Notes on fishes of the genus Brachygobius

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NATURAL HISTORY,
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14 FIELDIANA • ZOOLOGY

P- '^ Published by

CHICAGO NATURAL HISTORY MUSEUM

Volume 39 April 25, 1968 No. 14

NOTES ON FISHES OF THE GENUS
BRACHYGOBIUS

Robert F. Inger
^ Curator, Division op Rbptilbb and Amphibians

The gobies of the genus Brachygobius Bleeker inhabit both brack-
ish and fresh waters of the Oriental region. All the species are small
(rarely over 30 mm.) and banded with black and yellow. Material
recently acquired by Chicago Natural History Museum from North
Borneo contained fishes apparently belonging to a new form. This
discovery led to a study of previously described species with the result
that B. aggregatus Herre was found to be a composite species in-
cluding a new one from Borneo. These two forms are described in
this paper.

The generic diagnosis of Brachygobius given by Koumans (1953)
contains several statements requiring modification. According to
Koumans, predorsal and opercular scales are always present and the
anal and second dorsal fins have from seven to ten branched rays.
Actually, not all species have opercular scales. In some species pre-
dorsal scales may be present or absent, depending on size; in others
the predorsals seem to occur on all individuals; in still others they
are always absent. The anal and second dorsal usually have seven
or eight branched rays, but in two species six is the common number.

In general, Brachygobius has a short heavy body, cylindrical ante-
riorly, compressed posteriorly. The head is flattened between the
eyes, which are always larger than both the snout and the inter-
orbital. The mouth is oblique, with a rather prominent lower jaw.
The conical teeth are in two or three rows in each jaw. The sensory
papillae of the head are arranged in longitudinal rows. The yellow
and black coloration is characteristic of the entire genus.

I am grateful to Dr. Leonard P. Schultz of the United States
National Museum for the loan of material. The figures are the

Library of Congress Catalog Card Number: 58-9929
No. 839 107

NATURAC

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108 FIELDIANA: ZOOLOGY, VOLUME 39

work of Mr. E. John Pfiffner, Staff Artist, Chicago Natural History
Museum.

The following abbreviations are used : CNHM, Chicago Natural
History Museum; USNM, United States National Museum.

The following specimens were examined: 8 paratypes of B. xan-
thomelas Herre (USNM 101226), 10 topotypes of sua Smith (USNM
119566), 9 topotypes of aggregatus Herre (CNHM 40444-52), 56
specimens of doriae Giinther (CNHM 51677), and 34 Bornean fishes
belonging to the two new species. No specimens of xanthozona
Bleeker or nunus Hamilton were seen. A summary of counts is
given in Table 1.

KEY TO THE GENUS BRACHYGOBIUS BLEEKER

lA. Mid-lateral scales about 50; four black bands; anal fin entirely black
(Giinther, 1861) xanthozona Bleeker

IB. Mid-lateral scales under 30; other characters various 2

2A. Two black bands reaching mid-ventral line posterior to base of anal fin ... 3

2B. One black band reaching mid- ventral line behind anal fin 5

3 A. A black head band passing through eye; anal with at least seven branched
rays X. . . . . nunus Hamilton

3B. No black head band or head band touching posterior corner of orbit; anal
with six branched rays 4

4A. No predorsals; anal band reaching mid- ventral line aggregatus Herre

4B. Seven or eight predorsals; anal band not reaching mid-ventral line.

kabiliensis, new sp.

5 A. First black trunk band ending at dorsal origin; no predorsal or opercular
scales; basal portion of first dorsal not black anteriorly . .xanthomelas Herre

5B. First black trunk band overlapping at least anterior half of base of first
dorsal; basal portion of first dorsal black anteriorly 6

6A. First black trunk band dorsally not extending forward of gill opening;
black pigment of second dorsal on last three or four rays only; no pre-
dorsals; opercular scales present or absent sua Smith

6B. First black trunk band beginning opposite center of opercle; black pigment
of second dorsal on all rays; opercular scales present; predorsals present
or absent 7

7A. Entire first dorsal, except narrow margin, black; at least basal two-thirds
of ventrals black; black of pectoral covering basal two-thirds of fin.

doriae Giinther

7B. Last one or two rays of first dorsal colorless; at most basal halves of first
three ventral rays black, usually black limited to interspinous membrane;
black of pectoral covering less than half of fin sabanus, new sp.

Brachygobius nunus Hamilton

Gobius nunus Hamilton, 1822, Fishes of Ganges, p. 54 — Ganges below Cal-
cutta, India; Day, 1878, Fishes of India, p. 297; Hora, 1929, Mem. Indian
Mus., 9, pi. 14, fig. 5.

INGER: FISHES OF THE GENUS BRACHYGOBIUS 109

Brachygobius nunus (part) Koumans, 1941, Mem. Indian Mus., 13: 269; 1953,
Fishes Indo-Austr. Arch., 10: 194.

Ctenogobius nunus Hora, 1934, Rec. Indian Mus., 36: 488.

Gobius alcockii Annandale, 1906, Jour. Asiat. Soc. Bengal (N.S.), 2: 201,
fig. 1 — Port Canning and Calcutta, India.

Ctenogobius alcockii Hora, 1923, Mem. Indian Mus., 5: 744.

Hora's publication (1929) of Hamilton's manuscript drawing of
nunus and his subsequent notes (Hora, 1934) on the relationship of
alcocki to nunu^ have clarified the identity of Hamilton's fish. Kou-
mans' work (1941, 1953) has only clouded the picture by placing
three distinct species in the synonymy of nunus.

From an examination of more than 100 of these little gobies, I
conclude that, although intraspecific variation in color pattern does
occur, it never has sufficient range to include the patterns of nunus,
doriae Giinther, sua Smith, and xanthomelas Herre. Grouping the
specimens examined according to the color patterns associated with
these names results in series that also differ in counts (see Table 1).

Hamilton's manuscript figure of nunus clearly shows four black
bands on the body: a broad one in the pectoral region, a narrow one
from the origin of the second dorsal to the fore part of the anal base,
a second narrow one from just behind the second dorsal to behind
the anal, and a third narrow one on the caudal base. Hamilton's
description (1822) mentions a black band passing through the eye
and a second on the opercle; these are also shown on the figure.

Brachygobius doriae Giinther never has more than three black
bands behind the head. The bands are usually wider than the light
interspaces, whereas the reverse is true in nunus. Some individuals
of doriae have a small black spot in front of the middle body stripe;
otherwise there is little variation. Koumans (1941, 1953) has given
the color pattern of doriae first in his descriptions of nunu^, that of
true nunu^ appearing only as a "variety." His figure (1953) agrees
perfectly with the original description of doriae (Giinther, 1868).

The known distribution of nunus includes India and Burma.

Brachygobius doriae Giinther

Gobim doriae Gunther, 1868, Ann. Mag. Nat. Hist., (4), 1: 265, pi. 12, fig. A—
Sarawak.

Brachygobius doriae Bleeker, 1874, Arch. N6erl. Sci. Ex. Nat., 9: 315; Harden-
berg, 1936, Treubia, 15: 252; Inger, 1955, Fieldiana, Zool., 37: 77.

Brachygobius nunus (part) Koumans, 1941, Mem. Indian Mus., 13: 269; 1953,
Fishes Indo-Austr. Arch., 10: 194, fig. 48.

110 FIELDIANA: ZOOLOGY, VOLUME 39

Brachygobius sua Smith

Thaigobiella sua H. M. Smith, 1931, Proc. U. S. Nat. Mus., 79: 35, fig. 17—
Bangkok, Thailand.

Brachygobius sua H. M. Smith, 1945, Bull. U. S. Nat. Mus., no. 118, p. 549.

Brachygobius nunus (part) Koumans, 1953, Fishes Indo-Austr. Arch., 10: 194.

This goby, grouped by Koumans with doriae and nunus, differs
from the latter in having only three complete black bands on the
body. One of the ten topotypes examined had a black spot dorsally
on the caudal peduncle. The presence of three black bands recalls
doriae, but the bands of sua are much narrower than those of doriae.
Furthermore, black pigment is restricted to a small triangle at the
posterior basal portions of the anal and second dorsal in sua, whereas
in doriae the pigment almost completely covers these fins. Differ-
ences between sua and doriae in counts are shown in Table 1.

This form has been reported only from Thailand.

Brachygobius xanthomelas Herre ^

Brachygobius xanthomelas Herre, 1937, Bull. RaflSes Mus., no. 13, p. 43, pi. 4

— Mawai District, Johore.
Brachygobius nunus (part) Koumans, 1941, Mem. Indian Mus., 13: 269; 1953,

Fishes Indo-Austr. Arch., 10: 194.

In addition to the points noted in the key, the color pattern of
xanthomelas differs from that of sua in the amount of black on the
second dorsal and pelvics. In xanthomelas the dark pigment forms
a triangle extending transversely across that fin. The pelvics of
xanthomelas have a small black spot, those of sua have none. The
two also differ in the length of snout, that of sua being distinctly
shorter. Differences between this goby and doriae and nunus are
indicated by the key and Table 1.

As yet this fish is known only from the Malay Peninsula and
Singapore.

Brachygobius kabiliensis, new species. Figure 19.

Holotype. — Chicago Natural History Museum no. 47991 from
Kabili River, Sandakan District, East Coast Residency, North
Borneo. Collected in mangrove swamp February 5-6, 1937, by
A. W. Herre.

Paratypes.—CNBM 59623 (5) from the type locality; CNHM
44989 (2) from Mile 2, Sandakan, Sandakan District.

Description (data for holotype in parentheses). — Dorsal vi — i,6
(vi — i,6); pectoral 12-14 (14) (mean 13.4); ventral i,5 (i,5); anal

INGER: FISHES OF THE GENUS BRACHYGOBIUS

111

i,6-7 (i,6) (one fish with i,7) ; mid-lateral scales 22-23 (22) (mean
22.6) ; 7-8 predorsals (7) ; 7 scales in transverse series between origins
of anal and second dorsal; standard length 11.5-15.5 mm. (14.0);
head 2.76-2.87 (2.76).

Body robust, cylindrical anteriorly, compressed posteriorly; dor-
sal profile convex, rising gradually to origin of first dorsal; ventral
profile convex, less arched than dorsal.

Fig. 19. Holotype (CNHM 47991) of Brachygobius kabiliensis, new species.
Standard length 14.0 mm.

Head cylindrical, flattened between eyes; snout blunt; nostrils
separated, anterior with short tube overhanging rostral groove, pos-
terior at upper anterior corner of orbit and without tube; mouth
oblique, lower jaw protruding a little; maxilla extending to below
anterior border of eye; teeth conical, in two rows in both jaws; tongue
truncate; eye 3.5 times in head, diameter longer than snout, shorter
than opercular width; interorbital two-thirds of eye.

Sensory papillae in longitudinal rows, a suborbital row of rela-
tively large, widely spaced papillae; three rows on cheek; upper
cheek row angulated, running from below posterior margin of pupil
to end of preopercle, and consisting of small papillae; middle cheek
row of four large, widely spaced papillae, beginning below anterior
margin of orbit and ending below posterior margin of orbit; lower
cheek row of small papillae running forward from below end of orbit
to preorbital, where it sends a short, oblique limb forward above
maxilla; one large papilla between middle and upper cheek rows at
end of former; a long row from chin following lower jaw and lower
edge of cheek, curving up along posterior border of preopercle; a
vertical row on opercle anteriorly, intersected in lower third by a
short, longitudinal row; a short, oblique row on upper, posterior
half of opercle.

112 FIELDIANA: ZOOLOGY, VOLUME 39

Pectorals inserted in lower half of side; base vertical; fin rounded,
extending a little beyond ventrals to vent; ventrals united, inter-
spinous membrane well developed; fin narrowly missing anus; origin
of first dorsal opposite center of ventrals or about two scales behind
pectoral base; tip of depressed fin separated from second dorsal by
half scale; origin of second dorsal opposite that of anal; margin
rounded; bases of second dorsal and anal subequal, slightly longer
than that of first dorsal; origin of anal immediately behind genital
papilla; rays of second dorsal longer than those of anal or first dorsal;
caudal damaged at tip, probably truncate or rounded.

Scales ctenoid; seven predorsals, first largest and beginning im-
mediately behind orbits; opercles completely covered by large scales;
head otherwise naked; fins without scales.

Color in life bright yellow with four black ban^&^Herre, 1940) ;
in alcohol yellow fades to pale brown; snout dusky above; cheeks
with scattered round spots; large first predorsal black; scales of
opercle and nape with dark margins.

First black band beginning two scales before origin and extend-
ing back to base of second or third ray of first dorsal; ventral limit
of band at mid-lateral line or at level of lower edge of pectoral ; maxi-
mum width of band three scales, slightly less than eye diameter; band
extends on to first dorsal occupying basal third or half of first three
or four rays and included membrane.

Second band beginning at base of fifth or sixth ray of first dorsal
and reaching back to fifth ray of second dorsal; separated ventrally
from anal base by one or one and one-half scale rows; dorsally split
by light saddle covering scale at base of first ray and scale before
origin of second dorsal and paravertebral scale; maximum width of
band equal to postorbital part of head ; dorsally separated from first
band by one or two scales; extending on to second dorsal, covering
basal quarter or third of second to fifth rays.

Third band roughly vertical, separated by one to one and one-half
scales from end of anal and second dorsal; posterior margin concave;
band reaching mid-ventral line, three scales wide, subequal to eye
diameter.

Fourth band at end of caudal peduncle; posterior margin convex,
at origin of fin, except for distinct projection on one scale over the
bases of those rays just above the center; width of band in center
three scales.

INGER: FISHES OF THE GENUS BRACHYGOBIUS 113

Pectoral fin with narrow vertical black bar in basal fifth, bar nar-
rower than pupil diameter; sometimes limited to a round spot; anal
and ventral fins unmarked.

Remarks. — When Brachygohius aggregatus (type locality Duma-
guete, Negros, Philippine Islands) was described, 67 specimens from
the Kabili River, North Borneo, were listed as paratypes (Herre,
1940). The holotype and five paratypes of kahiliensis are part of
that series.

According to Herre's description, aggregatus has no predorsals
and from none to two opercular scales. Nine topotypes (CNHM
40444-52) agree on these points. This is in marked contrast, how-
ever, to the Kabili River fishes, which, as noted above, have pre-
dorsals from the orbit to the dorsal and completely scaled opercles.

The Negros and North Bornean fishes also differ in coloration.
The first band in aggregatus starts anterior to the gill opening and
covers the upper comer of the opercle; the mid-ventral line below the
band is black. In kahiliensis the band begins behind the gill opening,
never invades the opercle, and lacks a mid-ventral extension. The
second black band reaches the anal base in aggregatus but fails to do
so in kahiliensis.

The key and Table 1 bring out differences between kahiliensis
and other species of Brachygohius.

Brachygohius sahanus, new species. Figure 20.

Holotype. — Chicago Natural History Museum no. 47990 from
Lamag, Kinabatangan District, East Coast Residency, North Bor-
neo. Collected June 18, 1949, by J. A. Tubb.

Para<i/pes.— CNHM 44987 (19) from the type locality; CNHM
44988 (5) from Abai, Sandakan District; CNHM 44990 (1) from
Mintak, Kinabatangan District.

Description (data for holotype in parentheses). — Dorsal vi — i,7-8
(vi — i,7) (mean of branched rays 7.7); pectoral 15-16 (16) (mean
15.8) ; ventral i,5 (i,5) ; anal i,7-8 (i,7) (mean i,7.7) ; mid-lateral scales
24-27 (24) (mean 25.0); 0-2 predorsals (0); 9 scales in transverse
series between origins of anal and second dorsal; standard length
11.5-26.5 mm. (16.0); head 2.46-2.72 (2.71).

Body moderate to robust, subcylindrical anteriorly, compressed
posteriorly; dorsal profile convex, highest point at origin of first dor-
sal; ventral profile weakly convex or horizontal.

114 FIELDIANA: ZOOLOGY, VOLUME 39

Head cylindrical, flattened between eyes; snout blunt; nostrils
separated, anterior in short tube reaching gape, posterior at front
border of orbit and without tube; mouth oblique, lower jaw promi-
nent; maxilla reaching below anterior border of eye; teeth conical, in
two rows in both jaws, occasionally inner row irregular, giving im-
pression of a third row, teeth of outer rows slightly enlarged; tongue
truncate; eye 3.5-4.0 in head, much longer than snout, only slightly
greater than interorbital, less than opercular width.

Sensory papillae in longitudinal rows; a semicircular suborbital
row of widely spaced, relatively large papillae; three rows across
cheek; upper cheek row angulated, running from below center of
orbit to end of preopercle, and consisting of small papillae; middle
cheek row of rather large, widely spaced papillae, «hort, beginning
just behind suborbital row; lower cheek row runnings forward from
below posterior border of orbit to preorbital where it sends a short
oblique limb forward above the maxilla; a long row beginning on
chin, following curve of lower jaw and interopercle, then curving up-
ward along posterior border of preopercle; a vertical row along ante-
rior border of opercle intersected by a short horizontal row from rear
border of opercle; a short horizontal or somewhat oblique row across
middle of opercle.

Pectorals inserted in lower half of side, base vertical, fin rounded,
extending a little beyond ventrals to level of genital papilla; ventrals
united, interspinous membrane well-developed, fin reaching vent or
base of genital papilla; origin of first dorsal one or two scales behind
pectoral base, depressed fin reaching origin of second dorsal or sepa-
rated from it by one scale; origin of second dorsal one or two scales
in advance of anal origin, margin of fin rounded; bases of anal and
second dorsal subequal, longer than base of first dorsal; origin of anal
immediately behind genital papilla; anterior rays of second dorsal
longer than those of anal or first dorsal; caudal bluntly rounded.

Scales ctenoid; opercles scaled in upper third; head otherwise
naked; fins without scales.

Color in life probably black and lemon yellow; in alcohol pale
brownish or yellowish with three complete blackish brown bands on
body; two dark saddles usually present in the light interspaces.

Snout dusky; a broad dark band below eye beginning opposite
anterior margin of pupil and covering cheek and preopercle, contin-
uous dorsally with narrower band crossing top of head immediately
behind interorbital; dorsally this band separated from first trunk
band by yellow interspace subequal to eye; upper half of opercle
dark.

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116

FIELDIANA: ZOOLOGY, VOLUME 39

TABLE I

A summary of counts made on species of Brachygobius Bleeker

(Numbers in body of table refer to individuals)

Second dorsal Anal Pectoral

total rays total rays total rays

7 8 9 10 7 8 9 10 12 13 lU 15 16 17

xanthomelas 13 3 22

sua 7 16 2 4

doriae 12 11 1 12 5 4

sabantis 5 10 5 10 3 11

aggregatiis 4 4 122

kabiliensis 7 61 134

Mid-lateral scales ^y- Predorsal scales Opercular scales

21 22 23 21f 25 26 27 28 Present Absent Present Absent

xanthomelas . . 2 2 8 8

sua 113 8 4 5

doriae 11451 * *

sabanus 5631 4 9 14

aggregatus .... 1 1 3 5 5

kabiliensis 3 4 8 8

* All specimens over 13 mm. have predorsals; all specimens over 10.5 mm. have
opercular scales.

First black band of trunk beginning opposite center of opercle or
slightly more caudad, ending posteriorly opposite base of fourth or
fifth ray of first dorsal ; band reaches mid-ventral line in one-fifth of
fishes from Lamag and in four-fifths of those from Abai; maximum
width subequal to postorbital part of head.

Second band beginning at center of base of second dorsal and
extending one or two scales behind fin; band reaches base of anal
from third or fifth ray to one or two scales behind fin; width sub-
equal to orbit.

Third band at caudal base; in mid-lateral line about two scales
before caudal flexure.

First dorsal black in basal two-thirds to four-fifths except for last
two colorless rays, the black continuous with first trunk band ; second
dorsal with black quadrilateral or triangular area reaching base of fin
and second black band on posterior rays only, anterior rays colorless
at base, a broad marginal, non-pigmented strip; anal with oblique
black area beginning at base of posterior rays and extending forward
to second ray; pectoral with vertical black band near base, varying

INGER: FISHES OF THE GENUS BRACHYGOBIUS 117

in width from pupil diameter to slightly less than width of eye; ven-
trals with few black spots on interspinous membrane, sometimes
basal third of first three soft rays black.

Remarks. — BrachygobiiLS sabaniis differs from doriae, which it re-
sembles most closely, in the averages of some counts, although there
is considerable overlap (see Table 1). The former appears to have
more dorsal and anal rays and fewer mid-lateral scales. But the dis-
tinction between the two is most striking in coloration. In addition
to the points noted in the key, sabanus differs from doriae in the pos-
session of the dark dorsal saddles. Very rarely a small black spot
occurs dorsally in the light interspaces in doriae.

Differences between sabanus and other members of the genus are
brought out by the key and Table 1.

REFERENCES

GtJNTHER, Albert
1861. Catalogue of the acanthopteryg^an fishes in the collection of the British

Museum. 3, xxiii + 586 pp. London, Taylor and Francis.
1868. Descriptions of two new gobioid fishes from Sarawak. Ann. Mag. Nat.

Hist., (4), 1 : 264-266, pi. 12.

Hamilton, Francis
1822. An account of the fishes found in the River Ganges and its branches,
vii + 405 pp., 39 pis. Edinburgh, Archibald Constable and Company.

Herre, a. W.

1940. Notes on fishes in the zoological museum of Stanford University, VII.
New and rare Philippine gobies from the Herre 1936-1937 Oriental Expedi-
tion, and the collections of the Bureau of Sciences. Phil. Jour. Sci., 72: 357-
369, 6 pis.

Hora, S. L.

1929. An aid to the study of Hamilton Buchanan's "Gangetic Fishes." Mem.

Indian Mus., 9: 169-192, pis. 13-23.
1934. The systematic position of Hamilton's species of gobioid fishes from the

Ganges. Rec. Indian Mus., 36: 483-490.

KOUMANS, F. P.

1941. Gobioid fishes of India. Mem. Indian Mus., 13: 205-329.

1953. The fishes of the Indo-Australian Archipelago. 10, xiii + 423 pp., 95 figs.
Leiden, E. J. Brill.

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