¢ inches in length
were found abundantly in St. Andrew’s Bay ; the speckled colour
is very characteristic.

Sars found that the young cod after July lived among
the sea-weeds on the rocks near shore. In October they
were 4 or 5 inches long, in December 6 to 8 inches. These
sea-weed cod were of a reddish-yellow colour with thick bodies,
and fed chiefly on crustaceans, while others which lived on
sandy ground, fed on worms and small fish and were light green
or grey, and thinner. During the following summer the year-old
cod remain among the weeds and near shore, and measure on an
average I2 inches in length. Towards autumn they go out to
deeper water, and Sars concludes that the size at which breeding
commences, namely about 3 feet in length, is not reached until
the fish are three years old.

The young of the cod were reared from the egg in Norway
by Dannevig at his well-known establishment at Arendal, but he

THE COD FAMILY 287

only recorded their length, and did not make a study of their
transformation. He put 500,000 fry, hatched on April 27th,
into an enclosed pond of sea water, and on July 12th they
measured a little more than 2 inches in length. At this length
they must have completed their transformation, and thus the
period required for this was two months and a half.

In October these cod measured 4% inches to 62 inches, and in
the following February 14 to 16 inches. Mr. Holt found that at
Grimsby the critical sizes of cod in reference to sexual maturity
were 22 to 35 inches ; none were mature at a length less than 22
inches, none immature at a length over 35. No difference in
this respect was found between males and females. The
evidence available indicates that the lowest limit is not reached
at one year of age, but it is probably reached by some individuals
at two years.

The Haddock (Gadus aeglefinus).

Distinguishing Characters—The barbel on the chin is very
short. The vent is further forward than in the cod, the first
ventral fin commencing below or very slightly behind the com-
mencement of the second dorsal. The body is narrower than
that of the cod. The black blotch on the side is beneath the
middle of the first dorsal fin. The sides and back in the fresh
fish have a beautiful bronze-coloured reflection ; the lateral line
is black. A specimen has been recorded which measured
37 inches in length, and weighed 24} lbs., but the largest of
a large number measured for the Scotch Fishery Board was
25 inches long.

Habitat—From the Arctic Ocean to the Bay of Biscay on
teteasterm™ snores of the Atlantic, to Cape Matteras on) the
western side. It is not abundant in the English Channel, though
said to be taken there in considerable numbers in certain years.
Very abundant in the North Sea, in the northern part of which
it forms the staple produce of the trawl fishery. More abundant
on the north, east, and west coasts of Ireland than on the south.

Food.—The principal food in the Firth of Forth was found to
be crustaceans and molluscs ; the former were found in 60 per
cent. of the stomachs, the latter in 40 per cent. Echinoderms

288 MARKETABLE BRITISH MARINE FISHES

and worms were of nearly equal importance, 29 per cent. of the
stomachs containing the former, 23 per cent. the latter. Fish
remains were found only in 5 per cent. Of the crustaceans
taken the most numerous were common shrimps, and next in
frequency were hermit-crabs, swimming crabs, and sand-hoppers.
Among the molluscs, common bivalves and the razor shell were
most abundant ; the whelk and other univalves, octopus and a
kind of small cuttle-fish also occurred. Of the marine worms the
sea-mouse (Aphrodite) was the most numerous.

On the west coast of Ireland echinoderms occurred most
frequently in haddocks’ stomachs, crustaceans next, worms next,
and molluscs last.

The females are nearly twice as numerous as the males, the
proportion being 188 to 100, but the males are slightly larger, in
the proportion of 100 to 98. The haddock, like the cod, spawns
on the east coast of Scotland in February, March, and April.
The spawning fish are found from five miles off the coast upwards,
and at depths of 20 fathoms and upwards. On the west coast
of Ireland ripe fish were taken at 38 fathoms, 44 fathoms,
80 fathoms, and 154 fathoms, but the mature fish approach
nearer the coast in the spawning season. ~

The eggs closely resemble those of the cod, the only differ-
ence being that they are larger, I-45 to 1°5 mm. in diameter
(;85 inch) ; they are thus somewhat smaller than those of the
plaice.

The larva when first hatched is a little larger than that of
the cod, which it closely resembles. As in the cod only black
pigment is visible, and the haddock larva can be distinguished
by the fact that the pigment does not form bars across the body,
but is confined in the tail to the ventral edge; it is absent from
the fin-membrane and from the yolk-sac.

No careful study of the later larval stages of the haddock
has been made. Professor Sars mentions that he could dis-
tinguish the little haddock by their shorter and stouter form,
and they have been found at a length of 2? inches, lurking under
large jelly-fishes like the cod. In Dr. Fulton’s fine-meshed
trawl seven specimens, 1 inch long or less, were taken in one
haul in the Moray Firth in July, fifteen miles from the shore at a
depth of 30 fathoms, 339 specimens 2 to 5 inches long were
taken, the great majority at depths between 20 and 30 fathoms,

THE COD FAMILY 289

and from four to ten miles from the coast. Nearly all these were
captured in September, and were doubtless the young of the
year ; they occurred off the entrance of the Firth of Forth. In
February, March, and April, specimens 6 to 10 inches in length
were taken, but not in large numbers. These are the year-old
fish. Dr. Fulton thought that probably the young haddock
frequented rocky ground and so did not come much in the way
of the trawl.

Mr. Holt’s observations in the North Sea tend to confirm the
result of Dr. Fulton’s, that the young of the haddock frequent
erounds at some distance from the coast. In 1892 he obtained
specimens a few months old on three occasions, once in July,

. Bec usseeee.
Rae a ess ar gy Se
SO Lh
92 Bhp AE Mok ote

Fic. 131.—Larva of Haddock, just after hatching.

twice in August. On the first occasion two specimens were
taken, 2} to 34 inches long, at 30 fathoms on the inner shoal of
the Great Fisher Bank amongst the sea-mat (/V/ustra foliacea),
which was brought up by the trawl. As this was a deep-sea
fishing trawl of large mesh there may have been a very large
shoal of these young haddocks on that ground, the two taken
having been only accidentally entangled in the “weed.” In
August thirty-nine specimens altogether were obtained, 3,%, to
5 inches long, captured fifty-four to sixty-one miles east of Spurn
Light Vessel at 16 to 20 fathoms. No specimens were taken by
the inshore fishermen in the Humber.

The investigation of the limit in size between maturity and
immaturity has not been so thorough in the case of the haddock

U

290 MARKETABLE BRITISH MARINE FISHES

<

as in others, but both sexes seem to be often mature at I1 or
12 inches, while some females were immature at 16 inches. We
may consider 11 to 16 inches about the length reached at two
years of age.

According to Mr. Holt’s experience, when the fish of the
year are taken, less than 5 or 6 inches in length, no large fish
are captured, and he believes that the haddock swims in shoals,
the older fish separate from the younger. The smaller fish in
the catches made by the trawlers are 10 to 13 inches long, and
the proportion of these was noticed to decrease in summer and
increase in autumn and winter. Mr. Holt suggests that the
reason of this is that the shoals of full-grown or large fish are
recruited at this season of the year from the small fish which
have grown large enough. But it seems that the recruits must
be at the end of their second year, as very few if any probably
reach 10 inches at the end of their first year.

Whiting (Gadus merlangus).

Distinguishing Characters—No barbel on the chin; the
black spot is above and about the root of the breast fin. The
vent is further forward than in the cod or haddock, the first
ventral fin commencing beneath the middle of the first dorsal.
The tail-fin ends with a straight or very slightly incurved edge.
The largest whiting recorded by Dr. Fulton was 21 inches long ;
the weight of large fish is usually from 3 to 4 lbs.

Habitat.— From Norway to the Mediterranean. More
abundant and larger off the south coast of England than in
the North Sea, but occurring in numbers round all the coasts of
Britain and Ireland. On the west coast of Ireland it was not
taken at a greater depth than 40 fathoms, and it is restricted to
the neighbourhood of the land more than cod or haddock.

Food.—F¥ive hundred and thirty-nine stomachs containing
food, from whiting taken in the Firth of Forth, were examined.
The pringipal food was fish and crustacea, 65 per cent. of the
stomachscontaining the former, 37 per cent. the latter. Of
the erustacea, only the common shrimp and the red shrimp
oceurred abundantly; of the fish, herrings and other whiting

‘

a

THE COD FAMILY 291

were most frequent. The whiting is thus strongly addicted to
cannibalism.

The excess in number of the female sex is a little greater in
the whiting than in the haddock, namely, 211 to 100 ; the females
are slightly larger, but the difference is not important, the
average length of females to that of males being as 104 to 100.

On the east coast of Scotland the whiting spawns a little
later than the haddock and cod, the months being March, April,
May, and June. On the west coast of Ireland, March and
April were the principal months, and near Plymouth spawning
begins in February. The ripe fish are found at no great
distance from the shore and at no great depth, from two or
three miles upwards, and from 10 fathoms upwards.

The eggs resemble those of cod, haddock, &c., but are
smaller than those of the cod, measuring 1°07 to 1°25 mm. in

ue a
ea
ag i oF

ary . =
me
au Avnanaanne?
= eT Ce ES
Gc See eS (SLR OS

Fic. 132.—Larva of Whiting after absorption of the yolk, from a specimen hatched
in the aquarium ; after Prince.

diameter. The fish spawn every year in the Plymouth Aquarium
and the eggs are hatched without difficulty.

The larva when first hatched is 36 mm. long, a little smaller
than that of the cod. It has been hatched from eggs taken
from the fish both at St. Andrews and at Plymouth. As in cod
and haddock the black pigment is confined to the body of the
larva, but in the whiting there are yellow pigment-specks on the
yolk-sac and fin-membrane. The recognition of the eggs and
larve of these different fish, cod, haddock, whiting, &c., when
taken from the sea is a matter of some doubt and difficulty,
because of the close similarity. The larve have been reared in
confinement for some days after the yolk was absorbed. There
is a large distension of the skin over the head, as in the cod.
The black pigment-specks at these stages extend without a

break along the upper and lower edges of the body.
Us 2

292 MARKETABLE BRITISH MARINE FISHES

According to McIntosh and Prince the young whiting taken
in St. Andrew's Bay can be recognised from the length of
15 mm. (2% inch) upwards; they are distinguished from young
cod by the more abundant pigment and the much greater
extent of the first ventral fin, already formed at that size.
At lengths from 4 to 1+ inches, a small but distinct barbel
is present, although it is absent in the adult whiting: it is
much shorter than in cod of the same length, and disappears at
a length of about 3 or 4 inches.

The young whiting of the year are found in great abundance
close to the shore, and in bays and estuaries. In fact they are
like the plaice in this respect, and get in the way of shrimp nets
and inshore fishing everywhere in hundreds and thousands. In
the course of Dr. Fulton’s special search for small fish with a
fine-meshed trawl, whiting were far the most abundant of the
young fish captured ; over 26,000 were taken as compared with
only about 1,000 young plaice. The region of the young
whiting, however, is rather farther from the shore and in greater
depth of water than that of the young plaice. In Dr. Fulton’s
investigation in 1889, an immense shoal of young whiting were
found in the Firth of Forth, extending from Inchkeith to some
eight miles east of the Isle of May, over 3,000 specimens being
sometimes taken in one haul of the trawl. Nearly all these
fish were from 2 to 5 inches in length, in September, and must
have been four to six months old. At the mouth of the
Humber, at the beginning of September, 254 whiting 2? to 5
inches long were taken in the shrimp trawl. In the shrimp
fishing of the Lancashire coast also large numbers of young
whiting are taken, the largest hauls in July and August. At
Plymouth, although full-grown whiting are very abundant, I
have not ascertained where the young of the year are most
plentiful: I have taken them in the trawl in Whitsand Bay at
3 to 5 fathoms, and in a midwater net just outside the Eddy-
stone: these were specimens 2 to 34 inches long taken in June
and July.

It is not surprising that young whiting should be taken by
shrimpers, since they are engaged largely in feeding on the
shrimps and other small crustacea. In Lancashire Professor
Herdman found in 116 cases of recognisable food among whit-
ing 3 inches long and upwards, that crustacea occurred in 73 per

THE COD FAMILY 293

cent., fish, namely sprats and sand eels, in 24 per cent., while
other kinds of food were unimportant.

The young whiting are scarcer in shallow waters in winter ;
they pass out on to deeper grounds with the cold weather.
Fulton found that in February, March, and April the majority
were 5 or 6 inches long, which may be taken as the length at
one year of age.

The smallest mature whiting on the east of Scotland were
9 inches long in both sexes, and this length is doubtless reached
by many at two years of age.

The Coal-fish (Gadus virens).

Distinguishing Characters —The lower jaw is only slightly
longer than the upper, the barbelis rudimentary. The first ventral
fin commences beneath the last rays of the first dorsal, and ends
below the end of the second dorsal. The body is not much com-
pressed and not very deep from the back to the belly, but rather
slender. The colour on the back is dark, almost black, the
lateral line white. It grows occasionally to 43 inches long, the
usual length being between 2 and 3 feet.

Habitat.—From the Arctic Ocean to the Mediterranean. In
the British Islands more abundant on the more northern coasts,
very plentiful in the Orkneys and Shetlands and on the east coast
of Scotland. It extends to 70 fathoms.

Names.—This fish in its younger stages being very abund-
ant and familiar on the coasts of Scotland and Ireland, has an
extraordinary variety of local names. Green-cod, saithe, and
sillock are the most commonly used; in Yorkshire the young
are called blue-backs.

Lreeding—It spawns in February, March, and April, but not
being taken in large numbers in the trawl, and ripe specimens
not being usually taken on lines, the spawn has not been so easy
to obtain as that of other species. The fertilised eggs have how-
ever been examined in the living condition at St. Andrews.
They are similar in character to the eggs of the cod, but smaller,
being only 1:02 mm. in breadth, or scarcely more than 5}; inch.
The hatched larva was much like that of the cod.

The larve and transformation stages are to be found near the

2904 MARKETABLE BRITISH MARINE FISHES

surface of the sea, but have not been traced. The young from
I inch in length upwards are well known: in their first summer
they swarm around rocky weed-covered shores, and are seen in
numbers about the piers of harbours. At the same time larger
specimens about a year old are seen and casily caught with hooks
in harbours and up to a certain distance from the shore. The
limits of size of the year-old fish have not been definitely ascer-
tained, but many of them are only from 4 to 7 inches long. The
size at which spawning commences is also uncertain.

Thus there is no doubt that the young of this fish live near
the shore, while the adults roam far out to sea and to consider-
able depths. In the Irish Survey 164 specimens under 4 inches
in length were taken, all at depths less than 5 fathoms, while
43 adults over 30 inches in length were taken at 70 fathoms.
As in the case of other species, the young live principally
on the small crustacea which abound among the sea-weeds or on
the bottom, while the older fish feed principally on other fishes,
in the North Sea especially on the herring. In the young fish
the upper jaw is longer, and the barbel is well developed, but
beyond a length of about 12 inches the lower jaw becomes the
longer and the barbel a mere rudiment, a change which corre-
sponds to the change of habits and food.

The Pollack (Gadus pollachius).

Distinguishing Characters—Lower jaw longer than in the
coal-fish, no barbel, body deeper, and the colour green instead of
blue or nearly black. It grows to 3 feet in length or more, but
is usually seen between 18 inches and 30 inches.

Hlabitat.—F rom Norway to the Mediterranean ; in the British
Isles commonest on the south coast, especially off the shores of
Devon and Cornwall. It has not been taken at depths greater
than 40 fathoms.

food.—In the Irish Survey the larger pollacks were found to
have only other fishes in their stomachs, namely sand eels, sprats,
scald-fish, girnard, and others. The younger specimens con-
tained crustaceans, worms, and molluscs.

Breeding.—On the west of Ireland pollack were found to be
ripe in April and May. In Shetland ripe fish were obtained in

THE COD FAMILY 295

May, but on the coast of Cornwall spawning appears to com-
mence in March, or perhaps in February, the young of the year
being found at the beginning of April. The eggs were examined
in the Irish Survey, and found to be buoyant and like those of
the cod, haddock, and whiting, resembling the latter closely in
size. The eggs were not hatched.

In Cornwall I have seen the young pollack in numbers only
qo to I inch in length in April, and estimated their age at about
six weeks. In October I have taken a number in Cawsand Bay,
34 to 42 inches long, and have no doubt these were hatched in the
preceding spring. The pollack caught in Plymouth Sound in
June and July are 12 to 15 inches long, and are probably in their
third year, but as the size at which maturity commences has not
yet been ascertained, it is difficult to estimate the later growth.

In the Irish Survey all young pollack under 10 inches were
taken at depths less than 5 fathoms. Pollack, whether young or
adult, are almost always found in the neighbourhood of weed-
covered rocks.

The Ling (Molva vulgaris).

Distinguishing Characters—Several large teeth in the lower
jaw and palate. The barbel is nearly as long as the lower jaw.
The ventral fin commences beneath the seventh or eighth ray of
the second dorsal. The tail fin has a rounded edge. The dorsal,
ventral, and tail fins, are darker towards the margin, but edged
with white. Usually the back is a uniform grey, and the belly
light, but some specimens have large rounded black spots on the
back and sides. The ling is said sometimes to reach 7 feet in
length, its usual length is from 4 to 6 feet.

Habitat—From Spitzbergen to the Straits of Gibraltar, on
the east, and Newfoundland on the west. It is abundant all
round the British and Irish coasts, but most plentiful in the
northern parts of the North Sea, about the Orkneys and Shet-
lands, and the Faroe Islands. On the west coast of Ireland,
mature ling were taken in summer at various depths between 5
fathoms and 150, but the greatest number between 30 and 60
fathoms.

Food.—The ling appears to feed almost entirely on other fish.

206 MARKETABLE BRITISH MARINE FISHES

Forty-one stomachs containing food were examined in the Irish
Survey, and fish were found in thirty-three : mackerel in six, flat-
fish (megrim and dab) in three, gurnard and haddock each in two,
scad and Norway pout in one. A Norway lobster was found
in one, and cuttle-fishes and a kind of octopus (/edone) in eight.

Lreeding—The proportion of the sexes in size has not been
ascertained, but in number they appear to be very nearly equal.

According to the records of the Fishery Officers in Scotland,
the ling spawns in April, May, June, and July, principally in the
latter three months.

The egg is 1°08 mm. in diameter (,); inch), and has a single
large oil globule with a pale green colour. Eggs aetienlle
fertilised at sea were hatched at St. Andrews. ThE! larvee hatched
out on the ninth day. They were about 3 mm. (3; inch) long,

LD
te ee , nee

Mi TE =e
I as

Fic. 133.—Newly hatched larva of the Ling, alive and magnified ; after McIntosh.

and were very delicate and transparent. A peculiarity about
them is that the head and aie are much bent down over the
front of the yolk (Fig. 13 There are black pigment specks
on the body, and sae callers specks on the yolk-sac and
marginal fin-membrane.

When a week old the larva measures 3°3 mm. (443, inch), and
has a pretty and characteristic appearance under the microscope
(Fig. 134). The yolk is not quite all absorbed: the black pigment, in
the form of rather large stars, extends along the edge of the back
and ventrally, and towards the tail extends into the fin-mem-
brane, while the greenish-yellow specks are very numerous. The
mouth is open, but the jaws not developed.

The intermediate stages of the ling are remarkable for the
elongated throat fins, which reach back behind the vent. In colour
the fish in these stages are greenish on the back, and as soon as the

RHE, COD) FAMILY 297

fin-rays appear they can be recognised by the arrangement of the
fins. Specimens in these stages, 2 inch, 2 inch, and # inch long,
were taken off the Isle of May (Fig. 135) in July and August.
They were captured in a large tow-net in mid-water, or not far
from the surface, and it appears from this that for about the first
two months of its life the young ling resembles in its habits the

FIG. 134.

Larva of Ling thirteen days old, alive and magnified ; after Prince.

young of the rocklings. The next stage seen was that of a
specimen 34 inches long, stranded on the shore in December.
In this, the chief peculiarity was that the colour was in stripes
along the body, an olive-brown band passing along the side, a
white band above this, and a narrow line of dull orange along the
middle of the back. The barbel was long. The history of the
ling after this stage is not well known. Specimens from 7? to 12

Fic. 135.—Transformation stage of the Ling, + inch long ; after Prince.

°o

inches long occur not uncommonly off the mouth of the harbour
at St. Andrews, and are caught by line fishermen in the neigh-
bourhood. At this stage the stripes are broken up into large
irregular blotches. These small fish occur in summer, and are
about a year old. During the Irish Survey, of 203 ling caught
only six were under 24 inches in length, and these occurred at

298 MARKETABLE BRITISH MARINE FISHES

depths between 16 and 55 fathoms, as many in the deeper as the
shallower water. The size at which it becomes sexually mature
has not been ascertained: a female, 30 inches long, has been
found to be half ripe.

The Hake (Merluccius vulgaris).

Distinguishing Characters——Mouth large, teeth pointed, in
two rows in the jaws, and present also on the palate. The first
dorsal fin somewhat triangular, higher than the second. The
hinder portion of the second dorsal and ventral fins broader
than the rest. The ventral fin commences beneath the third
or fourth ray of the second dorsal. Dark grey along the back,
lighter on sides and belly: inner surface of mouth and gill
cavities black. It grows to 4 feet in length, but the more usual
Size 41S 2 Of, 2 fect

Habitat—From Norway to Maderia and throughout the
Mediterranean, and also on the American coast as far south as
Cape Hatteras. It is more abundant on the south coast of
England and Ireland than on the other coasts of the British
Isles. It is not caught on the east coast of England and the
neighbouring parts of the North Sea, but is plentiful in the
Skagerack and on the west coast of Denmark in May and
June. It is a deep water fish, having been taken at depths up
to 400 fathoms ; and it is also oceanic, only approaching the coast
occasionally. It appears to be true of the more oceanic
migratory fish generally, as of hake and mackerel, that they
are found in abundance off the south-west of England, the
western shores of Ireland and Scotland, and the coast of Norway
and northern parts of the North Sea, but penetrate less com-
monly into the shallower enclosed waters of the Irish Sea and
southern part of the North Sea. Their visits to these enclosed
seas take place in summer, and they are not found there in
winter. On the coasts of Devon and Cornwall hake are most
abundant in autumn and winter.

food.—TVhe hake feeds almost entirely on fish, following and
preying upon shoals of herrings, mackerel, pilchards, sprats, and
anchovies. _Brittle-stars were found in one specimen in the
Irish Survey. According to Day the hake is a nocturnal fish,

—

2 ee ee er oes

THE COD FAMILY 299

retiring to the bottom of the sea where there is less light in
day-time and pursuing its prey in mid-water or near the surface
at night.

In the Irish Survey, of twenty-two specimens examined
thirteen were females, nine males. Spent or ripe females were
taken in March, April, May and June.
Ripe or nearly ripe fish were obtained
at 25 to 80 fathoms.

The eggs of the hake were artificially
fertilised and examined at the Naples
laboratory. They were ‘94 to 1°03 mm.
in diameter (,4; inch) with a single oil-
globule (Fig. 136). The larva hatched in
less than three days, and had an elonga-
ted yolk-sac with the oil-globule at its Fic. 136.—Egg of Hake,
hinder end (Fig. 137). The pigment Se
was yellow and black, the latter absent
from the fin-membrane and forming two bands on the tail.

During the Irish Survey, three small hake, 14 to 14 inches
long, were taken at 80 fathoms in a shrimp trawl in August. Of
larger fish which may be considered to be nearly a year old, one

3 inches was taken at 40 fathoms and one 6 inches long at 115

Fic. 137.—Larva of Hake, newly hatched, magnified ; after Raffaele.

fathoms in March, two 8 inches long at 53 fathoms in May. All
these were captured in trawls, but it is certain that neither young
nor mature hake feed only on the bottom. Small specimens are
frequently taken in mackerel nets, which shows that like the
adults they roam about after prey in mid-water at night.

300 MARKETABLE BRITISH MARINE FISHES

The Rocklings (Motella tricirrata, cimbria, mustela).

Distinguishing Characters—The barbels, and the narrow
anterior fin sunk in a groove in the back, are sufficient to dis-
tinguish these fishes. In the three-bearded species the barbels
are long, one at the chin, one on each side of the snout in front of
the nostrils : in the four-bearded there is one also on the upper lip,
in front of the other pair, while in the five-bearded there is one
pair on the anterior nostrils and a pair on the upper lip. The
three-bearded kind is chestnut on the back, lighter beneath,
and covered with scattered black spots: it grows to 20 inches in
length. The four-bearded kind has no spots, and has not been
found above 14 inches in length. The five-bearded kind is also
without spots, and reaches 18 inches.

Habitat. — The three-bearded kind is common in the
Mediterranean and extends to Norway, the five-bearded kind
ranges from Portugal to Iceland, and the four-bearded from the
British Isles to the Arctic Ocean.

Food—They feed on crustaceans and small fish, and hunt
only at night, remaining concealed in holes or under stones in
the daytime. The anterior dorsal fin is very narrow, and is
frequently kept in a state of rapid vibration in the living fish:
the meaning or use of this curious movement is not known.

The buoyant eggs of the five-bearded rockling were studied
by George Brook in his private aquarium in 1884. They measure
"7 mm. in diameter (not quite ;2) inch). They have a simple
yolk and a single oil globule, although when first shed there are
often three or four oil globules which soon afterwards run
together into one.

The larvee hatched out 54 to 6 days after fertilisation, at
temperatures from 55° to 62°. They were only 2°25 mm. long
(<#5 inch). The oil-globule is at the hinder end of the yolk-sac ;
the fin-membrane is unusually narrow. The black pigment forms
two bands or patches on the tail, as in the larva of the hake.

The later stages of the rocklings are very abundant at the
surface of the sea, in summer, but it is difficult to distinguish
the different species when very young, in fact until the barbels
appear. They are most abundant in May and June, and form
largely the food of the mackerel at that season. They have been

tah

ee ieee ee ee

ed ot SL FO

THE COD FAMILY 301

studied at Plymouth and St. Andrews. The chief peculiarity is
the great length of the pelvic fins, which reach back behind the
vent and are of a deep black colour on their outer halves.
These fins develop very early and are seen in little fish only 6
or 7 mm. long (& or 4 inch) when the rays in the dorsal and
ventral fins have only just developed. The peculiar front
dorsal is not visible. At this stage the skin and body are
somewhat transparent, not silvery, and there is black pigment
on the back. The breast-fins are short and rounded. In speci-
mens from #2 to 1 inch in length can be traced the gradual
development of the silvery livery in the skin, of the front
dorsal fin, and the gradual reduction of the long throat fins.
Fig. 138 represents a specimen a little more than 2 inch long.
Mbovest inch) in leneth); up to 1. inches the fish xsemains

st ae
isaac Shak = RO ee

—— SS
an

Fic. 138.—Young of the Three-Bearded Rockling in the surface-swimming
condition, a little more than inch long.

brilliantly silvery and swims at the surface of the sea, and the
barbels begin to appear on the snout.

In calms during May and June, off Plymouth immense
numbers of these little fish have been seen from the deck of a
mackerel boat. It usually happens at the same time that the
surface of the sea is covered everywhere with great quantities
of minute round grains, which are living things of low organisa-
tion called Voctzluca. These are transparent when seen singly,
but are in places collected in vast numbers into a thick scum of
a salmon-pink colour, which floats in patches and streaks ; this
scum has a peculiar, not very pleasant, odour. The substance is
wrongly supposed by the fishermen to be the spawn of the
mackerel. This (Vocteluca is one of the living things in the sea
which gives out light in the dark, and the sight from the bow of
a mackerel boat going slowly through the water before a gentle

302 MARKETABLE BRITISH MARINE FISHES

breeze is one of the most curious and beautiful in nature. The
little rocklings, or mackerel midges as they are called, dart
away from the boat’s advancing cutwater through the teeming
Noctiluca, making lines of light in their tracks, so that it almost
seems as though the bows of the boat were constantly giving
out rays of light, or as though the vessel were sailing through
an enchanted sea.

After the rocklings grow to 14 inches long they begin to
lose their brilliant, silvery dress, and become dull brown. Then
they leave the surface of the sea, and are found hiding away
under stones on the shore, between tide-marks, or on the bottom
in shallow water. The spots of the three-bearded kind do not
appear until it is several inches in length.

The Tusk, or Torsk (Arosmius brosme).

Distinguishing Characters——Body cylindrical. The skin is
thick and tough, over the fins as well as the body; the vent is
rather far back, the ventral fin commencing beneath about the
thirty-fifth dorsal ray. Scales minute. Colour on the back
ereyish, tinged with yellow, which colour is more pronounced on
the margins of the fins and gives the fish a very characteristic
appearance. Usual length about 18 inches, but the fish grows
tOlOVEL 3 1eEt,

Hlabitat—From Spitzbergen to the latitude of Grimsby,
abundant in the Shetlands and Faroe Islands, also on the
American coast as far south as Cape Cod. Its range extends
to very deep water.

Food.—Chiefly crustaceans and smaller fish.

Breeding.—Of the number examined for Dr. Fulton thirty-
nine were females, thirty-five males; and he calculated the
number of eggs in a specimen 34 inches long, 15 lbs. 54 oz. in
weight, at 2,283,000. Ripe females were only observed at Peter-
head and Lerwick in May and June. In the endeavours to
procure fertilised eggs it was noticed that the testes or soft roes
were very small in comparison with the ovaries or hard roes.
This case resembles somewhat that of the sole. Mr. Duthie
the Assistant Fishery Officer at Lerwick, informed Dr. Fulton
that the males landed were all immature, but when advised to

THE COD FAMILY 303

squeeze the testes in sea-water containing the eggs, he did so,
and fertilisation was effected. The soft roes were only 2 to 3
inches long in males of good size, and had the form of a frilled
riband as in other fish of the cod family.

The fertilised eggs were sent alive from Lerwick to St.
Andrews. They were 1°3 mm. in diameter (over 345 inch), very
nearly as large as those of the cod; but there was a single
large oil globule of a pale red colour. The space between the
egg-membrane and the yolk is small.

The larve hatched out on the ninth day, and were about 4 mm
long (s!; inch). The oil globule was at the hinder end of the
yolk. The black pigment specks were absent from the yolk-sac
and fin-membrane as usual in this family, and formed five
bands on the body, one on the head, one near the vent, and
three on the tail. The coloured pigment is greenish-yellow,
and extends on to the yolk-sac and fin-membrane. The larve
lived in the aquarium for a week, at the end of which time only
a trace of the yolk remained, and the mouth and jaws were
developed. Little change had taken place in the arrangement
of the pigment.

The Sand-eels.

The sand-eels, although usually placed in a different family,
are in many respects similar to the fishes of the cod family.
They are distinguished by the following peculiarities :—The
vent is situated behind the middle of the body, so that the
ventral fin is short; there are no throat fins; the dorsal fin
is single and extends along nearly the whole length of the
back ; the tail fin is separate as in the cod-family ; the gill-open-
ings are wide, and the lower jaw projects into a spoon-shaped
process beyond the upper. This projection of the lower
jaw is the instrument by which the fishes burrow into the
sand.

There are two kinds on the British and Irish shores, the
larger and the smaller or lesser sand-eel. The larger grows
toi2 inches an) leneth tne smaller to 7,inches;. They are so
much alike that it is very difficult to distinguish one kind from
the other, but there seems to be no doubt whatever of their

304. MARKETABLE BRITISH MARINE FISHES

independence. The most conspicuous differences are the following :
—In the larger kind the projection of the lower jaw is greater ;
there are two strong teeth in the roof of the mouth, on the bone
called the vomer ; and the commencement of the dorsal fin is
behind the hinder extremity of the pectoral or breast fin. In
the smaller kind the two teeth in the roof of the mouth are
absent, and the commencement of the dorsal fin is so far forward
that the pectoral extends behind it by one-third of its own
length. Both kinds are rare in the Mediterranean, where a third
species occurs, but extend all along the European shores to the
Arctic Ocean. They are not found on the American side, where
other species of sand-eel take their place.

Sand-eels feed on small sprats as well as on the young of
their own kind, but it seems likely that their food consists partly
also of small crustacea.

Breeding —The spawning of the lesser sand-eel has been
investigated successfully in Scotland, but a complete description
of the eggs and their development has not been supplied.
This species was found to be spawning in June and July,
especially in the latter month, at the mouth of the Tyne, in
Haddingtonshire. The spawning fish were only obtained from
the sand at or below the low water-mark of spring tides, so that
the eggs are not left long out of water, although when not
spawning the fish are often found buried far above low water-
mark. The eggs were artificially fertilised and found to be
globular and slightly adhesive. Under the natural conditions
they attach themselves to the grains of sand at the surface of the
eround and there develop. The attachment is not very firm, and
the egg-membrane is easily burst. The egg of the larger species
when ripe but not fertilised was -7 mm. in breadth, the yolk was
granular, and there was a large single oil-globule of a green
colour. In the smaller sand-eel the perfectly ripe eggs have not
been described, but are presumably similar.

The development of the eggs of the lesser sand-eel occupied
ten days in July, and the larvee when hatched were 3 mm. to 3°5
mm. in length (432; to zoo inch, z.e. less than 8 inch). The absorp-
tion of the yolk also occupied ten days. No figures of the
developing eggs or newly-hatched larva have been published.

Certain very slender larve, 5 to 6 mm. long (4 inch), obtained
regularly in the bottom tow-nets in March, at St. Andrews, are

THE COD FAMILY 305

identified as those of the sand-eel. There is a remnant of yolk
in these, and the vent is in the middle of the body. Larve of
the same length are taken in August. Attempts have been made
to explain these facts: it would appear either that the two species
have different spawning seasons, one in January and February,
the other in June and July, or that the same species spawns
twice in each year, or that the larvze taken in March were
hatched in the previous autumn, the spawning period extending
for some time beyond July. The last supposition, which seems
to me the most improbable, is the one favoured by the naturalist
who specially studied the sand-eel at Dunbar. The fact that
specimens of the greater sand-eel which were obtained at St.
Andrews in May, appeared to be very nearly ripe and contained
some ripe eggs, is opposed to the supposition that this species
spawns in autumn or winter.

THE RED) VOU Ie ee Avie

THE fishes of this family are all very similar to one another
and to our red mullet. They have a rather round body,
with large thin scales, which are firmly attached to the skin.
There are two. dorsal fins which are both short, the first spiny,
the second soft, and a ventral fin below the latter. The pelvic
fins are directly beneath the breast-fins. The head has a front
surface sloping down to the flat under surface, and the jaws and
mouth are at the lower part. Beneath the chin are two long
stiff barbels, which can be thrust forward and moved about or
laid back in the groove between the sides of the lower jaw. Red
mullets occur chiefly in tropical seas, and none are large. They
live in the neighbourhood of the coasts, on the bottom.

The Red Mullet W/ullus surmulletus, and barbatus).

Besides the characters given above it is necessary to mention
the teeth and the colour. There are two rows of rather blunt
teeth in the lower jaw, none in the upper ; none on the tongue,
but rounded ones on the palate. In colour two forms are dis-
tinguished and it has not yet been finally decided whether these
are different kinds or varieties. It seems certain that they are not
different sexes. The one is the plain red mullet, the other the
surmullet or striped mullet, which has a beautiful red colour on
the back and sides, and also three to five bright yellow bands
passing along the sides from the head to the tail. The Italian
naturalist, Raffaele, at Naples, states that the striped fish bred by
themselves in a tank of the aquarium, and that the eggs and
young of the other kind were smaller. It appears, therefore, that

THE RED MULLET FAMILY 307

the two forms are quite distinct. Largest size, 14 to 17 inches in
length.

FHlabitat——F rom the Canary Isles to Norway, including the
Mediterranean. In the British Isles it is rarely taken in numbers,
except on the south and west coasts of England. The plain
form seems to belong to more southern regions, and is said to be
the commoner in the Mediterranean. Mr. Dunn at Mevagissey
has never seen one, and all those that I have seen at Plymouth
have been of the striped kind.

Food.—In the aquarium at Plymouth, where they live for a
long time and thrive, they are especially fond of shrimps, but will
eat also molluscs and worms. They use their stiff barbels to
rake in the gravel and sand at the bottom, and so discover
shrimps that bury themselves, or worms. Even dead food
they feel with the barbels before biting.
They have the habit of rising from the
bottom in a shoal to swim in mid-water
and then settling down again and immedi-
ately beginning to rake the ground: in
these actions they remind one of a flock of
birds. It is curious to see how the red
colour becomes darker when they rise from
the ground and pales away when they 4,, tig: Ree Ver ethie
return toit. The red colour is made more Striped Red Mullet;
intense by removing the scales when the “ter Raffacle.
fish are first caught, and the fishermen
usually perform this operation in order to improve the appear-
ance of the fish in the market.

Breeding.—Vhe spawn has not been studied in this country,
but Raffaele studied it at Naples, where it was shed by specimens
living in a tank of the aquarium. The eggs are of the buoyant
transparent kind. That of the striped mullet is ‘93 mm. or not quite
zs inch in breadth, globular in shape, and the yolk has a single
oil globule. But the yolk is not simple: there is a layer of large
separate masses on the outside, as in the case of the sole and
certain other fishes (Fig. 139.) The spawning took place from
May to August.

The larva hatched out in three or four days. It has one
curious peculiarity, namely that the yolk-sac projects forwards
beyond the front of the head, and the oil globule is placed at the

xe 2,

308 MARKETABLE BRITISH MARINE FISHES

extreme end of the projecting portion (Fig. 140.) There are black
pigment specks on the body of the larva, none on the fin-mem-
brane. The yolk was absorbed and the mouth open when the
larva was seven days old.

The young at later stages are captured at Naples in June,
July, and August: they are about an inch long and are already
provided with the barbels. They differ from the adults in being

“A laa
eA SOCCER Ge —
9 a.

Fic. 140.—Larva of the Red Mullet ; after Raffaele.

more slender, and being completely silvery. Later in the year
they are found in a more developed condition, red spots com-
mencing to appear.

Young mullet, probably a year old and about 3 inches long,
have been taken in seines in Plymouth Sound or its estuaries, in
summer. Like many other fish they retire from the coasts in
winter and approach them in summer, when they are often taken
in seines both on the coast and in estuaries.

CHE SE ASBREAMS

THESE fishes have a deep plump body, large scales, and a
single dorsal fin of which the front part is supported by strong
spines while the hinder part has soft fin-rays. There is a ventral
fin with three spines and a number of soft rays, the soft part
being opposite to that of the dorsal. The pelvic fins are beneath
the breast-fins. There are usually sharp cutting or pointed teeth
in the front of the jaws, and rounded grinding (molar) teeth at
themsides. Where are no teeth on the palate. Whe colour is
usually red on the back, silvery on the sides. They are coast
fishes of the tropical and temperate regions, none extending to the
Arctic or Antarctic seas. They are of very moderate size with
few exceptions.

A number of these fishes are taken occasionally on the
British coasts, especially on the south and south-west coasts of
England and Ireland, but only one of them is at all abundant,
namely the common sea bream (Pagellus centrodontus). It is
distinguished by the possession of molar teeth at the sides of the
jaws and the absence of enlarged canine teeth. It is of an orange-
scarlet colour above, somewhat silvery on the sides. There is a
large black spot on the shoulder, just behind the upper corner of
the gill-cover. The breast fin is long, reaching beyond the vent.

This fish occurs in the Mediterranean and extends from thence
to Norway ; it is taken somewhat frequently round all the coasts
of Britain and Ireland, but is only sufficiently plentiful to be of
commercial importance on the south and south-west coasts of
England and Ireland.

At Plymouth I have found various marine animals in the
stomachs of bream, but most abundantly echinoderms, namely,
brittle-stars and sand-stars and holothurians or sea-cucumbers :

310 MARKETABLE BRITISH MARINE FISHES

I also once found a hermit crab with its companion anemone
on its shell, zoophytes and sea-weed (U/va).

Lreeding and Spawn.—The particulars of the proportions of
the sexes and of the spawning period of this fish have not been
examined. Raffaele found at Naples that the eggs of Pagellus
erythrinus, a species closely allied to the common bream and also
occurring on the south coast of England, were of the buoyant
kind, and that two other species of the family had eggs of this
kind. These buoyant eggs floated separately, and were of the
type with a simple undivided yolk and a single large oil globule.
There can be little doubt, if any, that the eggs of the common
bream are of the same kind. |

It seems as if it would not be difficult to trace out the growth
of these fish at Plymouth with some certainty, as individuals of
particular sizes occur in numbers at certain times of the year.
But this has not yet been done. All that I can say is the follow-
ing. The young, known as “chad” and about 6 or 7 inches
long, are abundant at the mouth of Plymouth Sound in August
and September, and these are probably just over a year old, and
immature. I found fish of a younger stage, only about 2 or 3
inches long, in the produce of sprat seines in the Hamoaze in
September, and think that these were hatched the same year,
their age being something less than six months.

Like most southern fish on the English coasts bream are
seldom taken in winter, retiring at that season to a greater
distance from land or to more southern regions.

trib MACKEREL OR” TUNNY (PAMTEY

THE fishes of this family have two dorsal fins, the first spiny
the second soft; and one ventral fin placed under the second
dorsal. Behind each of these two is a row of small finlets. The
pelvic fins are directly below the pectoral. The tail fin is deeply
forked. The mouth is large and the jaws strong, but the teeth
are small and sharp. The scales are small and without spines,
in the tunnies confined to distinctly defined areas on the front
part of the body, forming a corselet. The gill-openings are wide.
The sides of the tail are sometimes keeled. In some of the tun-
nies the pectoral fins when closed fit into depressions of the skin,
and thus lie level with the surrounding surface.

These fishes are extremely active, migratory, and predaceous.
They swim in shoals and seize their prey with great voracity,
and hunt merely by sight. They pursue other surface and mid-
water fishes, and snap at anything moving through the water,
especially if it is silvery like a small surface fish. The different
kinds are of very different sizes, from the mackerel not exceeding
18 inches long and 24 lbs. in weight to the huge tunny some-
times reaching nearly 10 cwt. These fishes are not confined
to the neighbourhood of the coasts, although the mackerel is
a coast fish, the tunnies ranging through the open oceans.
They belong to the tropical and temperate zones, none of them
occurring in the Arctic or Antarctic Ocean.

The following are the species found in British waters, with
the chief peculiarities which distinguish them from one another.

I. Species of small size in which the two dorsal fins are widely
separated ; the corselet is not distinctly defined ; and there is no
keel in the middle of the side of the root of the tail.

312 MARKETABLE BRITISH MARINE FISHES

1. The Mackerel.—Air-bladder absent, no sign of a
corselet.

2. The Spanish Mackerel.—Air-bladder present, a rudi-
mentary corselet of somewhat enlarged scales below the
pectoral fin ; eye larger than in the common mackerel.

II. Species of small size with two dorsal fins widely sepa-
rated ; acorselet on the breast region ; and a keel in the middle of
the side of the root of the tail.

3. The Plain Bonito.

III. Species of large size in which the first dorsal reaches to
the beginning of the second; the corselet very distinct, and the
central keel on the root of the tail well developed.

4. The Short-finned or Common Tunny.—Corselet
distinct ; breast-fin not reaching back to the commence-
ment of the second dorsal.

5. The Long-finned Tunny or Germon.—Corselet obs-
cure ; breast-fin reaching behind the end of the second
dorsal.

6. The Bonito.—Breast-fin quite short ; corselet larger than
in either of the previous two; four or five long curved
blue stripes passing along the sides and belly, bending
upwards behind.

. The Pelamid or Belted Bonito.—Corselet much
smaller than in the last; broad bands passing straight
down from the back, narrow bands slanting across them
downwards and forwards.

N

The Spanish mackerel is commoner in the south, ze. in the
Mediterranean and at Madeira than on the British coasts, and as
no practical importance belongs to its history or that of the
tunnies in this country, only the common mackerel will be here
considered separately. The Remora or sucking fish is placed in
the family but has seldom been taken in British seas.

The Mackerel (Scomder scomber).

Distinguishing Characters.—Eleven to fourteen spines in the
first dorsal fin, which commences a little behind the breast fin.

THE MACKEREL OR TUNNY: FAMILY 313

Five or six finlets behind the second dorsal and the ventral.
Scales minute, almost undistinguishable on the sides and belly.
A single row of sharp teeth in the jaws, and others on the tongue
and roof of the mouth. A slight keel at the base of each lobe
om the tail; but none im thecentre of the root of the tail. Eyes
with transparent upright fixed lids in front and behind. <A
number of wavy black bands pass down from the mid-dorsal line :
between them the colour is deep green: the sides and belly are
brilliantly silvery with iridescent reflections. The shape of the
body is somewhat slender, sharp at both ends, somewhat narrow
from side to side.

Varieties are seen in which there are small black spots or
irregular scribbled lines, instead of the usual wavy bands.

Flabitat—From the south of Norway to the Canary Isles,
and throughout the Mediterranean. In the British Isles, most
abundant in the Channel and northward to Norfolk, but they
occur also to some extent along the east coast of Britain to the
Orkneys: also in the Irish Sea, and on the south and south-west
coasts of Ireland.

food—TYhe mackerel is able to live on minute surface
creatures, especially crustacea, when small fish are not available.
It appears to feed at these times like herring or pilchard, strain-
ing the swarms of small creatures through the gill rakers, which
are as well developed as in the herring family. Thus at Ply-
mouth in May I found only the minute crustacea called copepods
in some stomachs, in some a quantity of the green slimy vege-
table matter, which was then abundant in the sea, and amongst it
copepods and buoyant fish eggs. In August I found small sprats,
and in a considerable number examined in November, only small
pilchards between. 3 and 4 inches long. The mackerel enter
Plymouth Sound and such bays to feed on the young sprats in
July and August. ;

Lreeding—The number of eggs in a single female has been
calculated to be from 430,000 to 540,000 in specimens 18 to
20 ounces in weight.

Sars first described the buoyant eggs of the mackerel in 1865.
I studied them at the Plymouth Laboratory in 1888. In the
latter neighbourhood spawning takes place from the end of May
to the latter part of July, and the period seems to be distinctly
limited within these times. The spawning fish are found from

314 MARKETABLE BRITISH MARINE FISHES

14 to 50 or more miles from the coast. Ripe males are taken on
hooks, but not the ripe females, which are caught in nets. The
stripping and fertilisation of the eggs are extremely easy. The
temperature at the surface of the sea at the spawning period was
about 54°, and its density 10269. The mackerel ova although
buoyant in the open sea water where they are naturally shed,
are heavier than those of the lemon
dab and other fishes, and sink in water
in which the latter float.

The egg (Fig. 141), is globular and
transparent, the yolk is simple but
has a single large oil-globule. The
breadth of the egg is 1°22 mm. (not
quite 4, inch, more exactly 78)
inch). The eggs hatched on the 6th
day at the temperature of 68°.

Fic. 141.—The egg of the Mac- The newly hatched larva (Fig.
kerel, alive and magnified. 142) is 4°23 mm. long (or not quite
2 aneh)., The mouthiis: net open,

the oil-globule is at the hinder end of the yolk-sac, and the
end of the intestine is just behind the latter. The pigment
consists of black and greenish-yellow specks, present on the
body and yolk-sac but absent from the fin-membrane. The
larve were not reared in confinement to a greater age than four
days (Fig. 143), when the yolk was very nearly absorbed, and

Fic. 142.—Larva of the Mackerel, newly hatched, alive and magnified.

the mouth and jaws were developed, but the formation of the
fin-rays had not commenced. Pigment was still absent from the
fin-membrane. The later stages and transformation of the
mackerel do not appear to have been studied.

Growth and History of the Young—lI did not procure any of
the young of the year while at Plymouth. The smallest mackerel

THE MACKEREL OR TUNNY FAMILY 315

I examined were taken in anchovy nets in November, 1891,
between the Sound and the Eddystone. These were 6 inches to
8°3 inches long, and I consider them all to be too large to be
derived from the previous spawning, and to be therefore in their
second year. They weighed from less than an ounce to over two
ounces. A few specimens taken in June on whiffing lines
measured 8°7 to 9°3 inches, and these also might be a year old.

The smallest ripe specimens I have examined were 11°6 to
129 inches long, weighing 7} to 9 ounces, the large ripe specimens
being 16 or 17 inches long. We may consider the smaller
specimens to be two years old, and the others older.

The young fish do not seem to enter bays or estuaries
commonly in large numbers, although I found a few yearling
mackerel in the produce of the ground seine in the Hamoaze
in September. The young of the year, about 3 inches long, have

SLE a = SSS

CLL APL A WP Pd ELLE I le Sp Ness
== ga NN ia
(x SS Prva
Qo

SES

ae

oes

v

ges

Fic. 143.—Larva of the Mackerel, four days old, alive and magnified.

been observed by Mr. Dunn at Mevagissey, in August and Sep-
tember, but I have never seen or heard of any of that size in
Plymouth Sound. At present I am inclined to think that the
young in their first half-year remain for the most part out in
the open sea.

Migrations —At Plymouth there is no month in the year in
which mackerel are not taken, but they are scarcest in December
and January. This is presumably the time when the fish are
farthest from the coast, feeding in the more distant water where
the temperature is higher. The few caught in those months in
1889-90 were taken 15 to 40 miles south of Plymouth. In
February they become more abundant, the largest catches being
4,000 to 5,000, the fish still a long way off, 20 to 30 miles from
Start Point. In March and April the fish are still a long way
off, at least 30 miles from the Sound in March, 20 miles in

316 MARKETABLE BRITISH MARINE FISHES

April. In May, however, the fish approach the land while
spawning, being taken at the end of the month only a mile or
so outside the Breakwater. In June they remain inshore, but
these are the smaller fish, and much larger fish are caught off
Ushant and the Scilly Islands. At this time fishing by hooks
commences. In July and August mackerel enter Plymouth
Sound, where they are taken by whiffing lines, and in good years
by seine. After the beginning of September they leave the
Sound, and are caught a few miles south of the Eddystone. In
October and November they are caught from four miles south
of the Eddystone, to 20 or 30 miles south of Start Point. Off
the coasts of Norfolk and Suffolk there is a valuable drift-net
fishery for mackerel, which is carried on in May and June, and
also from the Ist September to the middle of November. I do
not know why they should be absent in July and August.
It seems probable, however, that these fish only visit this part
of the North Sea in summer, that they spawn there in May
and June, and that they retire to the Channel in the latter part
of November.

Along the east coast of Britain north of Norfolk very few
mackerel are taken, only a few hundreds being taken in the
herring nets in summer. On the west coast of Scotland they are
more plentiful. On the west coast of England they are taken
regularly in summer in some abundance ; at the Isle of Man the
fishery lasts from May to September. In Ireland the principal
mackerel fishery is in the south-west, but they are taken in
summer all along the west coast.

Mackerel also regularly appear on the south-west coast of
Norway, in the Skagerack, and on the west coast of Sweden in
May, and give rise to a considerable fishery.

It is a common belief among fishermen that mackerel are
blind at the beginning of the year, having a cloudy film over the
eyes which obstructs their vision, and which disappears in
summer. In support of this belief it is pointed out that they
only take a bait in summer. I have never seen anything in the
condition of the eyes to warrant this belief, although I have
examined plenty of mackerel at all seasons of the year. The
two fleshy transparent upright lids are always present ; there is
an opening between them where the eye is uncovered. But I
have never seen any cloudiness in these lids, nor anything

THE MACKEREL OR TUNNY FAMILY 7

Los)

peculiar in the appearance of the eyes in winter or spring. Itisa
fact that fishing for mackerel with hook and bait is usually only
carried on in summer, but this is apparently sufficiently explained
by the fact that this kind of fishing, usually called “ whiffing,”
is practised by small long-shore boats which do not go far from
shore, and the mackerel only approach close to the land in
summer. The fish are more readily taken on hooks after the
end of June, because in the spawning season they take less food,
especially the females, which for a time cease to feed altogether.

THE FAMILY OF THE SCAUDS, OR SIGhsE
MACKERELS

THIS is a large family of fishes belonging to tropical and
temperate seas, and more abundant in the tropics. The fishes
included in it show considerable differences from one another,
and it is not easy to mention peculiarities which are common to
them all. The body is always more or less narrow from side to
side, sometimes thin and of great vertical height ; the eyes are
on the sides of the head. The spiny front dorsal fin is shorter
at the base than the second, and in many species reduced to
short separate spines. The lateral line is in some armed with
bony plates. There are sometimes separate finlets behind the
dorsal and ventral fins as in the mackerel.

The only fish of this family which is common in British seas
is the scad or common horse-mackerel, but the pilot-fish and
others have been taken occasionally on our coasts.

The eggs are not well known, but are probably buoyant in
the majority of species, if not in all. One species is the skip-
jack or blue-fish of the coasts of the United States, and the
eggs believed to belong to this fish have a layer of yolk
segments and a single oil globule like those of the red mullet.

The Scad, or Horse-Mackerel.

Distinguishing Characters —TVhis fish has a front dorsal fin of
eight spines, a long soft second dorsal and ventral; there are
two spines in front of and separate from the ventral. The most
marked peculiarity is the lateral line, armed throughout its
length with plate-like bony scales, which towards the hinder end
of the fish are keeled. The scales present on the head and rest
of the body are very small. The colour is a dark bluish on

THE FAMILY OF THE SCADS, OR HORSE-MACKERELS 319

the back, silvery on the sides and belly. The tail is forked.
The greatest length attained is 20 inches.

Habitat—This fish is found almost all over the world,
extending from the Mediterranean northwards to Denmark,
southwards to the Cape of Good Hope, and found also in
China, Australia, and Chili; it appears to be absent from the
western shores of the Atlantic. In Britain and Ireland it is
found all round the coasts, but becomes scarce in the extreme
north. In food and habits it closely resembles the mackerel.

Breeding. —The fertilised eggs have not been obtained and
examined. In May, 1894, Mr. Holt obtained at Grimsby some
apparently ripe females from the North Sea, but they had been
caught the day before he received them. The eggs were quite
transparent, and floated in water at Cleethorpes, which was
not so salt as that of the sea. In breadth they were 1°03 to
1°09 mm. or 4; inch. There was either a single oil globule or
two or three which united afterwards. The yolk was divided
throughout its substance into large masses, and it was remark-
able that these projected at the surface, so that the surface of
the yolk was not smooth and even as it usually is. Artificial
fertilisation was not successful, and the eggs did not live in
sea-water more than forty-eight hours. It seems very probable
that the peculiarities of these eggs, different from any known
in others, are due partly to the fact that they were not perfectly
ripe, partly to the fact that the females from which they came
had been dead for twenty-four hours. It will probably be found
that the eggs of the scad when fertilised are like those which
are believed on good evidence to belong to the American blue-
fish, and that the yolk-masses, as described by Mr. Holt, simply
show an unnatural or imperfectly developed condition of the
outer layer of yolk segments which is natural in the fertilised
eggs.

Although I have not examined the eggs at Plymouth, I have
obtained the young in the tow-net at the surface in August and
September. I took four specimens in all, from 1 inch to 2 inches
in length, from two to five miles off the coast. These were fish
which had passed through their transformations and developed
the characters of the fully developed scad; and as spawning
appears to take place in May and June their age may be
reckoned at from two to four months.

THE. JOHN DORYVEAMIEY,

THIS family is rather closely allied to that of the horse-
mackerels. Its chief characteristics are that the body is high
and narrow from side to side; that the front dorsal fin consists
of a few strong spines which are elongated; that the second
dorsal is not completely separate, and like the ventral is
rounded behind. The mouth is constructed in a curious way
so that when it is opened the upper jaw is thrust far forward,
and the whole mouth forms a kind of long tube. The tail is
rounded at its hinder edge, while in the horse-mackerels it is
more or less forked.

The fishes of this family inhabit the seas of the temperate
regions. They are slow swimmers, and feed chiefly on smaller
fish. So far as known their eggs are buoyant. Two species are
common in British waters :—

1. The Boar-fish or Cuckoo. —Orange-red in colour; scales
small but with spines making the skin very rough. Mem-
brane of the first dorsal not produced into filaments.

. The John Dory.—Scales small, and not spiny ; skin
smooth. Membrane of the first dorsal prolonged into
filaments. Colour olive or brownish with yellow bands ;
in the centre of each side a round black spot surrounded
by a yellow ring.

iS)

The Boar-fish, or Cuckoo (Cafvos afer).

Distinguishing Characters.—Besides those above mentioned,
the teeth in the jaws are minute ; there is a row of small spines
on the gill-cover; there is a roughened bony ridge along the
bases of the second dorsal and ventral fins, but no spines. The

THE JOHN DORY FAMILY 221
ventral fin is similar to the second dorsal, and there is a small
front ventral fin consisting of three small spines. The first ray
of the throat fin is thick, long, and rough. It is a small fish, not
exceeding 7 inches in length.

The fish is found in the Mediterranean, and on the Atlantic
coast from Madeira to England. It approaches the coast in
summer from May to October, and off Devon and Cornwall is
very abundant ; north of the English Channel it has been only
occasionally taken. It swims near the bottom and hundreds
are taken by the Plymouth trawlers in summer time in every
haul of the trawl. The limits of the spawning period I do not
know, but I found numbers of ripe specimens on August 15th,
1887, on board a trawler to the east of the Eddystone, and I
fertilised some of the eggs, which were buoyant and transparent.
The egg is ‘97 to 15 mm. in breadth or about 5 inch, and is
globular. The yolk is simple and undivided, and there isa large
single oil globule. None of the eggs were hatched and the
larva and its transformations have not been traced out.

The John Dory (Zeus facer).

Distinguishing Characters—Along the base of the dorsal fins
on each side is a row of spines, those at the base of the second
dorsal being double ; similar spines at the base of the hinder
ventral fin. The front ventral fin consists of four strong, thick, spiny
rays. The throat-fin is a little in front of the breast-fin, and is
nearly as long as the first dorsal, filaments included. The mouth
is large and much protruded when open. The largest specimen
was 225 inches long, and 18 lbs. weight.

FHlabitat——Like the boar fish, the dory is a fish of the
Mediterranean, and is spread on the Atlantic coast from Madeira
to Norway. It is common in the English Channel and Bristol
Channel, where it has considerable importance in the market,
and occurs all round the coast of Ireland ; but on the east coast
of Britain and in the North Sea, it is rare. In the Irish Survey
it was not taken at greater depths than 40 fathoms.

The dory feeds entirely on fish. At Plymouth from December
to March, I found only pilchards and herring in their stomachs,
when the half digested remains were recognisable at all. During

¥

322 MARKETABLE BRITISH MARINE FISHES

the Irish Survey only sand-eels and herrings were recognised. In
the aquarium at Plymouth, I have noticed that the dory has a
peculiar and interesting method of securing its prey. It does
not overtake it by superior speed like the mackerel, or lie in
wait for it like the angler, but stalks it and approaches it by
stealth. It is able to do this in consequence of the extreme
thinness of its body, and the peculiar movement of its hinder
dorsal and ventral fins. The dory places itself end on towards
the fish it desires to devour, and in this position it is evident that
it excites no alarm on the part of its prey. The appearance of
the dory seen in this way is a mere line in the water, to which
no particular significance can be attached. I have not particu-
larly noticed the effect of the ribbons of membrane, which project
from the dorsal fin. But I have observed that the movements of
the dory are very gradual, except in turning: it alters the
position of its body by a turn of the tail or side fins, and then
slowly swims forward by vibrating the second dorsal and ventral,
a movement which causes very slight disturbance of the water.
The whole appearance of the dory in these actions is suggestive
of suppressed excitement, his eyes being fixed on his prey. Ido
not recollect seeing him actually swallow another fish, but have
no doubt that he gets near enough to a sprat for example, with-
out alarming it, to seize it by the sudden elongation of his
curious jaws.

Breeding —In the Irish Survey ripe females were found in July
and August, and one spent in June. At Plymouth I found them
ripe in August. This is enough evidence to indicate the spawning
season, but unfortunately no one has examined the eggs. In all
probability they are of the same type as those of the boar-fish
above described. The larva and their transformation also are
at present unknown, but considerable evidence has been collected
concerning the growth of the young. In summer, from June to
September, specimens from a little less than 5 inches to 7°3 inches
in length are taken in considerable numbers by the trawlers at
Plymouth, at depths from 5 fathoms to 35 fathoms. It is clear
that these cannot be less than a year old, and there is no reason
to suppose that they are more. Smaller specimens are taken in
autumn and winter. The only one I have recorded was 1°7 inch,
taken in Cawsand Bay, Plymouth Sound, at the beginning of
October. This one I consider to have been about three months old.

THE JOHN DORY FAMILY B28

In the Irish Survey the smallest ripe male was 11 inches
long, the smallest ripe female 15 inches ; but only a small number
were obtained.

Migrations —On the coasts of Devon and Cornwall, the
movements of these fish do not appear to take the form of
regular migrations. They seem to leave the bays and shallow
waters in winter, but at that season are taken by the trawlers at
depths of 30 to 40 fathoms. Considering the inactive mode of
life of the fish, it is not surprising that it should be taken in
the trawl, when swimming near the bottom, but the character of
its food shows that it is not specially addicted to the neighbour-
hood of the bottom, but able to rise to any level: and the fact
that it possesses an air-bladder also shows that it can swim in
mid-water.

THE GURNARD FAMILY.

THIS family includes both the gurnards and the bullheads,
the latter being of no commercial importance. The distinguish-
ing characters are that the bones of the head are armed with
backward-directed spines ; that there are two dorsal fins and one
ventral, the second dorsal and ventral being long and opposite
to one another and supported by soft or flexible fin-rays, while
the first dorsal has spiny rays, and is shorter than either of the
others. The breast-fins are large, the pelvic or hinder pair on
the chest beneath them; the hinder edge of the tail-fin is rounded
or straight. Scales are well developed and more or less spiny
in the gurnards, absent in the bullheads. The body is rather
round and plump.

These fishes are always of rather small size, and not powerful
or active swimmers. They live on the bottom, near or not far
from the coasts, and are found in all seas, arctic, temperate, and
tropical. The following are found in British and Irish seas:

I. Species in which the skin is soft and scaleless, and the
breast fin in the ordinary condition.

1. The Miller’s Thumb.—No spine on the opercular bone
or above the eye. First dorsal fin narrow, only half as
high as the second. Not more than 5 inches long. Lives
in fresh water.

. Father-lasher, or Short-spined (Cof¢w#s).—Sea-scorpion.
First dorsal fin nearly as high as the second. A spine
above the eye, and four principal spines on the gill-cover,
the uppermost of which is short and smooth.

. Long-spined (Co//ws)—Five principal spines on the gill-
cover, the uppermost of which is long and rough.

4. Four-horned (Coftus).—Two pairs of large rough

i)

Oo

THE GURNARD FAMILY 325

tubercles on the upper surface of the head, and a row
of similar tubercles or two rows along the sides.

II. Gurnards, species in which the head is strongly armoured
with bony plates, and has an angular wall-sided shape ; spines
along the lateral line and along the bases of the dorsal fins. The
three lowest rays of the breast fins separate and independently
movable, used as fingers.

5. The Grey Gurnard.—No spines along the bases of the
dorsal fins, spinous points along the lateral line.’ Grey in
colour with white spots.

6. The Red Gurnard.—A ridge along the base of the dorsal
fins with about twenty-seven spines ; scales on the lateral
line without spines, but having the form of narrow plates
across the line.

7. The Tub-fish, Tub, Sapphirine Gurnard, or Latchet.
—Spines along the base of the dorsals. Pectoral fins
much enlarged, reaching behind the commencement of
the ventral fin, and coloured with rich blue colour on the
hinder surface, which in life is displayed upwards.

8. The Piper.—Bones of the head above the upper jaw pro-
jecting in two large flat plates, which are toothed along
their front edges. Pectoral large as in the tub, but not so
broad and not brilliantly coloured.

g. The Long-finned Gurnard.—The second spine of the
dorsal fin much elongated ; a shining silvery band along
each side of the body.

10. The Streaked Gurnard.—Lateral line with saw-like
spines ; spines along the bases of the dorsals. Raised
ridges passing from the back in a direction slanting
forward down the sides.

The habits and development of the sea-scorpions are very
different from those of the gurnards, and perhaps it would be
more reasonable to consider them as belonging to distinct families.
The former are found in very shallow water, being often found
above low water-mark, lurking among stones, rocks and sea-weed,
and darting out at any prey which comes near them. The eggs are
large and adhesive, and are deposited in clumps which adhere to
stones or other objects on the bottom. The gurnards on the

326 MARKETABLE BRITISH MARINE FISHES

other hand, live in deeper water, and their eggs are of the
transparent buoyant kind.

The four-horned cottus belongs more particularly to the
Arctic Ocean and the northern part of the Baltic. It is said to
have been taken on the north coast of England and at Wey-
mouth, but neither this nor the fresh water form need be further
considered here.

The Bullheads (Cottus scorpius and C. bubalts).

The long-spined form is smaller than the other, not exceeding
12 inches in length, and as usually seen only 6 to 9 inches. It
is found in the arctic regions and in America, but seems to
extend further south than the short-spined form. It is the only
species I have found at Plymouth, and is much the commoner
species on the west coast of Ireland, while at St. Andrews the
short-spined form is commoner. The largest specimen of the
sea-scorpion or short-spined form obtained in Britain was
15 inches long, but the same species is said to reach 6 feet in
Greenland.

In colour the bullheads are brownish or yellow, with large
irregular markings of black and white. Occasionally on the
south coast, brilliant red or carmine coloured specimens of the
long-spined species are taken. These come always from rather
deep water, and I think they live among red sea-weed. - The
carmine-coloured pigment is present in the ordinary dull and
dark-coloured specimens found on the shore, but in these it is
much obscured by the large amount of brown or black pigment
present. In the carmine specimens, the black is reduced and the
carmine colour comes into view. The carmine colour extends all
over the back and sides, except where it is relieved by patches
of pure chalk-white and black: there are also small yellow
marks chiefly on the fins, so that these fish present a very
striking and gaudy appearance. It seems possible that the
variety is not permanent, but due to the influence of coloured
surroundings, that is of the action of coloured light, on the
changeable pigment-cells of individuals.

The eggs are deposited in the earlier months of the year,
February to April or later. The egg-masses in the smaller form

THE GURNARD FAMILY 32

are somewhat larger than a walnut, in the other about as large as
a man’s fist. They are often found between tide-marks at low
water. It is stated that the male guards them, and it is probable
that they require the attention of one or other of the parents, to
keep a current of water over and through them, but I know of
no direct observations in this case. The eges of the sea-scorpion
are =2, inch in breadth, of the other somewhat less. The yolk is
made up of minute globules, and is of a red or orange colour in
the sea-scorpion, yellow or nearly colourless in the long-spined
species. There are several oil globules of various sizes, but
during development they unite together into one, which is placed
at the front end of the yolk in the hatched larva.

The development occupies some weeks. The clumps can
often be found with the larve just ready to hatch out from them.
These larvee are much larger, more developed, and more active

ee é kateb

MELEE
LE

Fic. 144.—Newly hatched larva of the Long-spined Bullhead, alive and magnified.

than any larve hatched from buoyant eggs. In fact, in adhesive
eggs generally there is a considerably larger quantity of yolk,
the development in the egg is more prolonged, and in consequence
of this, the fry when first hatched are in a more developed
condition. The larva of the sea-scorpion is about 7°5 mm. long
or 3, inch, that of the long-spined bullhead (Fig. 144) 5°7 mm., or
a little more than ,2, inch. The differences in character between
the two kinds are very slight. The head is rounded and large,
and the mouth and jaws well developed. The abdominal region
is very short, and the tail long. As usual in eggs developed at
the bottom, red blood is seen coursing in veins over the yolk-
sac. The primitive fin-membrane passes from behind the head
round the end of the tail, to the hinder end of the yolk-sac, where
the intestine opens: this membrane is enlarged at the tail end,
and narrower at the root of the tail. But the most char acteristic

328 MARKETABLE BRITISH MARINE FISHES

feature in the larva is the mantle of black star-shaped pig-
ment specks in the roof of the belly cavity: the larva being
transparent, this pigment is very conspicuous. There are also
yellow pigment and a few black specks on the head and yolk-sac,
but at first there is none in the tail.

The Gurnards (77i¢/a gurnardus, cuculus, hirundo and lyra).

The differences among these fishes in importance and in
history are so slight that nothing would be gained by giving a
separate account of each.

Distinguishing Characters.—I\t should be understood that the
bones which cover the surface of the head are the same which are
present inthe heads of other fishes, but here arethicker and broader,
and bare, no soft skin extending over them. The bones of the gill-
cover are furnished with strong spines. The three separate rays
of the breast fins which form one of the most remarkable pe-
culiarities of these fishes remind one somewhat of the legs of an
insect, but are more properly to be compared to our own fingers,
since they are part of the divided extremity of limbs which
correspond to our own arms. Their use, too, is more that of
fingers than of legs, since they are employed, like the barbels of
other fishes, to feel the ground and rake over loose stones, in
order to discover small crustacea and other animals on which the
fish feeds. These fishes have another interesting peculiarity :
they utter sounds, resembling faint grunts. These sounds are
produced in the air-bladder. That organ is entirely closed, and
its walls contain well developed muscles, which by their contrac-
tion, drive the air from one part of the bladder toanother. In the
tub, or latchet, the air-bladder consists of three portions, a larger
central chamber and a smaller chamber on each side, communi-
cating with the central chamber at the front end. At the hinder
portion of the central chamber there is a partition running in a
slanting direction across it, and in the middle of this partition is
a round opening. The air is pressed to and fro through this
opening, and so the sound is produced.

The use of the sounds is not well understood, no thorough
investigation of the question by means of experiments and obser-
vations on living fish in aquaria having yet been made. But it

— a eS

THE+GURNARD FAMILY 329

seems probable that the fish communicate with one another by
these sounds. The sounds are not usually heard by an observer
when the fish is in the water, because they do not pass readily,
if at all, from the water to the air, but if the fish is taken out of
the water they are heard distinctly enough.

The piper is the largest of the species, the tub next, the grey
gurnard next, and the red the smallest. The piper reaches a
length of 2 feet, and the tub grows nearly as large. The grey
gurnard is seldom seen as long as 18 inches, and the red gurnard
is usually smaller. In colour all the gurnards except the grey
are red or brownish-red on the back and white on the sides: the
sides and belly are not brilliant or silvery. The hinder surface of
the breast-fin in the sapphirine gurnard, or tub, is blue at the
margins and reddish within the margin, while the central part is
blue with black blotches.

Flabitat—Gurnards are found in tropical and temperate seas,
not extending to the arctic regions. Of the species here con-
sidered the grey gurnard is the most northern, extending from
the Mediterranean to Norway and the Baltic. It is found all
over the North Sea as well as on all the coasts of Britain and
Ireland. The red gurnard also extends from the Mediterranean
to Norway, but is much less abundant in the North Sea and on
the east coast of Scotland than the grey ; in fact, it is scarce in
the North’ Sea,

The tub has a range very similiar to that of the red gurnard:
it is found on the coast of Norway, and in small numbers on the
east coast of Scotland, but is rare in the North Sea except in the
southern narrower part and in the Heligoland Bight ; it is fairly
plentiful on the south coast of England, south and west coasts of
Ireland. The piper is still more confined to southern regions,
not being taken on the east coasts of England or Scotland, or in
Norway. The long-finned gurnard and the streaked gurnard
have been taken chiefly on the south coast of England. The
greatest depth at which the grey gurnard was taken in the Irish
Survey was 80 fathoms, but the piper was taken at 144 fathoms,
and the red gurnard has been taken at 165 fathoms.

food.—In the Irish Survey specimens of all four species were
captured and examined. The food in all was varied, crustacea
being in greatest proportion. Of the crustacea the chief forms
were crabs, especially swimming crabs, and shrimps. Fishes

330 MARKETABLE BRITISH MARINE FISHES

were next in order of frequency, and were usually sand-eels or
sprats, though dabs and other flat-fishes were occasionally found.
In the piper, besides crustaceans and fish, sand-stars were also
found, and molluscs were occasionally present in both piper and
tub.

Breeding —In the grey gurnard, Dr. Fulton found there were
409 females to 100 males, while the females were very slightly
larger than the males, the proportion in length being as 108 to
100. The number of eggs in the ovaries at one time was found
by computation to be from 192,000 in a specimen 124 inches
long, to 297,000 in a specimen 13} inches.

In accordance with the superiority of the females in number
the spawning period is prolonged. In the Irish Survey ripe
female grey gurnard were observed in March, April, May, June,
and July. On the east coast of Scotland they have been observed
from April to August. I found both the red and the grey kind
spawning off Plymouth in April and May.

There is no evidence at present of the preference by gurnards
of particular grounds for spawning. They spawn at various
depths and distances from shore, in Scotland according to Ful-
ton, both in territorial and extra-territorial waters. The least
depth at which ripe females were taken, on the west coast of
Ireland was in the case of the red gurnard 13 fathoms, in the
case of the grey about 10 fathoms.

The Eggs and thetr Development.—The eggs of the red and
grey gurnards have been studied; those of the tub and piper
and the rest have not yet been examined. The eggs have been
obtained by artificial fertilisation, and also by tow-nets from the
sea. They have been hatched without difficulty in aquaria at
Plymouth and at St Andrews. They are of the buoyant trans-
parent kind, and belong to the type with a simple undivided
yolk and a single large oil globule. The eggs of the two species
resemble one another very closely (Fig. 145). In size those of the
grey gurnard are very slightly the smaller, on the average, but in
both cases there is considerable variation, those of the grey
being from 1°42 to 1°55 mm., those of the red from 1°47 to 1°61
mm.in, breadth), (In’ fractions ‘of an inch’.*, to .-, or abou
zo is sufficiently exact for most purposes.) In both cases the
oil globule when the egg is first shed is brownish-yellow, or
copper-coloured, but in the later stages of development the

THE GURNARD FAMILY 331

colour gradually disappears. Mr. Holt has observed that there
are often two or three oil globules in the eggs as they come
from the fish, but they usually unite into one in a very short
time.

At Plymouth the eggs of the red gurnard hatched in six
days: at a lower temperature at St. Andrews those of the grey
took thirteen days to hatch. The newly hatched larva of the
red gurnard is 3°77 mm. in length (not quite # inch). The
intestine ends close behind the yolk-sac, in which the oil globule
ismae the hinderiwend' ihe
mouth is not open: the rudi-
ments of the breast-fins are
unusually large. The pigment
is black and orange, and is
present over the body and
yolk-sac, and along the edges
of the longitudinal fin-mem-
brane.

The larve of the grey gur-
nard were kept alive in aquaria
at st. .Andrews. by.) “Prof.
McIntosh for three weeks
after hatchine. Atthe end of F16- 145-—Egg of Red Gurnard, alive

A 5 = and magnified.
this time they were about 6 o.g. oil-globule ; e. eye ; 2¢. heart ; az.
mm. ES inch) long, and the organ of hearing ; 7. notochord, or
yolk aeabsorbedt Only Ane rudiment of backbone.
primitive fin-rays were present
in the breast-fins, none in the longitudinal fin-membrane.

A succession of later stages were obtained by the tow-net in
St. Andrews Bay at 23 fathoms. They were from 6 mm.
upwards in length, and their stomachs contained, as usual
in young fishes at these stages, the minute crustacea called cope-
pods. They showed the most interesting changes in the process
of transformation to the fully developed fish. At 2 inch in
length (Fig. 146) the development of the permanent fins has made
considerable progress. The two dorsals, ventral, and caudal are
all marked out and provided with primitive fine fin-rays, but the
first dorsal is not separate from the second. The breast-fins are
of proportionally enormous size, reaching nearly to the base of
the tail, and provided with the permanent fin-rays. It is interest-

332 MARKETABLE BRITISH MARINE FISHES

ing to note that in this stage the three lowest rays are not yet
separate, but are connected to the rest of the fin by membrane
as in other fishes. The throat-fins, or second pair of side-fins,
are present, but shorter and narrower than the breast-fins. This
stage was obtained towards the end of August. An older stage,
also procured in August in St. Andrews Bay, was 22 mm. long
(over + inch). It has nearly all the characters of the full grown
fish, but is more brilliantly coloured, and the scales and spines
are not fully developed. In this stage the three fingers of the
breast-fins on each side are separate, except at their bases, and
these fins themselves are shorter in proportion to the length of
the fish, reaching a little beyond the commencement of the
ventral and second dorsal. The spines at the bases of the dorsal
fins and along the lateral line were present in specimens 24 mm.
long, or very nearly I inch.

Fic. 146.—Young of Grey Gurnard 2 inch long ; after Prince.

Young grey gurnards 2%, 3, 47, and 63 inches long were
taken at St. Andrews in June, and 4¢ to 63 inches in May.
There can be little doubt that these are nearly a year old. During
the Irish Survey young grey gurnards of the year, } to } inch
long, were taken at less than 5 fathoms in May, others under
2 inches were taken at depths between 5 and 45 fathoms in
August. It appears, therefore, that these early stages are not
confined to very shallow water. A large haul of the yearling
fish, consisting of 300 specimens, 3 to 74 inches long, was taken
near the Arran Islands at 20 to 25 fathoms in April.

Size at which sexual maturity 7s attained —According to the
observations made in the Irish Survey the smallest ripe male
grey gurnard was 7 inches long, the smallest ripe female 9}
inches. The red gurnard of both sexes were mature at 13
inches. Of the tub or sapphirine gurnard, males were ripe at

THE GURNARD FAMILY 333

12 inches and upwards, but a female at this size was immature.
As far as the evidence goes it indicates, as will be seen, that
maturity is not attained until the second season after hatching.

Migrations and habits —We have no evidence at present of
any regular migrations of gurnards, except that like many other
fishes they appear to come nearer inshore in summer. Couch
and other naturalists assert that they sometimes rise to the sur-
face and sport there. In the aquarium at Plymouth and else-
where it has been observed that they do not live long, being
apparently unable to bear confinement. The sapphirine gurnard
has the curious habit of spreading out its breast fins with the
brilliantly coloured surface uppermost, when it is alarmed, as by
the approach of the hand or a stick. The use of this to the fish
or the reason of it is not obvious. The piper probably uses its
peculiarly armed snout to dig up the gravel and turn over stones,
but this habit has not been observed.

GREY, MUELETS :

THESE fishes are all closely similar. They have an elegantly
shaped, somewhat elongated body, rather rounded, covered with
smooth-edged scales. There are two short dorsal fins, the front
one composed of four spines. The ventral fin is opposite the
second dorsal. The pelvic or throat-fin is behind the breast-fin.
The tail-fin is large and somewhat forked. The teeth are very
feeble or absent. These fish belong to the tropical and tem-
perate shores, and frequent harbours, inlets, and estuaries. They
feed largely on the vegetable growths of green or brown colour
which form a coating over all objects in shallow water, and they
suck gravel, sand, and mud to obtain the same substances ;
minute molluscs are also found in their stomachs. The latter
are provided with a strong gizzard like that of a bird, and the
intestine is very long and folded.

The spawn has not been studied in this country, but at
Naples Raffaele fertilised artificially the eggs of one species,
probably the thin-lipped mullet. They were of the free buoyant
kind, about 5; inch in breadth, and having a simple yolk with a
single oil globule. The larva was like that of other fishes with
buoyant eggs.

As mullet are so frequently found in brackish water, and can
be kept in fresh water, the question arises whether all of them
spawn in the sea. Concerning species which naturally live
in fresh water permanently, there is no doubt that they spawn
there, but with regard to brackish water forms like our own they
doubtless spawn in the sea, and there is no reliable evidence
that they can spawn and develop when confined in fresh water.

There are generally stated to be two British species, one in
which the upper lip is thin, and the other in which it is thick.
Certain other minute differences exist between them, but at
Plymouth all that I have seen belonged to the thick-lipped
species. Perhaps the other species is scarce.

pt FEPOT

THE GREY MULLET 335

The Thick-lipped Grey Mullet (J/ugi/ chelo).

There is no lateral line. It reaches sometimes 2 or even
3 feet in length. The colour is silvery-grey, with rows of dark
strokes along the sides.

These fish swim in shoals, and sometimes many thousands
are enclosed in a large seine at one time.

An advanced larva, believed to belong to this species, was
obtained from Mr. Dunn at Mevagissey, in May (Fig. 147).

oo)

It was 10°95 mm. long, or over 2 inch. The head and jaws
were well developed, but there were no fin-rays, except a few
commencing in the tail. The breast-fins were large and mem-

branous, and the primitive fin-membrane extended from the

Fic. 147.—Larva of Grey Mullet, a little more than 2 inch long, alive and magnified.

back round the hinder end of the body to the vent. Spawning
would therefore seem to commence at the end of April. I
obtained others a little more advanced in the middle of May, in
Cawsand Bay, Plymouth Sound.

In July and August the young mullet are abundant at the
surface off the mouth of Plymouth Sound. These are 2? inch to
an inch long. A number of them were reared in the aquarium,
being fed on finely-minced marine worms, which they took
freely off plates suspended in the water, but their growth was
slow: in August of the following year they were only 2} to
3 inches long. Whether this fairly represents the natural growth
in the sea there is no evidence to show, but I should think the
average size at one year of age would be somewhat greater
under the natural conditions.

THE. ANGLER FAMILY

THE fishes of this family, of which only the common angler
or fishing frog is British, have a very peculiar organisation.
They are without the great development of the tail and body
muscles by which the swimming powers usually expected in
a fish are produced, but have, on the other hand, a very great
development of the head, jaws, belly, and paired fins. But
these side-fins being used, not for swimming, but rather as flippers
for shuffling along the sea bottom, or for holding on to sea-
weeds or other objects, form blunt, fleshy limbs, not broad fan-
like paddles. The most characteristic feature is that the first
dorsal fin in these fishes is represented by a few long, separate
rays, the first of which is usually terminated by a flap of skin,
and this ray, which can be raised or lowered, is used as a lure
to attract other fish, which the anglers seize with their enormous
jaws. The capacious and elastic stomach doubtless indicates
that these fishes, like snakes, make a large meal at long
intervals, their mode of obtaining food necessarily implying
long periods of fasting. The gill-opening is small, and situated
below the base of the breast fin. The gills themselves are
reduced in number from the four usually present to three-and-a-
half, three, or even two-and-a-half. The bones at the base of
the breast fin are enlarged, and form a sort of arm ; the rays are
very short. The pelvic fins are placed on the throat in front of
the breast-fins, and have a similar structure. There is a second
dorsal and a ventral fin opposite to one another. The skin is
usually provided with projecting lappets or fringes which aid in
concealment, one chief necessity of these fishes.

Anglers are found all over the world, and are adapted to an
inactive life of concealment, in three different regions, namely
the shallow grounds near land, the deep sea, and the surface
of the ocean. In the latter case they are only found among

THE ANGLER FAMILY 337

floating sea-weed such as the Sargasso, to which they cling by
means of their arm-like fins. These forms are narrow from side
to side, while the others which live on the bottom are broad and
flattened from above downwards. Some of the deep-sea species
present a most remarkable peculiarity : at the end of the tentacle
on the snout instead of a flag-like membrane is a little fleshy
knob which contains a luminous organ, so that they fish with
an incandescent lamp as an attraction.

The Angler or Frog-fish (Lophius piscatorius).

Distinguishing Characters—Head large, broader than long ;
body short and tapering. Eye small. Mouth very wide, the
upper jaw shorter than the lower. Two rows of sharp teeth
in each jaw directed backwards and movable, a few on the
palate, none on the tongue. The first dorsal fin of six spines,
of which the first is on the snout, immediately behind the upper
jaw, and ends in a flag-like membrane. Ventral fin shorter
than the second dorsal. Numerous spines over the head, and
fringed lappets projecting from the skin all round the margin of
the body and on the tail. The colour is slaty-brown, witha net-
work of darker lines ; lower side white. The usual size’is from
2 to 3 feet in length, though specimens are occasionally taken
over 6 feet long. At Grimsby it is called the monk-fish, a name
which more properly belongs to RAznua sguatina, a fish of the
skate tribe.

Habitat.—The angler is found everywhere on the east side of
the Atlantic, from the Shetland Isles to the Mediterranean, and
on the west side from Newfoundland to Cape Hatteras. It is
abundant in the North Sea, and all round the British and Irish
coasts. At Grimsby the flesh of the sides is cut out and sent to
market, so that by the fishermen of that port the fish are always
brought in, and fetch a certain price.

frood.—A full account of the food and habits of the angler is
given in Day’s British Fishes (vol. i. p. 75). But there is one
sentence there which deserves to form the text for some addi-
tional remarks :—“ Its floating filaments kept in motion by
the tide decoy other fish, and the angler’s tendril is no sooner
touched than the game is caught.” Now, although the tentacle

Z

338 MARKETABLE BRITISH MARINE FISHES

of the fish naturally suggests a fisherman’s line with a bait on
the end, it is by no means certain that there is anything parti-
cularly attractive to other fishes in this tentacle or its membrane.
But, on the other hand, it is certain that the concealment of the
fish, on account of its colour and appearance, is very perfect ; it
cannot be distinguished from a boulder or a piece of rock with
bits of seaweed and other growths attached to it. Mr. Saville
Kent stated, from observations in the Brighton aquarium, that
when the angler saw fish in its neighbourhood it became excited
and agitated its tentacle, the “glittering piece of skin” at the
end of which served as a lure. I have seen nothing that could
be described as glittering in the appendage of the tentacle:
in the dead fish, at least, it is a thin flexible piece of skin of a
whitish or light-grey colour, dull and not glistening. At the
base there is a black spot on each side of the end of the stalk.
The membrane is divided at its further edge into two parts by a
deep cleft, and the edge of each part is slightly divided by
smaller clefts. The stalk is curved at its outer end, so that the
membrane hangs downwards. It is true that anything moving
in the water will attract the attention of fishes that hunt by sight.
But another and perhaps more important use of the tentacle is
indicated by some experiments made during the Irish Survey by
Mr. Lane, and mentioned in Mr. Holt’s Report (Scientific
Proc. Royal Dublin Society, vol. vii. part 4, p. 459). Mr. Lane
found that when he touched the top of the erected tentacle
with a stick the fish at once snapped with his jaws, so as to
catch exactly that part of the stick which had touched his
tentacle. This was repeated many times, until the fish was
exhausted. It is evident that this automatic and precise
mechanism of sensitive nerve and jaw-muscles must be most
effective in the capture of the angler’s prey. It is a spring-trap
of the most certain action, always set, and never betraying its
nature. Any fishes swimming near the ground are liable to
touch the tentacle of an angler, which cannot be distinguished
from the most innocent and insignificant frond of weed or stem
of zoophyte, and to touch it is certain and immediate death.
Breeding.—Day mentions that the eggs in a female 43 feet
long were computed to be nearly a million and a half, and
that the spawn, according to Baird, the founder of the United
States Fish Commission, was a floating sheet of mucus 60

THE ANGLER FAMILY 339

to 100 feet square. An excellent description with figures of
this spawn and of the young of the angler (larva) was given as
long ago as 1882 by Alexander Agassiz in America. Accord-
ing to this account the real dimensions of the sheet of spawn
were considerably less, namely, 2 to 3 feet in breadth and
from 25 to 30 feet long. The mucus was of a violet-grey
colour, and the black pigment of the larve gave it a blackish
appearance. The eggs were in a single layer. Agassiz found
the spawn in the latter part of August. In Scotland the spawn
sheets have been found: one stranded on the shore in July,
in the Firth of Forth, was 36 feet long and 10 inches wide.
Two other specimens were obtained in February.

At Plymouth a sheet of the spawn was received from Mr.
Dunn, of Mevagissey, on June 24th. According to his account
he saw it from the cliffs as a dark coloured patch in the water,
and next day took a boat, found it, and brought it ashore. It
was between 20 and 30 feet long and 18 inches wide. It was far
advanced in development, and the young fish being black could
be seen in it “like currants in a cake,” struggling to get out. A
large number of larve were hatched from this spawn in the
Plymouth aquarium, and some were preserved, but as I was absent
when the spawn arrived no very careful study was made of it.

Each egg inside its cavity is rather large, 1°75 mm. or ;7,
inch. The space between the egg and the envelope is also
rather large. It appears evident from the description and figures
of Agassiz that the sheet of spawn is simply formed by the outer
surface of the egg-membranes being jelly-like and sticky, so that
they become attached to one another before leaving the roe of
the mother. It will be easily understood that if the eggs of the
herring were to stick together in a singler layer, the membranes
remaining soft and pliable instead of being stiff, and the whole
layer were to float in the sea, we should have just the state of
things which we find in the spawn of the angler.

Dr. Fulton gives some observations on the roe of the fish as
taken from the female. He states that one taken from a fish
nearly 4 feet long, was 36 feet in length, 10 inches broad in the
centre, and 6 inches at the ends. The number of the eggs was
computed to be 1,345,000. The eggs were pear-shaped and
attached to the inner surface of the roe by the narrow end. It
would appear from these remarks, although they are not suffi-

fe

340 MARKETABLE BRITISH MARINE FISHES

ciently clear, that the roe forms a very long tube which is coiled
up inside the mother, and if we infer that the eggs are attached,
before they are quite ripe, by their stalks, we can understand how
they could become connected together by their sticky sides, and
so form the ribbon-shaped sheet of a single layer of eggs which
we know to be the condition in which they are shed into the
water. The existence of the stalks holding the eggs in the roe
until they have become attached together by their sides, explains
why they stick together in a single layer, and not ina mass. It

Fic. 148.—Three of the eggs of the Angler, from a sheet of the spawn, alive and
magnified ; after Agassiz.

is at any rate clear that the sheet of jelly containing the eggs is
simply formed of egg-membranes corresponding to those in
which other fish eggs are enclosed.

Each egg has a single large oil globule which, when the fish
develops, is situated at the hinder end of the yolk-sac: the yolk
is undivided.

It is characteristic of the larva, even before it leaves the egg,
that it develops a large amount of black pigment, although the
yolk and the substance of the body are quite transparent. The

‘UOTIPUOD SUIULUTMS AAT|OV S}I JO pua dy} SpIVMO} ‘asvIs aye, AIOA B JV JO[SUYy oy} Jo vaIeyT—'IST “OLY

“ZISSVOY Jaye § juoudoyaaop jo asejs layer S1apsuy ayy jo PAIeT— ‘OST “SI

‘zissesy aye $ payoyey APMoU AI[Suy oy} Jo vaAlw~y~— OVI “OT

ort

342 MARKETABLE BRITISH MARINE FISHES

larva when hatched is much more advanced in development than
those of most fishes with separate floating eggs. The mouth is
open, and the yolk much reduced. But a still more striking
peculiarity is that while there is as usual a transparent fin-mem-
brane along the middle line of the body and tail, there is on the
back just behind the head a short thick tentacle arising from a
protuberance of the body (Fig. 149). Thus early is the import-
ance of the tentacles formed by the dorsal fin-rays indicated.
The two pairs of side fins are present as mere skin-folds.
Very soon however, when the larva is a few days old, the pelvic
or throat-fins begin to lengthen into long tentacles. As the fish
crows in size, while the longitudinal fin membrane round the tail
region remains unaltered, the tentacle on the back of the head
crows larger, and also that of the throat-fin. Then a second
tentacle grows out behind the first on the back, and another in
the throat-fin (Fig. 150). The number on the back increases to
four, and in the throat-fin to three: they become very long,
especially the latter. Now the bony rays of the second dorsal
fin and of the ventral and tail fin appear, while the filaments of
the throat-fin grow so much that the first is more than twice as
long as the body of the fish, and the second reaches to the end
of the tail. The breast fin is a large fan-shaped paddle with a
circular edge. The fish all this time swims freely near the sur-
face or in the open water, not resting on the bottom, and in
accordance with this fact the body is as yet narrow from side to
side and deep from the back to the belly. The front dorsal
tentacles are also long, and it turns out that those first developed
are the five hinder ones, the first, which in the adult is shorter
than the second, developing last in front of the others. A later
free-swimming stage is figured by Dr. Giinther in his /utroduc-
tion to the Study of Fishes, in which the rays of the throat-fin are
somewhat shorter, but still projecting beyond the membrane of
the fin, the rays of the enormous breast-fins also project, and the
rays or tentacles on the back of the head are furnished with little
branched flaps of skin on their sides, except the first which has a
forked flap at the end very like that of the adult fish. In this
stage the fringed flaps round the edge of the lower jaw have also
appeared, the body is broader and flatter, and it is evident that
the young fish is gradually passing into the condition of the
fully developed angler.

Mie, BLENNIES

THESE are fishes with soft slimy skins, in which the scales are
very rudimentary or altogether absent. The dorsal fins occupy
the greater part of the length of the back, and’ may be con-
tinuous from end to end, and also with the tail-fin, or may be
partially divided into two or three distinct fins. The vent is
usually a little in front of the middle of the body, and the ventral
fin extends from thence to the base of the tail fin, or is continued
into the tail fin. The breast fins are rounded and large, the
throat fins either small and placed in front of the breast fins, or
absent altogether.

Blennies belong especially to the shore, lurking about in
crevices of rocks, or between and under stones, or among sea-
weed, and are commonly found between tide-marks. They are
spread generally along the temperate and tropical coasts. The
sea-cats or cat-fishes are different from the majority of the
family, being of large size, and living in rather deep water. The
eggs of the blennies, if deposited at all, are, so far as is known
without exception of the fixed attached kind, adhering together
in masses, and undergoing development on the ground. But
the viviparous blenny brings forth its young alive.

The British members of the family are :—

I. Species in which the dorsal fin is imperfectly divided
into two, and separate from the tail fin; no scales; pelvic fins
present.

I. The Common Blenny or Shanny.—Head smooth,
without any appendages; notch between the two
divisions of the dorsal fin very slight.

2. The Gattorugine.—A fringed, fleshy tentacle above
each eye.

344 MARKETABLE BRITISH MARINE FISHES

3. The Butterfly Blenny.—Front part of the dorsal fin
elevated, and having a deep black spot, surrounded by a
white ring.

4. Montague’s Blenny.— Having a fold of skin between
the eyes, fringed with small tentacles.

II. Species without any division in the dorsal fin; caudal
separate ; throat-fins very small ; small scales present ; two pairs
of tentacles on head.

5. Yarrell’s Blenny.

III. Species in which the body is elongated with a single low
dorsal fin, and the tail-fin not separate.
6. The Gunnel or Butter-fish.—Body long and slender ;
a row of black spots with a white ring round each along
the base of the dorsal fin on each side.
7. The Viviparous Blenny.—Body tapering towards the
tip of the tail, and a long notch in the edge of the dorsal
fin at the tail end.

IV. Species of large size, with tail small and separate; no
throat-fins ; scales rudimentary.
8. The Sea-cat, Wolf-fish, or Cat-fish.

At St. Andrews Mr. Holt saw the spawning of the butter-fish
or gunnel in the aquarium in February. The eggs were adhesive,
and the parents were seen to roll the mass of eggs into a ball by
coiling their bodies round them, not both parents together, but
the male and female in turns. It has been observed by Professor
McIntosh and Mr. Anderson Smith that in the natural condition
the parents are found coiled round the balls of spawn, which
are somewhat larger than walnuts, and not attached to anything.
The spawn is shed from the middle of February to April.

The blennies proper all attach their eggs in a single layer over
the sides of cavities between stones or in rocks, but it has not
been observed with certainty whether it is the male or the
female that guards and tends them. A large hollow bone,
probably from the leg of an ox, on the sides of the cavity
of which were attached the eggs of the butterfly blenny, was
examined by me at Plymouth. A specimen of the fish was
found in the cavity, and it was probably the male, but I did

THE BLENNIES 345

not note the sex. The yolk was of an orange-red colour, and
quite impervious to light.

In the Firth of Forth specimens of the viviparous blenny in
which the young were ready to be born, were found in February
and March between tide-marks. The number of young is from
50 to more than 100. Each is about 1% inches long, and
in all respects like its parent, all the development and trans-
formations taking place within the roe: the two roes are united
forming a single sac.

The Cat-fish or Sea-cat (dAvarrhichas lupus).

Distinguishing Characters —In the cat-fish the tail is small but
distinct, and the rays of the dorsal fin diminish in length at the
hinder end to the base of the tail-fin, while those of the ventral
do not. The chief peculiarity is the character of the teeth: in
the front of each jaw are a group of long curved canine teeth or
fangs ; in the lower jaw behind there is a double row of rounded
grinding teeth on each side ; in the roof of the mouth are three
double rows, those in the centre flat, at the sides pointed. The
colour is a bluish-grey, witha row of black bands passing straight
from the back more than half-way down the sides. It reaches
6 feet in length.

It is a northern fish, extending from Iceland and Greenland
to the North Sea on the European side, and to Cape Hatteras
on the American. In the North Sea it is not usually found
south of the Dogger Bank, and is more common at depths over
30 fathoms. By means of its powerful teeth it is able to crush the
hardest shells, such as that of the whelk, and it feeds upon shell
fish, sea-urchins, and crustacea.

The eggs of the cat-fish (Fig. 152) are very large compared
with buoyant eggs, and are shed in the winter months. The
single egg is about 6 mm. in breadth, or more, that is nearly
t+ inch. Like those of the small blennies, the eggs are adhesive,
and are attached to one another in a large mass, which is
deposited on the sea-bottom in deep water. Whether the male
or either parent takes care of the eggs there is no evidence
te show: we car cnly consider from analogy that he probably
does. A mass of the eggs was received alive, and in good

346 MARKETABLE BRITISH MARINE FISHES

condition by Professor McIntosh, at St. Andrews, in January,
1886. These were in an advanced stage of development, and
many of the larve hatched out during the four or five days after
they were received.

The length of the hatched larva (Fig. 153) is 11 or 12 mm.
or nearly 4 inch. The body is transparent and slender, and
surrounded in the middle line behind by a narrow fin-membrane.
The yolk-sac is very large in proportion, and is longer from its
attachment downwards than in the direction of the length of
the fish ; it is attached therefore by a rather narrow base. In
the middle of its front surface is a large single oil globule. The
yolk is straw-coloured and somewhat transparent, and on its
surface is a network of blood-vessels. There is some pigment
in the eyes and on the back of the head, but scarcely any else-
where. The mouth is open, but small. Some of these larve,

Fic. 152.—Eggs of the Cat-fish, natural size ; after McIntosh.

hatched at the end of January, lived in the St. Andrews
laboratory until May 14th, by which time the yolk was all
absorbed, the jaws and teeth well developed, and delicate fin-
rays had appeared in the longitudinal fins and tail-fin (Fig. 154).
The eye was relatively much larger than in the adult. The
shape was that of the full-grown fish, and the colour was a dark
smoky-brown except on the belly. The fish had not grown
greatly in length: the exact measurement is not given, but from
the figure it appears to have been about 2 inch. It is interesting
to note that the absorption of the yolk which in the case of a
larva like that of the plaice, occupies about a week, lasted in the
cat-fish three months and a half, and also that while in the plaice
the larva has to feed itself for about two months before it has
completed its development and reached the perfect condition,
in the cat-fish the development of the skeleton and all the

347

THE BLENNIES

‘ysojUpo Taye ¢ payruseu ‘ysy-je

J ay} Jo varey poyoyey A[MON— “EST “OI

348 MARKETABLE BRITISH MARINE FISHES

, just

Ms CL
. ——
a — /

1 months old

y, about 3

SARA

a
C\

Lets
inch long, reared in the St. Andrews Laborator

after the absorption of the yolk ; after Prince.

38
oD

Young living Cat-fish 2

154.

Fic.

characters of the perfect fish are nearly complete by the time
that the yolk is all exhausted.

At St. Andrews specimens of the cat-fish 62 to 8} inches
long were obtained in July and August, and must have been a
year old.

THEY SUCKER RAMILY

THIS family includes only fishes with a sucker on the belly,
which are found in the arctic and temperate regions of the
northern hemisphere. There are no ordinary scales ; the skin is
either entirely unarmed or provided with scattered rough bony
tubercles. There are two dorsal fins or only one. The throat-
fins, in front of the breast-fins, form the sucker ; the fin-rays are
short and spread out round a shallow pit, and outside them is a
ring of skin; the sucking action is produced simply by the
contraction of the muscles in the centre. These fishes live on
the shore, and up to a certain moderate depth. They have no
air-bladder.

The eggs are comparatively large and adhesive, deposited in
clumps or masses, and the male parent guards them.

The Lump-sucker (Cyclopterus lumpus).

Distinguishing Characters—The massive shape, marked with
longitudinal ridges and rough tubercles are characteristic of this
fish. The first dorsal fin is entirely buried in a fleshy ridge in
the back, the edge of which is armed with a row of tubercles.
The second dorsal and the ventral are of the usual structure,
and opposite to one another. The stalk of the tail is short. The
breast-fin is large, and the sucker large and powerful. There
are three rows of large tubercles on each side, besides numerous
minute ones all over the skin.

The southern limit of the lump-sucker is the Bay of Biscay ;
northward it extends to Iceland, Greenland, and the north coast
of Russia. On the American coast it extends southward to

350 MARKETABLE BRITISH MARINE FISHES

Cape Hatteras. It is much more common on the coasts of
Scotland than on those of England or Ireland.

Breeding.—The two sexes differ in size and colour, the
female being large and dull coloured, generally of a uniform
blue, yellowish-white beneath. The male is smaller and, with
some blue on the back, has its sides and belly of a brilliant red
and yellow. In Scotland the male is called the “ cock-paidle,”
the female the “hen-paidle.” The exact reason why the fish is
called a paddle I do not know.

Dr. Fulton found that in fish 173 to 182 inches long the number
of ova was from 79,000 to 136,000. Spawning takes place in
March, April, and May, and the whole of the eggs seem to be
shed at one time in one mass. There are, however, holes in the
mass to allow the water access to the interior. The spawn is

Fic. 155.—Young Lump-sucker ? inch long ; after Agassiz.

attached to rocks or piles, and is as often as not more or less
exposed at low water in spring tides. The male always remains
ceuarding the eggs and keeping the water moving over them by
the action of his breast fins. The colour of the eggs varies from
red to pale-yellow or nearly white. Individually the eggs are
large, measuring 2° mm. in breadth or over 4, inch. The
yolk is but slightly transparent, and contains numerous oil
globules of various sizes. The egg membrane is thick and firm,
and neighbouring eggs only stick together over small areas of
the surface.

The little fish when first hatched is not quite + inch long.
The development is far advanced, the body coloured green and
opaque, the mouth and jaws well developed, the sucker already

formed, and the breast-fins have fin-rays. The central fin-

THE SUCKER FAMILY 351

membrane round the tail-end of the body is present, but it has
primitive fin-rays. There are, however, no tubercles in the skin,
the surface is smooth, and the shape more like that of a tad-
pole than of the parent fish.

The young at somewhat later stages are abundant among
weeds on the shore, and are also frequently taken at considerable
distances at sea, adhering to detached floating pieces of sea-
weed. Fig. 155 shows the appearance of a specimen 2 inch
long.

The Diminutive Suckers (L7paris vulgaris and Liparis
Montagut).

It is not necessary for the purpose of the present work to dis-
tinguish between these two kinds. They are sometimes called
sea-snails. They have a soft, movable skin without scales or
tubercles. The sucker is very similar in structure to that of the
lump-sucker, but there is only one undivided dorsal fin, the rays
of which are of uniform, very moderate length. The ventral fin
is similar ; both extend to the root of the small tail-fin. The
head and body are smooth and rounded, the tail tapering and
flattened from side to side. The colours are brown or yellowish-
brown with lines or spots. The greatest length of these fish is
not more than 6 inches.

Like the lump-sucker they range to the arctic regions. They
haunt the shore, and are usually common in estuaries. In
relation to fishes of commercial value their only importance is
that their spawn has been frequently mistaken by naturalists as
well as by fishermen for the spawn of the herring. The spawn
forms little rounded masses of eggs attached to one another,
and fastened to zoophytes or red sea-weed. It is usually found
on one particular zoophyte called Hydrallmannia. The mass
is about as big as a marble or larger. Individually the eggs are
very similar in size to those of the herring, but a little smaller,
namely, 1°27 mm. or j45 inch in breadth. But the mass of eggs
can be usually distinguished from a clump of herring spawn by its
more compact rounded shape, the masses of herring eggs being
more irregular. Herring spawn is also more transparent and
delicate looking, the membranes enclosing the eggs being

352 MARKETABLE BRITISH MARINE FISHES

thinner. With the aid of the microscope there is no difficulty
in distinguishing the spawn of the suckers, for in these eggs the
yolk is transparent, and contains a number of oil globules.

Ke
THAN SURUUBANAN TOTS
LZ
Lif

Fic. 156.—Newly hatched larva of the Diminutive Sucker or Sea-snail.

The hatched larva of the sucker (Fig. 156) is as different as
possible from that of the herring, the head and body being
plumper, and the vent placed near the head, instead of near
the end of the tail as in the herring.

AEP ENDICES

A

A

dvdlevbcle IND Xe 1

VIVIPAROUS FISHES

Tue fact that in certain species among cartilaginious fishes (z.e., sharks
and rays) the whole development of the egg takes place within the body
of the mother, has been mentioned in the text. In these cases there is
a quantity of yolk in the egg, as in cases in which the eggs are laid, and
when the embryo is advanced in development the yolk is contained in a
globular bag or umbilical vesicle, attached to the embryo by a stalk. In
many species of sharks there is no attachment or connection between
the oviduct in which the embryo is contained, and the embryo or yolk-
sac. But in these cases the inner surface of the oviduct is furnished
with finger-like processes, called villi, and these secrete a nutritious liquid
which aids to some extent in the nourishment of the embryo, ‘This is
the case in the spur-dogfish and others. In several other sharks, includ-
ing the large ferocious species of tropical seas, the yolk-sac, when the
yolk is nearly consumed, becomes attached to a certain area of the inner
surface of the egg-tube or oviduct, and the blood-vessels of the yolk-sac-
belonging to the embryo come into close proximity with the blood-
vessels of the adjoining surface of the oviduct. Projections and depres-
sions are formed on the two surfaces or membranes, maternal and
embryonic, and the blood-vessels of the yolk-sac take up nourishment
and oxygen from the blood-vessels of the oviduct. This condition forms
what is called a p/acenta, very similar to that which is formed in the
gestation of #ammad/s, or animals which have hair and which give milk.

The smooth hound (Mvustelus vulgaris) of British seas has no pla-
centa, the yolk-sac remaining always free and separate from the walls
of the oviduct but in a closely allied species (AZustelus evis) occurring
in the Mediterranean, a well-developed yolk-sac placenta is formed. In
the latter case the egg is at first surrounded by a thin flexible egg-shell,
between which and the egg proper there is a wide space filled with

TNs ae

356 MARKETABLE BRITISH MARINE FISHES

liquid or “white.” The egg-shell remains even when the placenta is
formed. There are often three or four embryos in each oviduct, each
embryo having its own placenta.

No placenta has been discovered in any family of rays, but on the
other hand the amount of nourishment supplied to the embryo in the
viviparous forms by the secretion of the walls of the oviduct is very
great. ‘The gestation of several of the sting-rays and eagle-rays (Z7y-
gonide and Myliobatide) of the Indian Ocean has recently been particu-
larly investigated by Professor Wood-Mason and Surgeon A. Alcock in
specimens obtained by the Indian Marine Survey steamer /vestigator.
In Zrvgon Bleekert the villi were found uniformly scattered over the
surface of the walls of the uterus or dilated oviduct. One specimen
examined was 3 feet across the pectoral fins, and contained an embryo
8 inches across. As there were no special organs for the absorption of
the uterine milk, as the secretion may be called, it was concluded that
it was taken through the mouth or spiracles and digested in the stomach.
This conclusion was confirmed by the very curious arrangement dis-
covered in another species of sting-ray called P/evoplate@a micrura. In
this case the villi were confined to the part of the uterus near the
spiracles of the foetus, and a bundle of very long villi actually passed
through each spiracle into the throat of the foetus, as seen in Fig. 157.
The spiracles were very large. These villi thus pour a nutritive secretion
into the throat of the foetus, much as the teat of a mammal pours out
milk, but without any sucking action on the part of the fcetus. In
these cases the young, when ready for birth, is much larger and heavier
than the egg from which it arose.

Many species of bony fishes also bring forth their young alive,
and in a fully developed condition, although this mode of propagation
is not exhibited by any of the commercially valuable species inhabiting
British seas. One small marine fish which is common on British shores
is viviparous, namely the viviparous blenny (Zoarces viviparus), and
there is only one other marine species occurring in Europe which has this
peculiarity, namely the so-called Norway haddock, Sebastes norvegicus.
These two belong to quite distinct families, the former to that of the
blennies, the latter to the Scorpzenidze, and there is no close similarity
between them in structure and habits. Zoarces is an elongated eel-like
form without scales, with short and flexible fin-rays, and with rudimentary
pelvic fins, while Seéas¢es is a much larger fish, of narrow compact shape
and with strong spines and scales. Zvarces haunts the shore and lurks
under stones, while Seéas¢es lives in deeper water and swims about
boldly. Both, however, are northern species, the Norway haddock
extending from Spitzbergen to the south-west coast of Norway, but
having rarely been taken on the more northern coasts of Britain, while

APPENDIX I 287

the viviparous blenny is common on the east coast of Britain, in the
Baltic, and along the shores of Scandinavia, but is very seldom found on
the south coast of England or the west coasts of Ireland and Scotland.
Other species of these families living in other parts of the world are also
viviparous : on the Pacific coast of North America no less than fifty-one
species of Scorpzenidze occur which produce living young. ‘This coast
is remarkable above all other parts of the world for the extraordinary
number of viviparous species among the fishes which live upon it. In

>

Fic. 157.—Fcetus of an Indian Sting-ray (P¢evop/atea) as seen when the uterus is cut
open along its dorsal side, the uterine filaments or villi passing on each side into
the wide spiracles of the foetus. (After Wood-Mason and Alcock.) A, villi on
inner surface of oviduct ; B, longer villi passing into the spiracle ; C, end of the
left pectoral fin which is rolled round the body,

addition to the Scorpzenidz there are a number of species forming the
family Embiotocide, which is confined to the North Pacific Ocean,
These fishes live near the shore, and closely resemble the wrasses in
habits, appearance, and structure, most of them being brilliantly
coloured.

Another family of bony fishes 1n which viviparous reproduction
takes place is that of the Cyprinodontide, which are mostly fresh-
water fishes closely similar to the carps. Cyprinodontidz signifies

358 MARKETABLE BRITISH MARINE FISHES

toothed carps, these fishes having teeth in the jaws, while the jaws of the
carps are toothless. They are fishes of quite small size, and occur in
south Europe, and in the warmer parts of the American continents.

The fact that viviparous reproduction, or the internal development
of the eggs, is found to occur in several widely distinct families, shows
that its origin is due to circumstances which may affect any family of
fishes without reference to its relationship with other families in structure
and descent. What these circumstances are it is difficult to say. We
have good reason to believe that viviparous reproduction, in whatever
division of the animal kingdom it is evolved, is always a secondary
modification ; that at first eggs were always expelled from the body of
the mother to undergo their development, and that in certain cases the
expulsion is delayed so that development goes on in the ovary or in the
egg-tube. Internal fertilisation must necessarily precede internal develop-
ment of the ova, for the eggs cannot begin to develop until they are
fertilised. We know that the arrangement of the roes in the bony fishes
was in existence before internal fertilisation or internal development
occurred. We know that in certain species, as has been mentioned in
the text, the males have developed a very definite interest in the female
and the eggs. There is evident in these cases an association
between the perception of the female and her eggs, and the expulsion of
the milt. It is not difficult to understand how this association might be
so developed that the milt in certain species came to be introduced into.
the ovary, and so the eggs were fertilised internally.

In animals in which internal fertilisation takes place the milt is
usually injected by some kind of intromittent organ acting as a penis,
and in viviparous bony fishes we find some such organ present in the
males. In the viviparous blenny it is merely an elongated papilla on
which the testicular canals open. In some Cyprinodonts there is in the
male a tube passing down the front edge of the ventral fin, and the milt
passes through this tube. The ventral fin is elongated, and with the
tube forms an intromittent organ. In the females of these species the
opening of the oviducts is covered by a special scale, which is free on
one side but not on the other. The male organ in some individuals is
turned to the right, in others to the left, and in some females the opening
beneath the special scale is to the nght, in others to the left. Copula-
tion thus takes place sideways, a left-sided male pairing with a right-sided
female, and vice versa.

In the viviparous blenny copulation and fertilisation take place in
September. The eggs during their formation, or growth to the ripe
condition, are contained, as in all bony fishes, in chambers in the
ovarian substance, which chambers are called follicles. | Whether
fertilisation occurs before the eggs have left the follicles is not stated,

APPENDIX I 359

but they certainly leave the follicles and lie free in the cavity of the
ovary at a very early stage of development. Like the eggs of species
which are not viviparous, the eggs of Zoarces are contained in a spherical
egg-membrane, which when the development of the embryo has reached
a certain stage bursts, and sets the developing fish free in the ovarian
cavity. The eggs are thus hatched in the interior of the ovary, whereas
in other cases they are hatched in the sea after they have been expelled
from the parent fish. It has been estimated that this hatching takes
place about twenty days after fertilisation. After hatching the larve
remain in the cavity of the ovary for a considerable time, and go through
the whole of their further development and transformation in this situa-
tion. ‘The young, in fact, are not born until about four months after
fertilisation. In the Firth of Forth females in which the young were on
the point of escaping were observed in February and March. The
newly born young are about’ 1} inch long, and in all respects similar
to the parent in structure. It is thus clear that either a larger quantity
of yolk in the egg or some other supply of food must be available for the
larvee in the ovary of Zoarces to enable them to develop to this size and
condition, considering the imperfect condition of free fish-larvee at the
moment when the yolk is all consumed. The explanation is that the
quantity of yolk is not large, but that the larvee are nourished also by an
albuminous liquid formed in the interior of the ovary as a secretion
from its walls. ‘The number of young produced at a birth varies very
much in different females, and depends chiefly on the size of the latter.
Females of 7 or 8 inches in length are found to contain from 20 to 40
young, those of 8 to 10 inches from 50 to 150, while larger specimens
have been found to contain 300 young or even more. Some specimens
have been found in the gravid condition in summer and autumn, so that
there is reason to conclude that fertilisation takes place in some cases in
spring and birth in autumn, though it is by no means proved that the
same female breeds twice in a year.

In Fig. 158 is shown the appearance of the developing egg of the
viviparous blenny before hatching, taken from the ovary on September
28th ; it is magnified 12 times. Fig. 159 represents one of the young
nearly ready for birth, taken from the ovary on November 24th. The
little projection on the ventral surface beneath the pectoral fins is the
remains of the yolk-sac. The figure represents the young fish magnified
to twice its length. The little circle below represents the actual size of
the egg, and the line the actual length of the young fish at the stage
mentioned. The process of development and gestation in other vivip-
arous fishes is by no means exactly or closely similar to that which is
observed in the viviparous blenny. Great differences are found to exist
in the degree to which the nourishment of the embryo is derived from

360. MARKETABLE BRITISH MARINE FISHES

the yolk of the egg or from nutritious secretions of the ovary. The two
sources of nourishment often exist together, but generally the more
abundant one is, the more diminished is the other, either being capable
of supplying the place of the other. We may consider those cases in
which the nourishment is derived chiefly from the yolk as being more
primitive. Cases of this kind occur among the Cyprinodonts, for
instance in the species of Gamdbusia.

Gambusia patruelis is a species living in the fresh waters of Virginia.
The adult males are only 1 inch long, the females 12 inch. The
ventral (so-called anal) fin has the anterior rays elongated to form an
intromittent organ, but there is no tube running down these rays. In
copulation the male has been observed to have his head turned towards
the tail of the female, and to insert the end of the prolonged ventral fin
into the opening of the ovary. ‘The ovaries of the two sides are united

Fic. 158:

Fic. 158.—Developing Egg of the Viviparous Blenny taken from the ovary Sept. 28th.
Magnified 12 times. Fig. 159, Young of the Viviparous Blenny, taken from the
ovary of the mother on Nov. 24th; magnified twice. The circle and straight
line show the actual size of the egg and length of the unborn young fish. (After
Rathke. )

into one, and at each gestation twenty to twenty-five yellowish eggs each
about 34; inch in diameter are produced. These eggs do not leave the
follicles in which they are formed, but an opening is formed at the
outer part of the follicle ; through this opening sperms enter and fertilise
the egg, which goes on developing in the follicle. It is very remarkable
that in this case the ovary has lost its tubular or sac-like character, and
the germinal tissue is exposed in the general body-cavity, the young
escaping at birth by an abdominal pore. Another peculiarity is that
the egg does not appear to be provided with an egg-membrane, a struc-
ture which is unnecessary in an egg that develops within the follicle in
which it is produced. ‘The walls of the follicle are richly supplied with
blood-vessels, and by this means the developing fish is provided with
oxygen ; but although the follicle contains liquid around the embryo
this does not appear to contribute to the nourishment of the latter, for
the yolk is not exhausted until the, young fish is completely developed

APPENDIX I 261

and ready for birth. When the young fish is born its fins and fin-rays
are completely developed, and it resembles its parent in everything
except size.

In the curious Axableps, a Cyprinodont of Guiana and Brazil, which
is distinguished by the interesting peculiarity that the upper half of its
eye is formed to see in the air, and the lower half to see in the water,
the yolk is soon exhausted, and the nourishment of the embryo during
the greater part of gestation is provided by the nutritious albuminous
liquid secreted by the walls of the follicle. This liquid is absorbed by
papilla on the walls of the yolk-sac, which remains and enlarges after
the yolk has all been absorbed. The papille are situated along the
course of the veins of this abdominal sac, and the nourishment they
absorb is thus taken up by the blood, and so supplies material for the
growth and development of the embryo.

In the Embiotocidz of the Pacific coast, which appear to be known
in California as ‘“surf-perches,” the two ovaries in the female are united,
forming a single closed sac, the germinal folds in which the eggs are
produced depending lengthwise from the dorsal wall of the cavity and so
partially dividing it into several compartments. The embryos undergo
their development outside the follicles in which the eggs are produced,
lying between the folds of germinal tissue, which are abundantly
supplied with blood-vessels. There is very little yolk, and consequently
the embryos are nourished by a secretion of the walls of the ovary. At
an early stage, it is stated, the remains of the milt introduced into the
ovary in copulation are swallowed by the embryos. In later stages the
hinder part of the intestine is much enlarged and its inner surface is
provided with long processes (villi). ‘The ovarian secretion appears to
be swallowed by the embryo and absorbed by these villi of the dilated
hind-gut. Another peculiarity in these embryos is that the median fins
(dorsal, ventral, and tail-fin) are much developed, and their membranes
between the fin-rays are produced into thin delicate processes. Both
the fins and these processes are richly supplied with small blood-vessels,
and act the part of gills during the period of gestation, their function
being to absorb oxygen from the blood in the ovarian folds with which
they are in contact. This arrangement approaches somewhat to that
which exists in the placenta of mammals, but the relation of the embry-
onic structures to the maternal is much less intimate than in the latter,
and the function of the vascular membrane appears to be only respir-
atory, not nutritive.

In the Embiotocide the eggs are fertilised in the follicles in which
they are produced, but escape from these soon afterwards to develop in
the ovarian cavity. The ovary frequently contains forty or fifty young
fish, which at birth measure 2 inches or more in length.

362 MARKETABLE BRITISH MARINE FISHES

The gestation of the Scorpzenidze does not appear to have been
completely investigated, but it has been found that in gravid specimens
of the Norway haddock the embryos are small and very numerous ; the
number in a single fish was estimated at fully a thousand. At a certain
stage which has been described, the individual embryos were slender
and small, not quite 4 inch in length. The yolk-sac was large in
proportion, and some embryos were enclosed in an egg-membrane,
while others had hatched. ‘The embryos were situated in the spaces
between folds and processes of the germinal tissue of the ovary ; these
processes were highly vascular, and doubtless served for the respiration
of the embryos, that 1s to say, the latter derived from the blood in them
the oxygen necessary for their existence.

ee NIOLX il

THE, PISHING GROUNDS

(See Maps: “ Fishing Grounds of the British Islands” and “West
Coast of Europe.”)

THE area exploited by the fishermen of the British Islands extends
to Iceland on the north, and to the coast of Spain and Portugal on the
south, while to the westward it is limited by the deep basin of the
Atlantic. Drift-net fishing in the open sea is unaffected by the depth of
the water or the nature of the bottom, and the distance from the coast
to which it is extended depends, therefore, on the presence of the fish
in sufficient abundance, and the demand or markets that can be
supplied. In line and trawl fishing, on the other hand, the depth and
character of the bottom are of great importance.

The 1oo-fathom line passes outside the British Islands, bounding a
plateau on which all these islands, including the Hebrides, the Shet-
lands, and the Orkneys, are situated. But the Faroe Islands and
Rockall lie beyond it. This line runs parallel to the coast of Portugal
and Spain at a very short distance off, along the west coast of France it
begins to diverge farther from the land ; it passes outside the entrances
of the English Channel and St. George’s Channel at a considerable
distance, and then runs along the west of Ireland and the Hebrides.
Passing to the east, round the north of the Shetland Isles, it ap-
proaches the coast of Norway, and then bends round to the south-east,
bounding a deep channel which runs close to the southern coast of
Norway into the Skager Rack. Around the coast of Iceland and the
Faroe Islands the 100-fathom line is nowhere at a great distance, so that
the extent of shallow water is confined within narrow limits on the shores
of these islands. Beyond the 1oo-fathom line the slope of the bottom 1s
everywhere rather rapid, descending on the west to the basin of the
Atlantic, on the north to that of the Arctic Ocean.

364 MARKETABLE BRITISH MARINE FISHES

The 50-fathom line on the whole follows more closely the contour of
the actual coast line. It sends a pointed tongue into the entrance of
the English Channel, runs round the outside of the Scilly Islands, and
then forms a narrow channel between England and Ireland, but nearer
to the coast of the latter. It runs at no great distance from the south
and west coasts of Ireland, bounds a channel between the Outer
Hebrides and Scotland, as well as numerous depressions in the firths
and channels on the west coast of Scotland, runs northwards so as
to pass round the outside of the Shetlands, and then passes down the
east coast of Scotland in an irregular line. At about the latitude of the
Farn Islands the 50-fathom line turns to the east, and at the second
degree of east longitude runs north again to reach the edge of the
Norwegian depression previously mentioned. ‘Thus to the east of Scot-
land and the Orkney and Shetland Islands there is a depression of
depths between 50 and 100 fathoms, while to the south and east of this
depression the depth is nowhere over 50 fathoms except in one or
two isolated pits: this shallow area includes the whole of the English
Channel.

To the east of the depression, opposite the west coast of Jutland, lies
-the Great Fisher Bank, bounded by the 4o-fathom line to the north and
west, but outside the 30-fathom line. Lying obliquely across the broadest
part of the North Sea south of the Great Fisher Bank is the Dogger
Bank, bounded by the 20-fathom line all round, and rising at its south-
west corner to within ro, 9, and even 7 fathoms of the surface. South
of the Dogger Bank is a narrow depression descending to 50 fathoms at
its deepest part, but limited in extent. This is the Great or Outer
Silver Pit. Along the shores of Holland and Germany the 20-fathom
line is thirty, forty, and even fifty miles from the lines of islands,
Frisian and North Frisian Islands, which fringe these shores.. These
shallow grounds are what the trawlers of Hull and Grimsby call the
Eastern Grounds. Between the 20-fathom line and the Dogger Bank
the depth is.greater, but does not exceed 30 fathoms.

The 20-fathom line to the north of Holland passes right across the
North Sea to the English coast, bounding the Silver Pit on the south.
South of this line the greater part of the North Sea as far as the Straits
of Dover is less than 20 fathoms in depth. There are, however, isolated
depressions here and there. Narrow small pits occur off the mouth of
the Humber, called by the fishermen Little Silver Pit, Sole Pit, and Coal
Pit. Off the coast of Norfolk are a number of banks and shoals in the
form of narrow ridges, mostly lying between north-west and south-east.
Further south off the east coast of Norfolk and Suffolk, and running
parallel to that coast there is a depression descending in some places to
30 fathoms. To the east of this depression there are a number of

APPENDIX II 365

narrow ridges running north and south, and rising to 11 or 12 fathoms
from the surface. One of these 1s marked on the chart as the Brown
Ridge, and they may be called the Brown Ridges.

The drift-net fisheries are prosecuted on the largest scale by Scotch
boats, Yarmouth and Lowestoft boats, and boats belonging to Mount’s
Bay and Plymouth. ‘There are drift-net boats at a very large number of
ports all round the coast, but those of the districts mentioned carry on
the fishing in the regions where it is most productive, not merely in the
neighbourhood of their own ports. The principal herring fishery is that
carried on in spring, summer, and autumn, on the north and east of
Scotland, and off the east coast of England. A considerable number of
English, Scotch, and Manx boats also take part in the herring fishery
off the east coast of Ireland. Mackerel fishing is principally carried on
off the south coast of Ireland, Mounts Bay, and the coast of Devon and
Cornwall in the earlier months of the year, and a large number of boats
from Lowestoft resort thither to take part in it. In September and
October as well as in May and June Lowestoft boats fish mackerel off
their own coast. The pilchard fishery is carried on entirely by Devon
and Cornish boats off the south-west coast of England.

Trawling is extensively carried on within the 50-fathom line off the
south coast of Cornwall and in the Bristol Channel. Large numbers of
sailing trawlers belonging to Plymouth and Brixham use these grounds.
The Mounts Bay grounds are visited chiefly in spring and summer, and
the same is true of the grounds off the north coast of Cornwall. These
grounds yield soles, turbot, brill, lemon dabs, plaice, hake, skates, and
rays, John dories, tubs, sea bream, and other southern species, but
haddocks are only occasionally taken and cod are not plentiful.

The eastern part of the Channel is less important as a trawling
ground. ‘The southern part of the North Sea is worked chiefly by sail-
ing vessels belonging to Lowestoft and Ramsgate. These grounds
resemble in their produce the grounds of the Channel, and differ con-
siderably from the more northern and deeper parts of the North Sea.
Cod and haddock are scarce; plaice are fairly plentiful, but small, the
majority from 11 to 13 inches long, and the majority at the latter length
mature ; soles are fairly plentiful, turbot and brill not uncommon ; lemon
dabs are scarce ; common dabs and whiting are abundant, grey gurnard
are plentiful, and also tubs or latchets; weevers, the larger and the
smaller species are very abundant on the Brown Ridges ; rays and skate
are fairly plentiful.

In the northern part of the North Sea, excluding the Eastern
Grounds, the staple produce of the trawl always consists of haddock
and plaice. Without these two kinds of fish, especially the former, the
enormous fleets of steam-trawlers which now range these waters could

366 MARKETABLE BRITISH MARINE FISHES

not be kept at work at all. One hundred and fifty to two hundred boxes
of haddocks are often landed at Grimsby by a steam-trawler after a
week’s fishing or even less on the Dogger Bank. Plaice are also fairly
abundant on the Dogger, and some cod are taken, especially in spring.
A few turbot are taken but soles are scarce. Lemon dabs are seldom
taken on the Dogger, but are found in depths beyond 20 fathoms
throughout the northern part of the North Sea.

The Eastern Grounds are worked by English vessels, mostly from
Grimsby and Hull, in summer, from March and April onwards. They
are less productive in winter. They are remarkable for the great
abundance of small plaice taken on them, more than 250 boxes being
often landed from a single voyage by a steam-trawler. Soles, turbot,
and brill are also plentiful on these grounds, the soles being mostly
large, but a large proportion of the turbot and brill small. Cod are
scarce, lemon dabs absent, and haddock occur in very moderat
numbers. Latchets or tubs are rather plentiful and of large size, and
in this respect, as well as in several of the above features, the Eastern
Grounds resemble the Brown Ridges. The bottom is composed of
smooth sand, or muddy sand, with some gravelly and stony areas
in parts.

The term Eastern Grounds is restricted in the Humber ports to the
ground along the German and Danish coasts, but the shallow grounds
along the north coast of Holland have a similar character, and are
worked a great deal in summer by vessels from Grimsby and Hull, and
by the Yarmouth fleet. These grounds being for the most part smooth
and sandy, comparatively little ‘‘scruff” or unmarketable material 1s found
upon them. Whelks and whelk-spawn are abundant, and also what the
fishermen call teats—z.e., Alcyonium digitatum, Edible crabs are taken
in some numbers, and star-fishes of various kinds are numerous.

The grounds lying off the mouth of the Humber and Wash to a
distance of about 60 miles are the home grounds of the Humber ports,
and the Yarmouth and Lowestoft vessels fish to a considerable extent
about the banks and shoals off the Norfolk coast. Plaice of various
sizes are taken on these grounds, and also haddock, though not so plen-
tifully as on more northern grounds. Soles, brill, and turbot occur, and
also lemon dabs in moderate numbers. Cod and codling and gurnard
are taken, but latchets are only occasionally seen. ‘These grounds pro-
duce an extraordinary quantity of ‘ scruff,” of which the most abundant
constituent is a form known to the fishermen as “curly cabbage,” a fixed
compound gelatinous organism (A“yonidium gelatinosum). Wydroids
(chiefly Sertularia and Hydrallmannia) are also abundant.

The grounds to the east and south-east of.the Dogger are also fished,
and produce chiefly haddock and plaice.

APPENDIX II 367

On the Great Fisher Bank few turbot or brill are taken, and soles are
scarce. ‘The fish belonging to the north and to deeper water are here
most abundant, namely witches (Pleuronectes cynoglossus), haddock, cod,
ling, halibut, and cat-fish. Large plaice are also taken in moderate
numbers, but lemon dabs are scarce or absent. Megrims appear to
occur in small numbers.

Along the English coast north of the Humber cod are extremely
abundant in the spawning season, February and March, one steam-
trawler often landing seventy or eighty score from a week’s fishing.
Plaice, lemon dabs, cat-fishes, ling, coal-fish, and haddock are also
taken. Soles, turbot, and brill occur in the shallower water, long rough
dabs and witches in the deeper. ‘The grounds along the east coast ot
Scotland have a similar character.

In the last few years, since 1891, some steam-trawlers from Grimsby
and Hull have trawled in the summer months off the south coast of
Iceland, at depths from 6 or 7 fathoms up to 4o fathoms. Plaice and
haddock are obtained in abundance, and of very large size, much larger
than those caught in the North Sea; the majority of the plaice are from
27 to 33 inches in length, the haddock from 19 to 33 inches. Common
dabs, whiting, witches, megrims, halibut, cod, ling, cat-fish, and skate
are all plentiful. The so-called ‘“ Norway haddock,” mentioned in
Appendix I, as viviparous, is also taken in numbers, and landed for sale
at Grimsby, where however it does not fetch a very high price.

In consequence of the great demand for fish, and the profit to be
made by supplying this demand, the number of steam-trawlers belong-
ing to Hull and Grimsby has become very large. It has been difficult
for all these vessels to obtain constantly sufficient supplies of fish in the
North Sea, and consequently they have gone long distances in various
directions in search of unexhausted grounds. While some were dis-
covering new trawling grounds on the coast of Iceland, others were
shooting their trawls on the shores of ‘the Bay of Biscay, landing their
catches at Plymouth. In 1892 a number fished in Vigo Bay, on the
north-west coast of the Spanish Peninsula. On these southern coasts
hake often form the most important constituent of the catch.

Other Humber steam trawlers have fished for some months in the
year in the Irish Sea and off the west coast of Scotland, landing their
catches principally at Fleetwood. ‘The extent of trawling ground along
the west coast of Ireland is not very great, and I have not heard of any
English trawlers making trial of it ; but local boats of small size trawl
in Galway Bay.

Long-line fishing is carried on over most of the trawling grounds
mentioned in the neighbourhood of the British and Irish coasts. On
the east coast the two principal ports for long-lining are Harwich and

368 MARKETABLE BRITISH MARINE FISHES

Grimsby. At both of these ports welled smacks are used, and the cod
caught are brought back alive in the well, and kept alive for a time in cod
chests in the harbours. Whelks are largely used for bait, and the fishing
grounds are about the Dogger Bank and off the north-east coast of
England. Haddocks are also caught, as well as ling, skate, cat-fishes,
and coal-fish. Cromer Knoll, a bank at the south end of the Outer
Dowsing, is a favourite ground for long-lining in winter. Winter is the
principal time for long-lining in the North Sea; after the beginning of
April the smacks used to go to Iceland and Faroe and fish with hand
lines, salting the fish on board. In summer and autumn the boats use
hand lines in the North Sea. At present the Faroe, Shetland, and Iceland
grounds are worked chiefly by large steamers fitted with wells, belonging
to Grimsby, and these vessels bring back enormous numbers of halibut,
as well as ling, cod, coal-fishes, cat-fishes, and skate. It1is a striking sight
to see the long rows of immense halibut and other fish laid out on the
Grimsby pontoon when one of these vessels lands her catch from the
deep northern grounds. In the North Sea in winter the bait chiefly used
is whelks, but for the more northern grounds the vessels purchase small
coal-fish and herrings at Lerwick to bait the lines.

North of the Farn Islands long-lining is carried on from a large
number of small fishing ports on the English and Scotch coasts by
means of smaller sailing boats without wells. Haddock are the fish
principally caught by these boats, and mussels are chiefly used for bait.

In the south-west long-lining is carried on principally at Plymouth.
The boats used are small and open, mostly about twelve tons burthen.
The fish caught in largest numbers is conger, and this being a nocturnal
fish the lines are always shot at night. Cod, ling, and pollack are also
taken, as well as ray and skate. The grounds fished extend from Start
Point to Land’s End, and to a distance of 30 or 40 miles from the
coast.

} JS

¢ rf . Be
NY . \ Ga 4
- PO NT eat Temenos ¢ 7 \P >

Eastern

Se : 54
~~ Trtigoland 3

Terschelling ym = r
Dolarti-

R cS

if
/
Walcheren@) 4
West Sche/de [

fs

10 Longitude West 8 of Greenwich
—
The Edinburgh Geographical Institute

t

+ 6 Longitude East 8 of Greenwich 10 |

Contours are drawn at 600,1500 and 3000 feet above Sea Level

—<——— ——d
John Bartholomew & Co

268 MARKETABLE BRITISH MARINI

5 Lon §. 10°R.of Greenwich 15 20

= = = a}
: John Bartho! y & C
s & drawn at 600 and 1000 feet above Sea Level oe SARE ,

res

iS J) WEST. coasT
EUROPE
=n Scale of English Miles

5 Oo 5 Long 10°E.of Greenwich ay 20

The Edinburgh Geographical Institute

n C
Condfurs are drawn at 600 and 1000 feet above Sea Level John Bartholomew & Co

INDEX

INDEX

A

Act, Sea Fisheries (Scotland) Amendment,
19; Salmon and Freshwater Fisheries,
20 ; Sea Fisheries Regulation, 20

Adhesive eggs, $7

Agassiz, Prof. Alexander, 7

Alcyonidium gelatinosum, 366

Alcyonium digitatum, 366

Allman, Prof., 4

Ampelisca, 121

Amphioxus, 37

Amphiura filiformis, 125

Anableps, 361

Anarrhichas lupus, 345

Anchovy, characters of, 149, 182 ; habitat,
182 ; breeding of, 183 ; egg of, 183 ; larva
of, 184 ; migrations of, 185

Angel fish, 43

Angler, characters of, 337 ; habits of, 33
spawn of, 339 ; larvee of, 340

Angler family, 54, 337

Anguilla vulgaris, 196

Aphrodite, 123

Argentine, 47

Arnoglossus laterna, 274

Artificial propagation, 140

Atherines, 56

B

BACK-BONED animals, 32, 33

Ballantrae Bank, 13

Ballan wrasse, 57

Bass, 38, 51

Bateson, Mr. William, 28

Belone vulgarts, 93

Berrington, Mr., 20

Bib, 49, 280

Blennies, 56, 343; viviparous, 356, 358,

359
Boar-fish, 53, 320
Bonito, 312

Bottom fishes, 58

Bourne, Mr. G. C., 22

Brill, characters of, 210, 267; eggs and
larvae of, 268 ; growth of, 270

Brittle-stars, 123

Brook, Mr. George, 16

Brosmius brosme, 302

Buckland, Mr. Frank, ro, 11

Bullheads, 326 ; eggs and larve of, 327

Burbot, 87

Butter-fish, 91, 344

c

CALANDRUCCIO, on transformation of Zep-
tocephali, 194, 198, 204

Calderwood, Mr. W. L., 20

Capros aper, 320

Cat-fish, 56, 344 ; characters of, 345 ; eggs
and larva of, 345, 346 A

Ceratium tripos, 130

Chzetopods, 123

Clupea harengus, 150; sprattus, 1643; pil-
chardus, 168; alosa, finta, 178 3 sapi-
dissema, 179

Coal-fish, characters of, 280, 293 ; eggs and
larvee of, 293 ; habits of young, 294

Cod, characters of, 280, 283 ; egg of, 283 ;
larva of, 284; growth and development
of, 284

Cod family, 49, 279; species of, 280;
habits of, 281 ; eggs and larve of, 282

Commission, Royal, on Trawling for
Herrings, 4 ; on Beam Trawling, 8, 14 ;
United States, of Fish and Fisheries, 9 ;
for investigation of German Seas, 9

Conger, 48 ; characters of, 199 ; habitat and
food, 199; breeding of, 83, 200; male,
200, 201; death of mature females in
aquarium, 202 ; larva of, 204

Copepods, 126

Cottus, 324, 326

Cotlus scorpius and bubalis, 326

Cromer Knoll, 368
Crustacea, 53

Cuckoo, 320

Cyclopterus lumpus, 91, 349
Cyprinodontide, 357

D

DAB, common, characters of, 209, 223;
eggs and development of, 224; growth
of, 226

Dannevig, Captain, 27; Mr. Harald, 30

Day, Dr. Francis, 11

Definition of fishes, 3

Development of egg, 99

Dog-fishes, 37 ; spotted ditto, 41 ; eggs of,
64, 85

Dogger Bank, 364, 366

Dorsal fins, 35

Dragonet, 55

Drift-net fisheries, 59, 365

Dunn, Mr. Matthias, 11

E

EAGLE rays, 356

Eastern Grounds, 114,

Echinoderms, 34, 123

Eel, 48; characters of, 196; habitat of,
196 ; breeding of, 83, 196; larva of, 198

Kel family, 48, 192; spawning in, 192;
species of, 196

Egg-membrane, 86

Electric rays, 43

Embiotocide, 357, 361

Engraults encrasicholus, 182

Ewart, Prof., 12, 16

LExocetus, 93

37; 366

F

FATHER-LASHER, 324

Fertilisation, 67 ; artificial, 82

Fins, 35

Fishery Board for Scotland, 12, 16
Fishery Department of Board of Trade,

20

Fishing Grounds, 363

Fishmongers Company, 23

Flapper-skate, 43

Flat-fish family, 50, 208 ; species of, 209 ;
eggs and larvee of, 211; transformation
of, 104, 211

Floating eggs, 94

Flounder, characters of, 209, 227; time
and place of spawning, 229 ; disease of,
231; reversed specimens, 231 ; eggs and
development of, 232 ; transformation of,
104, 232

INDEX

Flying fishes, 49

Food of fishes, 118

French sole, 257

Frog-fish, 337

Fryer, Mr., 20

Fulton, Dr. Wemyss, 22, 24

G

Gadus morrhua, 283; eglefinus, 287;
merlangus, 290 ; virens, 293 ; pollachius,
294

Gambusia patruelis, 360

Garfish, 206 ; eggs of, 93, 206

Garfish family, 48, 206

Garland, steam fishing yacht, 19

Gar-pike, 48

Garstang, Mr. W., 22

Gasterosteus, QI

Generative organs, 62; of dog-fishes, 63,
64; of bony fishes, 65, 66

Germ, 67, 86

Germon, 312

Gill-rakers, 131

Gills, 33, 35

Gobies, 55 ; nest of, 91 ; larva of, 102

Granton Marine Station, 17

Grassi, on transformation of Leptocephalz,
194, 198, 204

Great Fisher Bank, 364, 367

Green, Rey. W. Spotswoode, 25

Grey mullet, 57, 334; thick-lipped, 335

Guard-fish, see Garfish

Gunnel, 91, 344

Gurnards, characters of, 325, 328; eggs
and larvee of ; 33

Gurnard family, 54, 324; species of, 324

H

TIADDOCK, characters of, 280, 287; food of,
287 ; eggs and larve of, 288 ; young of,
28

Haddon, Prof., 25, 26

Hag-fish, 18, 37

Hake, characters of, 280, 298; eggs and
larva of, 299

Halibut, characters of, 242 ; spawning of,
243

Hatchery, at Dunbar, 27; at Arendal, 140 ;
in Newfoundland, 140

Heape, Mr. Walter, 21

Heincke, Dr., 19

Hermit-crab, 120

Herring, characters of, 148, 150; habitat,
150 ; Spawning periods and places, 151 ;
races of, 155; egg of, 88, 157; larva of,
159; transformation of, 159; growth of,

159

INDEX

Herring family, characters of, 147 ; species
of, 148 ; eggs and larvee, 149

LTippoglossoides limandotdes, 244

fippostlossus vulgaris, 242

Holt, Mr. Ernest W. L., 26, 28

Horse-mackerel, 318

Huxley, Prof., 16

fydrallmannia, 366

I

IMMATURE fish, 108 ; sizes of, 109
Irish Fisheries Survey, 25

JELLY-FISH, 33, 34
John dory, characters of, 321 ; breeding of,

32

3
John dory family, 53, 320

L

Labrax lupus, 89

Lancelet, 37

Larvee, 102

Latchet, 115, 117, 325, 365

Lemon dab, characters of, 236 ; habitat of,
237 ; spawning of, 237; larva of, 239;
growth of, 239

Lemon sole (or lemon dab), 236 ; (or sand
sole), 257

Lepadogaster, 90

Lepidorhombus megastoma, 271

Leptocephali, 193; transformation of, into
conger, 194 ; JMorrzszz, 204

Limits of size proposed for saleable fish,
138

Ling, characters of, 280, 295; eggs and
larvee of, 296

Liparis, 90 ; vulgaris and Montagu, 351

Long-line fishing, 367

Long-nosed skate, 43

Long rough dab, characters of, 244 ; food
of, 245; spawning of, 245; young of,
247

Lophius piscatorius, 337

Lota vulgaris, 87

Lower animals, tribes of, 33

Lump-sucker, 55 ; characters of, 349 ; eggs
of, 89, 91, 350; young of, 350

Lung-fishes, 37

M

MACKEREL, characters of, 312; eggs and
larvee of, 314 ; migrations of, 313

Mackerel family, 53, 311 ; species of, 312

Mactra subtruncata, 122

Male sole, 21

Malm, Prof., on transformation of flat-
fishes, 7, 211

Marine Biological Association, 16

Marked plaice, movements of, 29

Matthews, Mr. Duncan, 19, 20

Maturity of fishes, 108

McIntosh, Prof., 8, 14

Megrim, characters of, 210, 271 ; eggs and
young of, 272

Merluccius, 96 ; vulgaris, 298

Merry sole, 237

Micropyle, 67

Migrations of fishes, 112

Miller’s thumb, 324

Milt, 71 ; size of, compared with roe, 73

Molluscs, 34 ; as food of fishes, 121

Molva, 96 ; vulgarzs, 295

Monk-fish, 43, 545 337

Morris, 194, 204

Motella, 96; tricirrata, cimbria, mustela,

300
Mugil chelo, 335
Mullus surmulletus and barbatus, 306
Murray, Dr. John, 17
Mustelus vulgaris and levis, 355
Myliobatidze, 356
Myxine glutinosa, 18

N

Nerets, 123

Nest of sticklebacks, 91
Noctiluca, 98

Norway haddock, 356
Nyctiphanes, 129

O

Ophiura albida, 123
Osmerus eperlanus, 93, 188
Ovary of dog-fish, 62, 66

P

PARENTAL care in fishes, 90

Pectoral fins, 35

Pelamid, 312

Pelvic fins, 35

Perch family, 51 ; eggs of, 89 .

Pilchard, characters of, 168; habitat of,
170; breeding of, 170; egg of, 172;
larva of, 173; transformation of, 173;
growth of, 177

Pipe-fishes, 58

Piper, 325, 329, 330

374

Plaice, characters of, 209, 213; time and
place of spawning, 215 ; eggs and larva,
216; transformation of, 218 ; growth of,
219 ; small, on eastern grounds, 221

Pleuronectes platessa, 213; limanda, 223 ;
flesus, 2273 cynoglossus, mIucro-
cephalus, 236

Pollack, 280, 294

Porbeagle, 41

Pout, 280

Prince, Mr., 19, 23

Pristiurus melanostoma, 65

Prohibition of trawling in certain areas, 19

Protection of young fish, 135

Pteroplatea micrura, 356, 357

922°

#“I9 >?

R

RAFFAELE, on eggs probably belonging to
eel family, 195

Rate of growth, 110; of spawning, 79

Rays, 37

Ked mullet, characters of, 306; eggs and
laryze, 307

Red mullet family, 52, 306

Rhombotdichthys, transformation of, 212

Rhombus, 96 ; vaximus, 260 ; levis, 267

Rocklings, characters of, 281, 300; eggs
and larvee of, 300; habits of young, 301

i

Roes, 65 ; relative sizes of hard roe and soft
roe, 73
S

SALMON Family, 46, 187 ; eggs of, 87

Sand-eels, 303 ; breeding of, 304

Sand-sole, characters of, 210, 257

Sand-star, 123

Sardine, French name for pilchard, 169 ;
size of, used for tinning, 169 ; in Mediter-
ranean, 170

Sars, Prof., on buoyant spawn, 5 ; on de-
velopment of cod, 284; on young had-
dock, 288

Saury-pike, 48

Scad, characters of, 318 ; breeding of, 319

Scad family, 52, 318

Scald-hack, 210, 274

Scald-fish, characters of, 210, 2743; eggs
and young of, 275

Scaly fishes, characters of, 38

Scomber scomber, 312

Scombresox, 93

Scorpenide, 357, 362

Scrobicularia, 122

Scyllium caniceula and catiulus, eggs of, 64

Sea-breams, 51, 309 ; breeding and spawn
of, 310

Sea-cat, 344

Sea Fisheries Districts, 20

Sea-horse, 58

Sea-scorpion, 324, 326

INDEX

Sea-trout, 47

Sebastes norvegicus, 356

Serlularia, 366

Sexes, proportions of, in fishes, 74

Shad, 46; characters of, 178; American,
46, 179; allis, 178 ; twait, 178 ; habitat,
178 ; breeding, 179 ; eggs of, 179; larva
and growth, 180, 181

Shanny, 89, 343

Shark, Greenland, 41 ; blue, 41 ; basking,
41

Shrimping, in relation to destruction of
small fish, 113, 136

Silver Pit, 364

Skates, 42

Skipper, 48

Smelt, 47; characters of, 188; habitat,
food and breeding, 188 ; larva of, 189 ;
growth of, 190

Smooth-hound, 41

Sole, characters of, 210, 249 ; food of, 249;
breeding of, 251 ; larvae and transforma-
tion of, 251 ; history of young, 255 ; spawn-
ing of, 80

Solea, vulgaris, 249; lascaris, 257 ; lutea,
258 ; varzegata, 259

Solen, 122

Solenette, characters of, 210, 258

Spawn of herring, 4; buoyant, 5

Spawning, 70; season, 83 ; cessation of, in
confinement, 83

Species, meaning of, 40

Sperms, 83

Spinachia, 91

Spineless fishes, 49

Sprat, characters of, 148, 164; habitat of,
164; breeding of, 164; eggs of, 166;
transformation and growth, 167 ; migra-
tions, 168

Spur-dogfish, 41

Squid, 123

St. Andrews Marine Laboratory, 17

Star-fishes, 33, 34

Statistics of fish captured, 143

Steenstrup, on transformation of flat-fishes
212

Sticklebacks, 56

Sting-rays, 43, 356

Sturgeon, 39

Suckers, diminutive, 351; spawn of, go,
351 ; larva of, 352

Sucker, double-spotted, egg of, 90

Sucker family, 55, 349

Surface fishes, 58

Swimming crab, 120

a
TESTIS, 71
Thickback, characters of, 210, 259; larva
of, 260

INDEX 375

Thornback, 44

Thresher-shark, 41

Tope, 41

Top-knots, characters of, 276; eggs and
larvee, 277

Torpedo, 65

Torsk, 49, 281, 302

Tow-net, 5, 97

Transformations of fishes, 99 ; of cod, 104 ;
of flounder, 103

Trawl fishery, 59, 365

Treatise on Common Sole, 23

Trigla hirundo, 117, 328; gurnardus,
cuculus, Lyra, 328

Trout, 47

Trygonidz, 356

Tub-fish, 325, 329, 330

Tunny, 312

Turbot, characters of, 210, 260; food of,
118, 132, 261; eggs and larve, 261 ;
growth of, 266

Tusk, characters of, 281, 302; eggs and
larvee of, 303

V

VENTRAL fins, 35
Viviparous fishes, 65, 355

W

WALPOLE, Mr. Spencer, 10

Whale, characteristics of, 33

Whitebait, 161, 167

Whiting, characters of, 280, 290; eggs
and Jarva of, 291; habit and growth of
young, 292

Whiting-pout, 49, 280

Witch, characters of, 233; spawning of,
234; larva and growth, 235

Wolf-fish, 344

Worms, 34; as food of fishes, 123

Wrasses, 57

W

YOLK, structure of, 94, 95

Z

Zeugopterus, 96; punctatus wunenaculatus
norvegicus, 276

Zeus faber, 321

Zoarces viviparus, 356

RICHARD CLAY AND SONS, LIMITED, LONDON AND BUNGAY.

eaetk
}
ie | }
nippy ft
Of pints ta
a4
\
Mi Ls

o

4
a er

[eye

i

, te

a? an i)

- =>

p
a

Be!

ie
i a)
oft
\
e i
{
i
4
t.5
=
a is

ve

Wass
pe etaw a
ia (Pale se
7 ot
re '

4 qt } ( i
yy e
HR i eh
} iit, &

Ne

sayeeed) ae
AVS eee
Hl lele
ite

1 Pea Vn

Me, ar ba
1 ny
Mild een,

"Om se!
ha ee ee

Din