Marine Biological Laboratory

AUG :m1 1956
WOODS HOLE, MASS.

RAISING

BAIT FISHES

CIRCULAR 35

FISH AND WILDLIFE SERVICE

UNITED STATES DEPARTMENT OF THE INTERIOR

RAISING

BAIT FISHES

By John Dobie, O. Lloyd Meeheon

S. F. Snieszko, and George N. Washburn

CIRCULAR 35

Fish and Wildlife Service
John L. Farley^ Director

United States Department of the Interior
Douglas McKay, Secretary

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • 1956

For sale by the Superintendent of Documents, United States Government Printing Office
Washinston 25, D. C. Price 45 cents

FOREWORD

At the second annual meeting of the Tri-State Fisheries Con-
ference (Michigan, Minnesota, and Wisconsin) in 1946, a spe-
cial committee was appointed to assemble information on bait
culture and to assign research to the contributing agencies. In
1948, the results of that cooperative project were published in
Circular 12, Propagation of Minnoios and Other Bait Species.
The present publication is a revision of Circular 12 and adds
the results of 5 years of pond investigations by research men in
the Midwestern States.

The following persons contributed to this revision :
Dr. John Dobie, Minnesota Fisheries Research Unit, revised
the sections on production of fish in natural ponds, handling of
minnows, and control of predators. Measurements, weights
and volumes of minnows, and food habits of some minnows
were added to the section on the life histories of important bait
fishes. Dr. O. Lloyd Meehean, United States Fish and Wildlife
Service, rewrote the sections on pond construction and control
of aquatic vegetation. Dr. S. F. Snieszko, United States Fish
and Wildlife Service, rewrote the section on control of
diseases and parasites and added information on use of the new
antibiotics. George N. Washburn, Ozark Fisheries, wrote the
sections on methods of fathead-minnow, creek-chub, and golden-
shiner propagation used by the large commercial hatcheries of
Missouri. John Moyle, Iljalmar Swenson, and Fred Miller,
Minnesota Bureau of Fisheries, reviewed the manuscript.
Harold Condiff and L. N. Nelson generously provided ponds
and field assistance for the Minnesota natural-pond studies.
Ruth Aanes, Minnesota Fisheries Research Unit, typed and
proofread the manuscript.

CONTENTS

Page

Foreword "

Why bait-Fish propagation? 1

Establishing the hatchery 3

Economic considerations 3

Types of ponds 3

Artificial ponds 4

Natural ponds 21

Choosing the fish 23

Operating the hatchery 24

Fertilizing the pond 24

Stocking the pond with adult fish 26

Artificial feeding 27

Handling bait fish 28

Harvesting fish 29

Estimating production 37

Grading fish 39

Transporting and holding bait fish 40

Weed control in ponds 45

Chemical agents 46

Applying chemical agents 49

Spraying equipment 50

Controlling diseases and parasites 50

When to treat 50

Methods of treatment 51

Control of specific diseases 57

Disinfecting ponds and equipment 61

Controlling predators and pests 62

Some important bait fishes 66

White sucker 68

Fathead minnow 78

Creek chub 85

Golden shiner 94

Goldfish 100

Pearl dace 102

Hornyhead chub 103

River chub 104

Blacknose dace 1 05

Longnose dace 1 06

Finescale dace 1 07

Northern redbelly dace 108

Southern redbelly dace 109

Emerald shiner 110

Common shiner Ill

Spotfin shiner 112

Brassy minnow 113

Bluntnose minnow 113

Stoneroller 115

Western mud minnow 116

Bibliography 118

Table of equivalents 121

Index 122

III

WHY BAIT-FISH PROPAGATION?

With the shortage of minnows
in public waters now a reality and
strict regulations on minnow sein-
ing increasing each year, the bait
dealer is faced with the necessity
of rearing his supply of bait fishes
in ponds or other private waters.
Most dealers will find the change
from free-lance seining to propa-
gation of minnows in ponds dif-
ficult but worth while. This cir-
cular presents information on the
culture of bait fishes and is in-
tended as a guide for those inter-
ested in commercial propagation
of minnows.

The growing number of fisher-
men each year has resulted in a
greater fishing load and an in-
creased demand for suitable bait
minnows. In an effort to satisfy
this demand, commercial minnow
dealers have seined lakes and
streams over wide areas and have
trucked their perishable commod-
ity great distances. Consequently,
dealers, fish culturists, sportsmen,
and biologists fear that the supply
of bait fishes has been greatly de-
pleted in many places, and that
the drain on this natural food of
game fishes may become a serious
problem.

Several factors determine
whether seining minnow^s from
natural waters is a wasteful or
profitable undertaking. Seasonal

fluctuations in the availability of
bait fishes are the rule; minnows
are not found in the same pools or
over the same shoals in our lakes
and streams at all times of the
year. These changes in the supply
of minnows are matched by in-
verse fluctuations in demand : there
are fewer calls for bait during
spring and fall when minnows are
plentiful, but a great demand ex-
ists during the warm summer
months when the minnows are dif-
ficult to catch. Some dealers have
constructed outdoor ponds or in-
door tanks large enough to hold
over thousands of fish from tJie
time of their greatest availability
to that of the greatest demand for
them; but the losses are so great
that this method is not recom-
mended as being either good busi-
ness or good conservation.

The natural distribution of com-
mercially important minnow spe-
cies sometimes does not coincide
with the regions where these fish
are most in demand, and expensive
trips must be made great distances
to collect them. Environmental
factors may also restrict the sup-
ply of minnows in an area where
demand for bait is often great.
Frequently, the cooler, more-sterile
waters in the northern fishing re-
gions do not support the needed
quantities or species of bait fishes.

1

WHY BAIT-FISH PROPAGATION?

The rearing of bait fishes is by
no means easy, but the advantages
are many. The cost of raising fish
may be less than the cost of seining
them in distant waters. Also, the
dealer who raises his own fish can
have a nearly uniform supply on
hand at all times to meet the de-
mands, and is freed from the com-
petition with other dealers for min-
nows in public waters.

Minnows raised in ponds are usu-
ally better fed than fish from pub-
lic waters and are more hardy.
Pond-reared fish also benefit from
being seined in smaller numbers and
from being in transit a shorter time.
So, the fisherman who buys these
fish will get better minnows for his
money and will be able to keep them
alive longer.

Everyone benefits from minnow
propagation : the bait dealer is re-
warded by a better and more-con-

sistent business, the sportsman is
supplied a better bait fish, and the
State is aided in conserving its sup-
ply of forage fishes.

Even though minnow propaga-
tion is desirable, dealers who plan
to engage in it should first consider
the problems involved. Fish prop-
agation is more than a simple propo-
sition of combining fish and water
to produce a profit. Considerable
skill and judgment are needed to
select or construct good ponds.
Most dealers need years of practice
before they become proficient at
pond stocking, pond fertilizing, and
pond harvesting. Each pond is a
distinct problem, and conditions in
it may change from year to year.
The beginner in minnow propaga-
tion will do well to start on a small
scale and learn as he builds up his
business.

ESTABLISHING THE HATCHERY

ECONOMIC
CONSIDERATIONS

The bait dealer should consider
local economic conditions before he
establishes a minnow hatchery.
The most important factor is the
retail price of the minnows. This
price must be high enough to pay
production costs plus a fair profit.
If artificial ponds have to be con-
structed, the price received for the
minnows must be high enough to
pay off the principal and interest
on the investment. Topography
and land values must be such as to
allow the selection or construction
of a sufficient number of ponds for
a practical business. One small
pond is not enough for a sound,
full-time business.

The successful dealer considers
the following points to avoid pro-
ducing fish that he cannot sell :

1. Which bait fishes are in greatest
demand in the local market?

2. What size minnows do the fisher-
men want? It is important to know
whether the minnows to be raised arti-
ficially will reach that size in one or two
seasons.

3. In which months do the fishermen
need minnows in the greatest number?
The dealer must determine whether the
pond minnows will be of commercial size
in those months. Some species may be
too large and others may be too small
at the height of the fishing season.

4. Is there a natural supply of the
popular species? In Minnesota, for ex-
ample, fathead minnows are in great
demand for crappie fishing, but these fish
are so abundant in the natural waters
of the State that artificial propagation
is not profitable.

5. Do any habits of a popular species
of bait fish make its propagation unprofit-
able?

6. How hardy are the popular species?
Those fish needed during hot weather
must be able to stand seining and han-
dling when water temperatures are high.
In Minnesota, there is a demand for
golden shiners in the summer, but the
fish are too delicate to stand normal
handling in warm water ; consequently,
the golden shiner is raised only for the
use of winter fishermen. While it is
possible for the dealers to use special
methods of handling the shiners during
warm weather, the fisherman is still con-
fronted with a delicate minnow that re-
quires special treatment in the minnow
pail.

7. What special handling do the fish
require? Bait fishes raised for winter
fishing require special holding facilities
and suitable food for several months.

TYPES OF PONDS

A practical hatchery can be oper-
ated with either natural or artificial
ponds — the choice depends to a
la.rge extent on the location of the
hatchery. Artificial ponds are ex-
pensive to build on sand and gravel
soils and are rarely profitable be-
cause of the added costs of ferti-
lizing and pumping. Fortunately,

ESTABLISHING THE HATCHERY

such areas usually abound in nat-
ural ponds that can be leased for a
small fee and will be cheap to
operate. Even though the yield
from natural ponds is less than
from artificial ponds, the margin
of profit may be higher. On the
other hand, in areas of heavy clay
soils, pond construction may be
fairly cheap. On such soils, nat-
ural ponds are usually scarce.
While artificial ponds on clay soils
may require heavy fertilizing, the
production Avill be high enough to
provide a reasonable profit.

ARTIFICIAL PONDS

Artificial ponds for the produc-
tion of minnows may be divided
into two categories : Single ponds,
such as those which utilize runojff
from the surrounding land, and a
series of ponds supplied by a much
larger source of water and main-

tained for large-scale production of
bait fishes (fig. 1). There will, of
course, be differences in design for
each job, depending on local condi-
tions, so that only general recom-
mendations on construction can be
made. Wherever possible, the serv-
ices of an enginer or of someone ex-
perienced in the construction of fish
ponds should be employed, to make
the best possible use of the water
supply, particularly if the construc-
tion job involves a large investment.
Regardless of size, location, or
number of ponds built, there are
four essential requirements for suc-
cess in operating the ponds.

1. The water supply must be dependa-
ble at all seasons of the year, and of suflS-
cient amount to exceed all requirements.

2. The pond should be constructed on
soil that will hold water.

3. Where a series of ponds is built,
construction should, If at all possible, be
such that each pond can be handled in-
dependently of the others.

Figure 1. — Series of ponds used in large-scale production of bait fishes. (Photo-
graph courtesy of the Ohio Department of Conservation and Natural Resources.)

WATER SUPPLY

4. Ponds should be constructed in such
a way that they can be drained com-
pletely, emptied of fish, and refilled
when necessary.

Water supply

A suitable and an adequate water
supply is of primary importance,
and should be considered first in
selecting a site for rearing ponds.
To be suitable, the water should be
only moderately hard and should
contain no other species of fish ; the
temperature of the water should be
high enough to promote rapid
growth (see p. 69) ; the pH, or hy-
drogen-ion content, should be
slightly on the alkaline side.

Springs and artesian wells are
the most desirable source of supply
because such water is dependable,
easily controlled, permanently clear,
and generally free from pollution.
A water supply should be protected
from contamination by surface
water, which may cause the supply
to become turbid or polluted by
drainage from stables, yard ponds,
and like sources, as well as from con-
tamination iby insecticides, fungi-
cides, and herbicides.

Hard water may be undesirable
because it generally contains nox-
ious gases, such as carbon dioxide,
nitrogen, hydrogen sulfide, and
marsh gas. All of these gases are
injurious to fish by actually poison-
ing or asphyxiating them. Other
waters may contain excessive quan-
tities of iron. In nearly all of
these instances, the water can be
purified and made suitable for fish
by running it over a series of falls.

or baffles, and by storing it in a
reservoir with a large surface area
to permit thorough aeration.

Spring and artesian water should
be tested beforehand by placing
fish in it. A temporary pond or
trough may be employed for the
purpose. If possible, the fish
should be held in the pond or
trough for a whole season to ob-
tain a good test ; however, a shorter
period, perhaps a month, may be
sufficient. If the fish remain
alive, the water can be considered
suitable.

Permanent construction should
include a reservoir at or below the
spring itself. This reservoir may
be of concrete, or riprapped with
stone or brick for protection. A
way must be provided so that ex-
cess w^ater from the supply can
be diverted around the pond or
ponds. A sufficient flow should be
provided to compensate for seep-
age and evaporation from the
ponds during the propagation
season.

Natural w^ater supplies, such as
creeks, lakes, rivers, or ponds, may
be utilized as a source of water,
but should be considered only
when springs or artesian supplies
are not available, or where the nat-
ural sources have all the necessary
attributes of a good w^ater supply.
These sources are subject to change
in volume, temperature, and tur-
bidity, and may be polluted. In
addition, they generally contain
undesirable species of fish which
prey on minnows and reduce pro-
duction in the ponds. No hatch-

ESTABLISHING THE HATCHERY

ery operator has successfully
screened undesirable fishes from
ponds, except by using expensive
and elaborate gravel filters.

In selecting a stream to provide
water for rearing ponds, one should
take into consideration, primarily,
the fluctuations in volume and- the
amount of turbidity. Turbidity is
particularly important because ex-
cessive silt may gradually fill the
ponds to which the water is sup-
plied. Turbid water also reduces
productivity by restricting light
penetration and, as a consequence,
the development of food organisms.
Where turbidity is periodic and of
short duration, the water should be
bypassed downstream.

The volume of water must be kept
within certain limits throughout
the year, depending on the num-
ber of ponds operated. Fortu-
nately, by building proper struc-
tures, a suitable volume of water can
be obtained. If the stream flow is
constant or if the fluctuation in vol-
ume is within narrow limits, suf-
ficient water may be obtained by the
building of a low dam (fig. 2).

This dam should be located so
that water can be obtained for the
ponds by gravity flow. The water

control structure should be of con-
crete and equipped at one side with
an intake box from which the de-
sired amount of water may be ob-
tained for the pond system. Dams
of low head provide no obstacle to
flood wa.ters and allow debris to
pass over readily without obstruct-
ing flow. Where the flow is inter-
mittent or becomes considerably
reduced during the dry season, it
may be necessary to make a larger
impoundment by constructing a
higher dam.

The dam should be anchored in
both banks of the stream with
bulkheads as high as the banks —
to protect the banks. The spill-
way should be built somewhat lower
than the bulkheads. A concrete
apron should be provided to keep
the water flowing over the spillway
from undercutting the dam. The
intake box should be provided with
a coarse grating to obstruct large
masses of debris. It should have a
slot in which a fine screen is in-
serted to keep out leaves and mate-
rials that might obstruct the flow
of water through the pipe to the
pond and to keep out other fishes.
So that the screen may be kept clear
of debris without too much diffi-

FiGURE 2. — A low dam with outlet for supplying water to ponds.

POND SITE

culty, the screening surface should
be large in proportion to the amount
of water used.

Where there is considerable de-
bris in the water, the operator may
have difficulty in keeping the screens
clean. In this situation, another
type of construction is often used.
This involves building a concrete
box in the bottom of the stream;
the box is slightly raised from the
bottom so that it does not become
covered with gravel, and so that the
current continually washes over the
surface and carries away leaves and
other debris. Information concern-
ing a structure designed along these
lines is obtainable from a qualified
civil engineer.

Where water cannot be obtained
by gravity, pumping is sometimes
justified. The pumping cost is a
continuing and constant one, and
operations must be on a scale large
enough to justify it. It is essen-
tial to have a cheap source of power.
To make operations as thrifty as
possible, the ponds must be tight
enough to prevent too great a loss
from seepage. Some operators ar-
range construction in such a way
that when one pond is being drained
a portion of the water can be di-
rected into an empty pond and
used again. This saves pumping
costs and fertilizer.

Where a series of ponds is oper-
ated, the most satisfactory results
are obtained by storing the water in
a reservoir from which it may be
taken as required. Generally, such
a reservoir is constructed by build-
ing an earthen dike just below the

source of water. This has the ad-
vanta.ges of providing an adequate
source of water as needed and of
removing noxious gases or minerals
by aeration and storage.

Water may be forced to a higher
level by means of a ram if conditions
are satisfactory for its operation.
When the source of water is a
spring, it must have a large capacity
to justify the use of a ram, which
is wasteful of water. A maximum
of about one-seventh of the water
can be forced upgrade. A 1-foot
fall from the spring to the ram is
required for every 10 feet that the
water must be forced vertically to
the pond, and the flow is further re-
duced in proportion to the horizon-
tal distance the water must be
pushed. A large reservoir that per-
mits the use of water in the pond
system, as necessary, is preferable
to having a ram supply the ponds.
Usually, obtaining water by use of
u ram is inadequate and unsatisfac-
tory.

A windmill can be used to supply
water to small ponds of i/i to 14
acre. Local conditions, such as the
amount of rainfall and evaporation,
help to determine the size of pond
tliat can be tilled and maintained by
this method. The size of the pump-
ing equipment and other elements
involved in windmill operation will
assist in deciding whether a wind-
mill should be used.

Choosing the pond site

Too much emphasis cannot be
placed on the proper location of
ponds. The selection of a good site

ESTABLISHING THE HATCHERY

results in economical construction
and satisfactory operation. Time
spent in surveying possible sites be-
fore a final selection has been made
will pay dividends. Many failures
are traceable to a compromise in de-
sign features because of the cost dif-
ficulties involved. Selection of a
site on which favorable conditions
can be utilized will avoid excessive
costs and impractical installations.

After a suitable water supply has
been located, other details of site
selection may be considered. The
area must be relatively flat and large
enough to include the ponds, build-
ings, and other structures required
for a modern hatchery. The ground
should slope gently from the upper
end of the site, which is below the
source of water, to the lower end,
where water is drained from the in-
dividual ponds into a convenient
watercourse. The main objective is
to select a site of suitable size for an-
ticipated need and of such topog-
raphy that ponds can be constructed
without moving or hauling an ex-
cessive amount of dirt too far. Any
good engineer can make a topo-
graphic survey to determine the
feasibility of constructing a pond
system on a piece of land.

The most satisfactory ponds are
constructed on impervious soil.
Clay soils or soils with a high clay
content are most desirable. The
best material consists of approxi-
mately two-thirds sand and one-
third clay, but generally some com-
promise in quality has to be made.
It is good practice to have the soil
tested. If there is any doubt as to

the porosity of the soil structure,
borings should be made to deter-
mine the depth of the impervious
layer. Care should be taken that
there are no rock strata reaching the
surface or beds of gravel anywhere
in the pond bottom, as water follows
these formations readily with con-
siderable loss to the pond.

Where an extensive pond system
is not desired, small impoundments
for the propagation of minnows
may be located in an area much
more restricted than a hatchery-
pond system would require. These
ponds may be located in a natural
gully where the land slopes from
three directions into the pond area
and where the dam will be neither
so long nor so high that the cost of
construction will be excessive (fig.
3). The shape of such a pond de-
pends entirely on the topography.

It is not desirable under any cir-
cumstances to dam a stream to make
a pond, or to locate the pond where
it is subject to regular floods. The
best impoundments are supplied by
just-sufficient spring water to main-
tain the pond level, or are located
high enough on the drainage basin
that the water level is maintained
by runofl^ from surrounding land.

In sections of the country where
rainfall is relatively high, as in the
Gulf States as far west as Louisi-
ana, the drainage area should be
about 5 acres for each acre-foot of
water in the pond. In those sec-
tions where rainfall is lower — as in
southeastern AVisconsin and south-
ern, central, and western Minne-
sota— the proportion of drainage

8

POND CONSTRUCTION

FiGUBE 3. — Pond located in a natural gully, using runoff as a source of water.
(Photograph courtesy of the U. S. Department of Agriculture.)

area should be greater. It is par-
ticularly desirable that drainage be
from good pastureland, a stable for-
est area, or other well-covered land.
Eroded or improperly tilled soils
allow rapid runoff, which results
in silty waters and gradual filling
of the pond. Some operators who
must take waters from tilled land
construct a small settling pond or
silt basin above the regular pond.
The lower end of the pond site
should be of sufficient width to pro-
vide an adequate auxiliary spillway
to carry off occasional floodwaters
(fig. 4).

Pond construction

The da/in. — Small impoundments
are generally made by building a
dam across a narrow gully where
the banks are of sufficient height to
provide water deep enough for fish
(luring winter. The depth at the
dam should be from 5 to 15 feet, de-
pending on the severity of winter
weather and the topography of the
pond bottom. In northern Illinois,
the depth should be at least 10 feet;
the farther north the pond, the more
this figure should be increased.

First consideration is given to

POND

BAD

Figure 4. — A spillway with a flat design, as on the right, is less likely to wash out
when heavy rains come than is the badly designed, V-shaped spillway on the left.

ESTABLISHING THE HATCHERY

laying out the dam and outlining
the confines of the water level in the
pond. Because of the acreages of
water impounded, earthen dams are
used almost exclusively. Deter-
mining the desirable top width is
the first step in the design of the
dam. Generally, the top of the dam
is 8 feet wide, but if it is to be used
as a road for automobile travel, it
should be at least 11 feet wide. The
equipment to be used in construct-
ing the dam also influences the
width of the top. If teams are used,
the top of the dam should be 5 feet
wide ; if tractors, a width of at least
10 feet is required. When the
height of the dam and width of the
top are determined, the base can be
laid out.

Ordinarily, the upstream, or
pond, side of the dam is sloped at
tlie rate of 3 feet for each 1 foot of
height. On the downstream side,
the slope is generally 2 to 1. If the
soil contains more than the recom-
mended amount of sand or gravel,
however, the slope should be in-
creased to as much as 5 to 1, de-
pending on the nature of the con-
struction materials used. This
simply means that if the top of the
dam is 8 feet wide and the height is
10 feet, the base will be 78 feet wnde.

Tlie site of the crest of the dam
should be laid out first, then stakes
set along the inside and outside toes,
or limits, of the dam. Stakes
should also indicate the limits of
the water level in the pond. The
dam should be high enough-to allow
2 to 8 feet of freeboard ; that is, the
top should be 2 or 8 feet above the

normal water level of the pond
(fig. 5).

All trees and bushes should then
be removed from the dam site or
stacked and burned. All stumps
sliould be removed from the pond
site, particularly if the pond is to
be drained for the removal of min-
nows, in which case it is also desira-
ble to grade the bottom so that no
low spots or water pockets will be
left after the pond has been drained.
Every piece of root or stump should
be removed from the site where the
dam is to be located. If this is not
done, the decaying wood may cause
trouble.

The next step in construction of
the dam is to form a tight bond be-
tween the dam and the base on
which the dam rests. If the surface
is covered with a layer of organic
matter, it should be removed and
stored for later use in covering sec-
tions of the dam which will be
seeded with vegetation. The area
covered by the base of the dam
should then be plow'ed.

No structure is better than its
foundation. To assure a good pond,
a section of earth should be re-
moved, parallel to and directly un-
der what will be the highest part of
(he dam, down to solid, mineral soil.
If clay soils are underlaid witli
sand or gravel, do not dig through
the clay into the sand, or the pond
will leak. Excavation for the clay
core may be accomplished with
('(piipment commonly used, but un-
der certain conditions may he done
more rapidly with dynamite.
Dynamite is particularly efl'ective

10

POND CONSTRUCTION

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11

ESTABLISHING THE HATCHERY

where the earth is saturated with
water — the wetter, the better — and
where it would be impossible to use
other methods. Holes, 12 to 20
inches apart, should be driven down
to solid earth (rarely more than 16
inches below the surface). These
holes should be charjjed with dyna-
mite made of 50-percent nitro-
glycerine, and set off \vith an elec-
tric battery to obtain the greatest
possible lifting power. The "prop-
agation" method may be used where
the soil is very wet. By this
method, one cap is used to set off
the first stick of dynamite, and the
other sticks are exploded by the
shock of the first charge. If the
soil is not Avet, a cap should be used
for each charge. Less time is
needed to construct a ditch in this
way than is required for other
methods.

By now the soil types should be
known Avith some degree of ac-
curacy. Only pure clay or clay
soils should be used to fill the trench
that has been excavated. This cut-
off wall, or core, shoidd be built up
several feet through the center of
the dam. The better, more im-
I)ervious soils tliat are available for
construction should be used directly
under the center of the dam and on
the upstream side. IjCSs desirable
or lower quality earths, such as
sand, stone, or gravel may be used
in the fill, hut they should be in-
corjK^rated only on the downstream
side of the liighest [)oint in the dam
and extend to the toe. So placed,
these poorei- earths provide weight
to prevent slipping and are at the

maximum distance from the satura-
tion point of the water.

With small dams or pure clay
soil, it is unnecessary to construct
a core through the dam. The same
result may be effected, after the
whole area of the base is plowed, by
removing the topsoil down to solid
earth on the upstream half of the
dam and properly placing it on the
lower half. The solid earth should
then be plowed so it will bind with
new earth moved in. Thereafter,
the builder should follow the
same construction procedure rec-
ommended for a dam in which a
core is made.

After the base has been properly
prepared, the drain line should be
laid. A shallow excavation to solid
earth should be dug from the pro-
posed pond outlet to a point below
the dam. Earth, the best clay avail-
able, should be firmly packed
around the pipe, particularly on the
underside. Addition of water to
the soil to form a stiff mud will fa-
cilitate a firmer pack in the tamp-
ing process. At some central point
in the dam, a concrete collar should
be poured around the pipe. This
prevents water from following the
pipe and developing leaks; it also
prevents burrowing animals, such
as crayfish, from following the
pipe. After the pipeline has been
set up, construction of the dam may
go forward.

Earth from somewhere within
the pond area can be used to pro-
vide dirt for the dam. Most of the
soil should be obtained in the vi-
cinity to save labor. The whole

12

POND CONSTRUCTION

bottom area of the pond should be
deepened and graded to drain prop-
erly, and soil removed from all the
pond edges so that the water has a
minimum depth of approximately
2 feet. Earth taken from the edges
and not used in the dam may be
used for sloping the bottom of the
pond so it will drain properly.

Earth can be properly placed on
the fill by keeping the fill higher
on the edges than in the middle.
If this is done, there will be no
tendency for equipment to spill
over and earth can be dumped the
proper distance from the edge.
Dirt should first be dumped about
2 feet from the upstream, or inside
toe, stakes and about 18 inches from
the lower, or downstream, stakes.
This procedure will save labor by
making a natural slope. Con-
versely, all cuts with the scraper
should be made deeper at the edges
than at the center. This prevents
the equipment from sliding away
from the banks, a possibility which
might result in a ragged slope.

Fill placed on the dam should be
properly compacted. Maximum
compaction is effected by putting
earth in place in thin layers and
traveling the full length of the fill
each time. On high dams, special
compacting equipment, such as a
sheepsfoot roller, is needed, and the
required density is obtained by the
control of moisture content. Al-
though the compacting reduces the
amount of settling, allowance
should always be made for it.

The actual process of construct-
ing a series of hatchery ponds is

somewhat different from building
a dam, but the method of placing
and compacting the material is the
same. The slopes on the dikes be-
tween the ponds should be uni-
formly 2 to 1. Where there is a
series of ponds, it will be necessary
to make only the dams or levee on
the outside of the series water-tight
by using a clay core. All levee bases
should be properly prepared by
clearing off organic debris and plow-
ing the entire area.

The design of a hatchery is de-
pendent on the size, shape, and
topography of the land on which
it is located. If the plot of land
is properly sloped, ponds may be
planned in such a way that suf-
ficient earth can be removed from
the pond site for the embankments.
Ideally, the ponds should be from
1/4 to 1 acre in n^ea, but the topog-
raphy of the land will dictate, to
some extent, the size of pond that
can be constructed most economi-
cally. Under no circumstances
should there be any large number
of ponds of an acre or more in size.
Small ponds are handled more eas-
ily and are generally more pro-
ductive (fig. 1).

Plans for excavation and for the
placement of drains and waterlines
should be made by a competent en-
gineer. All elevation stakes for
drain and waterlines and for the
dikes should be placed before exca-
vation starts. The drainage lines
are generally placed in or through
the levees so that it is essential to
have these lines in place before pond
construction starts. The drainage

367913 0—56-

13

ESTABLISHING THE HATCHERY

lines always lead from the deepest
part of the pond to a convenient
watercourse that will carry off the
drainage water.

Ponds should be so constructed
that the minim\im depth at the
shallow end is about 2 feet. Ponds
to be used for propa<ration purposes
should be sloped so that they are at
least 5 to 6 feet deep at the outlet.
Ponds used for holding fish through
the winter must be at least 10 to 12
feet deep in the Northern States;
however, the size of the pond will,
to some extent, determine the depth
at the outlet.

The pond bottom should be sloped
from the sides and ends toward the
center and the center sloped from
the shallow end to the outlet. The
grade through the centerline of the
pond should be not less than 1 foot
for each 100 feet of pond length.
Where a series of hatchery ponds
is being constructed, the ponds are
partly above and partly below nat-
ural ground level.

The type of equipment most
economical to use for excavating
a series of ponds depends on the
size of the job and the distance
that earth must be moved. Horse-
drawn equipment is economical
only for small jobs and short
hauls, but may be used for larger
jobs if it is the only equipment
available. With horses, a slip
scraper may be used economically
for moving earth as much as 50
feet, but for distances of more
than 150 feet the cost is' so great
that some other type of equipment
should be considered. If horses

are used for longer distances, a
four-horse-loaded, two-horse-trans-
port wheeler should be used.

Maximum efficiency may be ob-
tained with a 35-dhp (D-4) trac-
tor bulldozer at distances from 100
to 150 feet and where the grade
is not more than 5 percent. As
the grade increases, the efficiency
of a bulldozer decreases rapidly.
A self-loading, c a r r y i n g-type
scraper should be used at distances
greater than 150 feet. On larger
jobs, or where hauls are more than
500 feet, a 11-3-dhp tracktype trac-
tor is more economical. Of course,
availability of equipment may be
the decisive factor in most cases.

Structures. — The types of struc-
tures to be used in conjunction
with hatchery layouts are largely
a matter of preference, but experi-
ence has shown that adequate con-
struction is highly advantageous.
Likewise, experience has demon-
strated that adequate construction
is more economical than skimping
on sizes and materials. Thus, pipe-
lines of sufficient size are more eco-
nomical than pipelines that are too
small. In the past, tile drainlines,
caulked with cement, have been
used extensively because the origi-
nal construction cost is lower. Un-
fortunately, there have been many
failures with these lines on ac-
count of loose caulking, entrance
of tree roots, pressure from the
fill, and for other I'easons.

Great advances have been made
in the last few years in pipeline
fabrication. Among the types re-
cently developed, the most suitable

14

POND CONSTRUCTION

for use as outlets and tlie most
easily installed are spiral-welded
steel pipe and asbestos-cement cast
pipe. Spiral-welded pipe is light-
weifjht, lontj lasting if properly
installed, and comes in long
lengths. Asbestos-c e m e n t pipe
comes in shorter lengths but can
be cut with a saw, and the joints
have considerable flexibility. Not
subject to corrosion, its period of
utility is indefinite. Standard fit-
tings can be used with both kinds
of pipe, and they can be utilized
for both drainage and waterlines.
In ponds i/4 ^^^'^ or less in area,
the drainline should be not less than
0 inches in diameter; and in ponds
of 1/4 to 114 acres, the line should
be not less than 8 inches. Use of
large drainlines has a number of
advantages, including savings in
time and labor and frequently a
saving in fish (which may be lost
otherwise because of high temper-

ature, suffocation, muddy water,
or other causes, in the draining
process).

Every pond should be equipped
with an outlet structure of some
type. This outlet, or kettle, serves
a number of purposes. It acts
as an o\'erflow Avhen rain or other
inflow of water raises the pond
level above normal. In the proc-
ess of draining the pond, the out-
let holds back the fish so that they
can be removed when the water
level has fallen to a depth that the
operator can wade.

In small impoundments which
are to be drained infrequently, one
of a number of outlets may be
used. The Canfield outlet is the
type most commonly used (fig. 6).
It consists merely of a pipe cut
to the proper length so that it will
act as an overflow and control the
pond level. This pipe is inserted
in a 90° ell attached to the drain-

WoUr Surfoce

e

Pischarc^t P>pc

Figure 6. — Canfield pond outlet. Commonly used in small impoundments that are

drained infrequently.

15

ESTABLISHING THE HATCHERY

line and can be tipped to the de-
sired level to drain the pond.

Another outlet is merely a cement
block laid around the outlet pipe,
attached to which is one of a num-
ber of gates ( fig. 7 ) . The most com-
monly used gate is the usual irriga-
tion gate, the cost of which wnll
vary according to size and type
used. A homemade gate can be
made by bolting a channel iron to
the block on either side of the open-
ing and inserting a piece of boiler
plate that fits over the opening and
has a handle welded on it (fig. 8).
It can be made by a blacksmith.

Eesearch workere at Alabama
Polytechnic Institute, Auburn,
Ala., have designed an inexpensive
gate which is attached to the bell of
a piece of soil pipe. They recom-

mend an adaptation which is at-
tached to a 30° ell so that the gate
can be opened by pulling a wire on
shore. This arrangement eliminates
the need for a platform to the out-
let, which must be located in the
pond beyond the toe of the levee and
at the low^est point in the bottom.
If the pond is to be drained fre-
quently, however, one of the stand-
ard outlets for hatchery ponds
should be used.

Hatchery ponds should be
equipped with an outlet to permit
ready drainage and removal of the
fish that have been propagated.
There are two general types of out-
lets which may be adapted to con-
ditions. One type has the outlet
and water-control structure inside
the pond and the catch basin for

Ovirflow slandpip*
if dasired •— ^

^

-^i^ —

\^^^

W

\

y

Q

? I

J

-IM

■ N

t

< A- n )

k

Figure 7. — Cement-block pond outlet.

16

POND CONSTRUCTION

Gole Lif4

4

OUD

4i>

<y^

Anclior

^^Dischorqe Pip?

ss^^^^^^

^S!

GaU Plo4«

^^S^^^

Z"^2"An<^i« Iron l^l Anqle Iron

Figure 8. — An inexpensive pond outlet gate that can be made from materials on hand.

collecting fish outside (fig. 9) . The
other has the outlet kettle and catch
basin inside the pond.

The plan of a conventional type
of catch basin and outlet is shown
in figure 10. Built of concrete, this
structure makes it possible to con-
trol the water level and to drain
the pond. The outlet is at the low
point in the bottom of the pond,
usually midway of one side. The
catch basin should extend 6 to 10
inches above the bottom of the pond.

The chimney usually has two sets
of slots. The outer slots are pro-
vided for a screen (.4), which pre-
vents fish from leaving the pond
and debris from entering the pipe-
line. The screen is made of hard-
ware cloth on a wooden frame which
fits into the slots. The screen may
be as fine as 8 meshes to the inch
or as coarse as 4, depending on the
use to which it will be put.

The second set of slots is for
dam boards, or stoplogs, which are

17

ESTABLISHING THE HATCHERY

FiGURK 9. — Catch basin constructed outside the pond.

usually made of 2-inch by 8- or
10-inch treated, finished lumber,
and beveled on either end to fit.
The boards are placed one over the
other up to the desired water level
in the pond, and they serve as aji
overflow where rainfall or other
water may raise the pond above the
desired level. These boards may
be kept ti<j:ht by snuill wedges in-
serted at either end of the upper
board.

The type of construction used is
a matter of |)reference. The solid
wall i)rovides a tight outlet with
an ea.sily manijmlated outlet gate.
On the other hand, the dam boards.

or stoplogs, can be removed at will
and the water level kept at any de-
sired point in the pond. Also, if
an irrigation or other gate is used,
the total pressure of the water is
against the screen when the pond
is being drained, a.nd should the
gate become blocked with debris
(as is generally the case) , the screen
may be broken. If dam boards
are used, they are removed one at
a time and the pressure is only tht
depth of the flow over the board;
c()nse(iuently, the screens seldom be-
come entirely blocked and are never
broken by pressure; also, there is

18

POND CONSTRUCTION

no loss of fish from their being
forced against the screen.

The kettle, or catch basin, which
is attached to every outlet .box,
should be about 10 to 18 inches deep,
and should extend above the bot-

tom of the pond. Experience has
shown that most of the fish can be
removed with a seine as the water
is being drained, but some recep-
tacle should be provided to capture
the last few fish. The catch basin

MH

SECTION THROUGH
CENTERLINE

MEASURE

MENTS 1

POND ACREAGE

A

C

I

J

K

L

0

R

S

^OR LESS

3(5

6"

I'/;

6"

iv;

6"

6"

10'

6'

'/z-l'/z

36

6*

1'//

6"

i'4"

6"

af

12'

6'

2-3

42

6-

2"

6"

2"

6'

id

14'

8'

4-8

48

8"

2'4

6"

2VJ

6"

\Z

16'

8'

10- 15

54

8

3"

6*

3'

6"

15

18'

10

Figure 10. — Plan of catch ba.sin with sutigested lueasurements for the viiU-h ha.siii

according to size of the pond.

19

ESTABLISHING THE HATCHERY

and outlet combination should be
set at the toe of the levee and half-
way down one side of the pond at
the deepest end.

An alternative type of construc-
tion involves the use of an outlet
box and the catch basin at some
point outside the pond (fig. 9).
The outlet box is similar to that
designed for a natural pond and
does not require the use of a screen.
All the water is drained through
the outlet to a catch basin outside
the pond.

The outside seining, or catch,
basin is a concrete tank constructed
in such a way that water from the
pond outlet flows into it. Grooves
are provided for a screen and dam
boards. "Where the outlet from the
pond comes into the seining basin,
it is provided with an irrigation
gate or valve which may be shut
when desired.

Most of the water from the pond
is drawn through the seining basin
until a considerable number of min-
nows come into it from the pond.
The outlet valve to the pond is
closed and the water in the basin
lowered until the majority of the
minnows can be removed to suitable
receptacles. This operation is re-
peated until all the water has been
drained from the pond and all the
minnows have been removed from
the seining basin and placed in
holding facilities.

The type of construction with
ponds in a series along a water-
course or grouped in such a way
that a number of pond outlets can
bo brought into the seining basin

is most economical, because more
than one pond can be drained into
the basin. If there is a large group
of ponds, the situation may not lend
itself to this type of construction,
because only one pond can be
drained at a time. Where there is
a basin in each pond, more than one
pond can be drained at a time —
often a very desirable procedure.

Waterlines supplying the ponds
should be of sufficient size to fill the
ponds rapidly and to maintain
water levels. At least 4-inch, and
preferably 6-inch, pipes should be
run to each 1-acre pond. The main
supply lines from which these pipes
lead off should be designed in ac-
cordance with the number of ponds
supplied, the amount of water pres-
sure, and other factors. Cements-
asbestos pipe is ideal for the main
supply lines. These lines should be
laid in the dikes at the proper stage
of construction.

There is some difference of opin-
ion regarding the proper location
of the water-supply lines to the in-
dividual ponds. Where the seining,
or catch, basin is located in the
pond, the supply line should be lo-
cated at the basin. This permits the
use of fresh water when the pond is
being drained and when the pond
water is muddy from frequent agi-
tation. It also provides a source of
fresh water to fill receptacles used
to transport fish from the pond.
Except in those ponds used for the
l)ropagation of stream-breeding
species such as the creek chub, there
seems little in favor of having the
water supply at the end opposite the
outlet.

20

NATURAL PONDS

NATURAL PONDS

In some localities, the bait dealer
will have to use natural ponds for
the production of minnows because
of the lack of suitable locations for
artificial ponds. While natural
ponds often do not produce as many
minnows to the acre as do artificial
ponds, there are some points in their
favor. Natural ponds do not re-
quire expensive dams and control
structures, rentals are usually low,
and little or no fertilizer is needed.
As these factors add up to low pro-
duction costs, the margin of profit
is usually high.

Natural ponds available for the
production of minnows vary
greatly in size and shape, but me-
dium-sized ponds are most practical
to operate. Large ponds are too
difficult to seine and small ponds
cost more per acre to seine than do
medium-sized ponds. Deep ponds
produce better in hot, dry years
when shallow ponds become too
warm and may even dry up, but in
cold, wet years, the shallow ponds
come into their own. As it is diffi-
cult to predict a full season of
weather, the dealer should try to
operate both shallow and deep
ponds each year. While the type of
pond most practical for production
varies with the species of minnow
to be raised, Minnesota dealers have
found that natural ponds 3 to 5
acres in size and 5 to 8 feet deep are
most profitable.

Natural ponds vary greatly in
fertility. Ponds located in rich
farmland are usually very fertile.

and ponds on poor, rocky soils are
infertile unless the runoff includes
such sources of fertility as barn-
yard drainage. The type of soil on
the pond bottom has a definite effect
on pond fertility. Fine-textured
soils that cloud the water easily and
give up their fertility readily are
usually found in fertile ponds.
Soils that have most of their fer-
tility tied up in vegetation or or-
ganic matter give up that fertility
very slowly and ponds with such
soils tend to be moderately fertile.
The relative fertility of a pond can
be judged by how green it becomes
during hot weather: the greener
tlie water, the richer the pond.

A rich pond will contain a large
amount of nutrients in the water
and will produce good crops of wa-
ter fleas for fish food at various
times during the season. Such a
condition is desirable for the pro-
duction of large fish crops, but rich
ponds also may produce great
amounts of algae. P]ven though al-
gae enter into the food chain, these
microscopic plants are not readily
eaten by most minnows, and when
they decompose the dissolved oxy-
gen in the water is used up and
large amounts of ammonia are pro-
duced. The fish need a fairly high
concentration of oxygen for respira-
tion, and ammonia in large concen-
trations is toxic to them. Conse-
quently, the decomposition of a
heavy algal growth may kill a large
number of fish. Algal blooms are
likely to be more harmful in shallow
ponds than in deep ponds. Some
species of minnows tolerate lower

21

ESTABLISHING THE HATCHERY

oxygen and liigher ammonia concen-
trations than others and are, there-
fore, more successful in fertile
ponds. Each species has its limits
of tolerance that cannot be exceeded
if the production of a pond is to be
profitable.

The productivity of a pond is also
related to the hardness of the water.
Medium-hard to very-hard water
will usually produce more fish than
soft water. Sometimes it is possible
to increase the hardness of the water
by the addition of lime, but fish pro-
duction will not increase unless the
water contains sufficient nutrients,
or a sufficient amount of these ele-
ments is added with the lime.

Seining conditions in natural
ponds must be considered before the
pond is selected. While it is pos-
sible to trap minnows, they often
do not move into the traps when
needed, and seines must be used to
get them out in time for the market.
A pond with boggy shores, steep

banks, soft bottoms, or brushy edges
should be avoided unless it has an
open, firm-bottomed beach for good
seine landings.

Fertile ponds covered with ice
and snow will often run out of oxy-
gen before spring, and the fish will
smother unless the pond is at least
15 feet deep. During winters of no
snow, the ice will transmit enough
light to keep the plants in the pond
actively supplying oxygen and the
fish may survive in quite shallow-
ponds. During winters of early
and heavy snow-s, fish will survive
if the ice is kept clear of snow. Be-
cause of the difficulties encountered
in holding minnows over winter in
natural ponds, most dealers plan
their production so that all minnows
can be sold the first year. When
this is not possible, holding ponds
with running water are used and the
fish are fed artificially through the
winter.

22

CHOOSING THE FISH

Many factors must be considered
in choosino; a bait species to be
raised. Several species should be
reared if the dealer expects a sus-
tained income from his operations.
If properly selected, they will pro-
vide suitable sizes through most of
the year. As a general rule, a be-
ginner should raise only one species
in each pond.

The following characteristics
should be considered in selecting a
bait species for propagation :

a. The fish should be reasonably
tolerant to seining, handling, and
transporting.

b. The fish should have a rapid rate of
growth. Even then, some species must
be held more than one winter in northern
latitudes.

c. The adults must be large enough to
be suitable bait for the predominant game
fish of the region.

d. The species should have an extended
spawning season.

e. The fish should be prolific.

f. The fish should not be excessively
cannibalistic.

g. The fish should be resistant to the
more virulent fish diseases.

h. Those species lacking spines and
hard parts are most suitable.

i. The minnow should be one that
thrives under cultivation.

j. The fish should be suited to the ponds
available.

k. Holding qualities are of the utmost
importance.

1. Species that are hardy on the hook
sell the best.

None of the bait species will meet
all of these conditions, but all the
points should be considered when
choosing a species of fish to raise.
Often popular demand will dictate
the kinds that can be sold. Among
the most popular bait fishes for
propagation are the sucker, golden
shiner, creek chub, fathead minnow,
and goldfish ; and specific informa-
tion relative to their production is
given in the section on Some Impor-
tant Bait Fishes, pp. 68-102.

23

OPERATING THE HATCHERY

FERTILIZING THE POND

The object of fertilizing a pond
is to produce foods in large quan-
tities at the time they are needed
most by the fish. Several methods
of supplying fish foods are in use
at the present time. In the North-
ern States, organic fertilizers are
added to the pond to produce a
growth of bacteria and protozoa
(fig. 11). These small forms are
food for the waterfleas and rotifers,
which in turn are the main source of
food of the important bait fishes.
In most Southern States, the ponds
are fertilized with inorganic fer-
tilizers, which release nitrogen and
phosphorus into the water. Mi-
nute plants (algae) which often
give a greenish color, or bloom, to
pond waters utilize this nitrogen
and phosphorus. When they die
and decay the food stored in them
becomes available to minute ani-
mals (i)rotozoa) in the water.
These anima.ls are food for the wat-
erfleas and rotifers. The food cycle
with algae in the primary stage is
dangerous to use in northern ponds
because of the danger of an excessive
algal growth, which uses such a
large amount of oxygen from the
water when it decomposes that the
fish suffocate.

A third method of providing
crustacean (waterfleas) fish foods,
that is little used but offers great
possibilities, is dry fallowing. Each
pond is drained and dried up pe-
riodically. When the pond bottom
is dry enough to support farm ma-
chinery, it is disked, fertilized with
10-10-10 fertilizer, and planted to
rye. The rye is allowed to grow to
a height of 6 to 8 inches before the
pond is refilled. As the rye decom-
poses a growth of bacteria and pro-
tozoans develops. In 7 to 10 days
the pond contains a crop of water-
fleas 8 to 10 times greater than that
obtained by fertilizing. Natural
ponds maintain their fertility by a
similar process. When the pond
level is low, the exposed bottom be-
comes covered with a growth of hay.
When the pond level is high, the
hay is flooded and decomposition
starts a new food cycle.

For maximum growth of the fish
and maximum fish production, the
food chain should be started early
and should be maintained through-
out the growing season. In north-
ern ponds, barnyard manure is gen-
erally used in the spring because it
decomposes rapidly and gets the
food chain oft' to an early start.
Manure should be applied at the
rate of 400 to 1,000 pounds to an
acre of water, depending on the fer-
tility of the pond. Dried sheep

24

FERTILIZING THE POND

Figure 11. — Ponds often need to be fertilized to increase their productivity.

manure can be used at half the rate
of fresh manure. The proper time
of application is 2 weeks before the
pond is to be stocked so that a
heavy food crop is ready for the
fish.

During the growing season, the
food supply is maintained by peri-
odic applications of dried sheep
manure. The applications should
be made at 2- to 3-week intervals
all summer. Ponds should be fer-
tilized at the optimum rate rather
than the maximum because an ex-
cess is a waste of fertilizer and the
decomposition of a large quantity
of fertilizer may reduce the oxygen
content of the water enough to
cause suffocation of the fish.

AVhen soft-water ponds are fer-
tilized, it will be necessary to add
agricultural limestone to the water
to maintain proper alkalinity. A

rule-of-thumb for liming ponds is
to add half as much limestone as
fertilizer.

In the Southern States, fertiliz-
ing should be started during the
first warm w^eather of spring, and
should be continued through the
summer and early fall. In the far
South it may be advisable to fer-
tilize monthly during the winter.

In fertilizing a pond, supply
enough nutrients to the water to
induce the growth of microscopic
plants, which give the water a
green or brown tinge. It is neces-
sary to apply the fertilizer fre-
quently enough to build up a sur-
plus of minerals. Applications
should be made at weekly or 10-day
intervals and should be continued
until the water becomes so turbid
(as a result of these microscopic
organisms) that the bottom cannot

25

OPERATING THE HATCHERY

be seen at a depth of more than 12
to 15 inches. Fertilizing should
then be stopped until the water be-
gins to clear, when it should be re-
sumed. The objective is to main-
tain a constant amount of turbidity
in the water. One should not over-
fertilize, as the production of too
many of certain microscopic or-
ganisms will be detrimental to the
fish by removing too much oxygen
from the water at night and on
cloudy days.

Each application of fertilizer
should consist of 100 pounds of fer-
tilizer of approximately an 8-8-4
formula for each acre of water sur-
face. This means that each 100
pounds of fertilizer contains 8
pounds of water-soluble nitrogen,
8 pounds of phosphate, and 4
pounds of potash. If fertilizer of
this formula cannot be purchased,
regular garden or farm fertilizer
may be supplemented with nitrate
of soda, ammonium nitrate, super-
phosphate, or other chemicals.
Any fertilizer dealer can give in-
formation for modifying regular
fertilizers to obtain the proper
formula. The 8-8^ formula was
first worked out by Swingle and
Smith at Alabama Polytechnic In-
stitute and is generally applicable.

There is some variation in fer-
tilizer requirements, however, ac-
cording to the chemical content of
the water. For instance, in very
hard water at the I^etown, W. Va.,
station and surrounding territory,
it was found that a 12-5-5 mixture
gave best results. In general, hard
waters require more nitrogen and

less phosphorus and soft waters less
nitrogen and more phosphorus.
Under acid conditions it may be
advisable to use lime. At the pres-
ent time, there is insufficient knowl-
edge to make specific recommenda-
tions for all conditions. One can
obtain the desired results simply by
increasing the amount of fertilizer
per application, where a "water
bloom" is not obtained within a rea-
sonable time. Generally, 6 to 12
treatments are required through the
summer, depending on the fertility
of the water, length of the season,
amount of runoff, and other condi-
tions.

STOCKING THE POND
WITH ADULT FISH

A very important step in op-
erating the pond is to stock it with
the correct number of brood fish.
Adult fish seined from streams or
lakes in the spring before they have
had time to spawn are commonly
used as brood stock. Because of the
uncertainty of the natural supply,
it is desirable for the dealer to hold
the brood stock from year to year.

When selecting fish for brood
stock, the dealer should attempt to
get an assortment of sizes. For ex-
ample, the male fathead and blunt-
nofre minnows are larger than the
females, while the male golden
shiner is smaller than the female.
If only the largest specimens are
selected, the pond will have an un-
balanced sex ratio. In certain of
the Lake States, the following rates
of stocking of adult fish have been
found satisfactory :

26

ARTIFICIAL FEEDING

Species stocked

Fish stocked
per acre

State

Reference ^

Fathead minnow

1,500

5,000

1,000

500 to 1,000 __

1,800

714

Minnesota

Ohio

Bureau of Fish Propa-

Do -

gation.
Wascko (1946).

Do

Wisconsin

Louisiana

Ohio

Hasler et al. (1946).

Golden shiner _

Viosca (1937).

Do - -

Wascko (1946).

Silvery minnow

New York

Raney (1941).

1 See Bibliography, p. 118, for publications indicated by year in parentheses.

ARTIFICIAL FEEDING

Food preferences of fish usually
vary with age. The young can
swallow only small organisms and,
therefore, feed mostly on plankton.
Adults require larger and more
substantial food. For maximum
production in ponds, minnows
should be provided with the foods
most suited to their needs and
their ages. Choice of ponds and
fertilizer can greatly affect the
type and availability of food.

The alternative to fertilizing is
artificial feeding. The usual pro-
cedure is to feed the fish all the
ground food they will eat in 2
hours. Ponds operated under ar-
tificial feeding have such large
populations of fish that food can-
not be allowed to remain longer
than 2 hours without danger to the
oxygen supply in the water. One
food formula used successfully con-
tains 15 percent of cottonseed meal
and meat scraps mixed with 85
percent of middlings. Another
formula contains 100 pounds of
beef melts, 50 pounds of dry dog
food, 50 pounds of whitefish meal,
6 pounds of salt, and water enough

to make a good feeding consist-
ency. Fifty pounds of ground,
raw carp can be substituted for 25
])ounds of fish meal. A formula
that produced large numbers of
minnows in Michigan is composed
of the following ingredients :

Poundg
Cooked cornmeal and oatmeal 275

Bone meal 200

Clam meal 400

Maggots can be provided by put-
ting fresh-meat scraps in a screen-
bottomed box, which is placed over
the pond so that the maggots fall
into the water.

Many minnow ponds produce
large numbers of crayfish from
natural stock that either migrate
into the pond or hibernate in the
])ond bottom. In many localities,
crayfish can be sold for bait, but
where there is no demand, ground
crayfish makes excellent minnow
food. Such food is usually avail-
able only in the fall when the
jionds are drained to harvest the
fish. Crayfish, ground or whole,
can be fed to the fish in winter
holding ponds, or used for ferti-
lizer on the pond bottom.

At least twice as many fish can

27

OPERATING THE HATCHERY

be raised per acre of water by ar-
tificial feeding; consequently, only
lialf as many ponds are needed to
produce a good supply of min-
nows. Though the cost of produc-
tion is higher when the fish are
fed artificially, this may be offset
by a reduction in the original cost
of the pond and in the annual
maintenance. The artificial feed-
ing of heavy fish populations
(more than 2,000 pounds of fish
per water acre) requires a con-
stant flow of water through the
pond for aeration and cleanliness.
Only a small part of the natural
pond fertility and very little of
the fertility available from the
decomposition of food wastes are
used. Such concentrated popula-
tions must be treated for disease at
frequent intervals. (See page 50).
The Michigan Institute for Fish-
eries Research has developed a com-
bination method whereby creek
chubs are artificially fed and suck-
ers are raised on the bloom pro-

duced by the decomposition of the
feeding wastes. The costs of pro-
duction were reduced under this
method.

It should be remembered that
water temperatures have a direct
effect on the amount of food eaten
by fish. In cold-water ponds, the
consumption of food is low and
growth is slow. Also, when the
water becomes excessively hot, food
consumption declines and growth
becomes slow.

HANDLING BAIT FISH

While many species of fish can
be found in the tanks of the bait
dealers, certain species are more
popular and are handled in greater
quantities. These fish require dif-
ferent methods of propagation, but
the handling techniques will be
similar for all. The following
table lists the kinds of bait fishes
in greatest demand in the Lake
States :

Species

Michi-
gan

Minne-
sota

Wiscon-
sin

Sucker _

X
X

X
X
X
X
X

X

Creek chub. _

X

Pearl dace . . _ .

Finescale dace . _

Northern red belly dace

X
X
X
X
X

X

River chub_ _ _

Golden shiner . _

X

X
X
X
X

X

Emerald shiner. .

X

Common shiner .

X

Fathead minnow . .

X

Bluntnose minnow

X

X

Western mud minnow..

X

28

HARVESTING FISH

HARVESTING FISH
Seining

Whether seining in public water
or in his own minnow pond, the bait
dealer should seine with the objec-
tive of catchino; the maximum num-
ber of fish with a minimum of loss.
The following- suggestions are pre-
sented to help the beginner avoid
undue loss.

Types of seines. — Minnow seines,
generally speaking, can be classified
into three types depending on the
kind of weave used in their con-
struction. The most common min-
now net is made of woven threads,
and with prolonged or severe use
it will develop "runs" caused by
thread breakage and separation.
This type of netting can be ob-
tained in mesh sizes of % to %
inches (bar measurement). The
second type of seining fabric is con-
structed with a nonslip knot tie.
Each mesh is individually knotted,
and it will not develop runs or
thread separation under the most
severe operating conditions. In this
type of netting, mesh sizes ranging
from 14 inch upward can be ob-
tained. The third type of netting
material used by fish culturists and
bait dealers is called, "bird's-eye,''
or bobbinet cloth. It is a fine- woven
fabric and is excellent for use in
collecting small fish (fry). The
new nylon bobbinet is much better
material for short seines than is
the old cotton "bird's-eye."

The net should be picked accord-
ing to the job to be done. A 1-acre

circular pond can be seined very
effectively with two hauls of a 200-
foot net, at depths of 6 to 12 feet.
A pond that can be drained to a
seining pool can be seined much
more easily with a 30-foot net (fig.
12). A net that is too long for the
job is cumbersome to use and in-
creases the chance of injury to the
fish. For seining in public waters,
the net should be at least of ^-
inch mesh so that the minnows too
small for use can escape for further
growth. In a small production
})ond a bobbinet seine can be used
to transfer the small fish to a win-
tering pond (fig. 13).

Good seining methods. — When
possible the seine should be landed
on a firm, sandy bottom. The silt
stirred up on a soft bottom adds to
the discomfort of the fish and may
cause suffocation. When there is
danger of suffocation, smaller hauls
should be made and the fish should
be bagged and moved to deeper
water as fast as possible (fig. 14).

When landed, the seine should
never be pulled onto the shore. As
soon as the fish are in the net, it
should be bagged loosely and floated
to deeper water. The fish should
then be dipped with a small hand
net, or scap net, into a floating live
box (wooden box with a hardware-
cloth bottom) for sorting (fig. 15).

Once in a while the bait dealer
will find it necessary to seine min-
nows in large bodies of water with
a small net during a season when
the fish are too far from shore to be
taken by the usual method. In
such a case, two or three seiners put

367913 0—56-

29

OPERATING THE HATCHERY

Figure 12. — Seining minnows from an artificial pond. Drawdown has expo.sed the
inside seining' well. (Photograph courtesy of the Michigan Department of
Conservation.)

on waders and wade out as far as smd hoist it out of the w a t e r.
possible. Two men take the seine Thouj^h the take by this method is
brailles and a third keeps the float- not large, the roiling process in-

ing live box in tow. The three men
stand with their backs together and
roil the water with their feet.
When the water has been thor-
oughly roiled for a few minutes,
two seiners back off in opposite
directions pulling the seine in a cir-
cle. By going backward, they can
travel faster than if they went for-
ward. The third man turns and
backs out of tiie way splashing the
water as he goes to drive the min-
nows into the net. AVhen the sein-
ers liave completed the circle, thev

creases the harvest as much as 8 to
10 times. (See figure 16.)

Trapping bait fish

Wire and glass traps. — Wire and
glass traps are commonly used by
minnow dealers to collect bait.
Similar in design and differing only
in construction materia.ls, both con-
sist of a pot and an entrance funnel
or funnels. The wire trap (fig. 17)
is more variable in design, being
round, rectangular, or square, and

take up the slack in the net, bag it, having from one to four funnels.

30

HARVESTING FISH

FioTTBE 13. — A bobbinet seine is used to catch the fry in a small production pond.
Good seining methods help to prevent fungused flsh. (Photograph courtesy of the
Minnesota Department of Conservation.)

Glass traps usually are round and
have only one funnel entrance.

Glass traps are used mainly in
streams. This type of collecting
gear has proved highly efficient ; not
only can a large number of minnows
be taken in a relatively short time,
but the fish can be collected with
little or no injury. Operation of a
glass trap is simple. The first step
is to follow along the banks of a
stream until a school of minnows is
located. The next step is to seek
an area upstream from the school
of minnows where the current is
weak and the water depth does not
exceed 1 foot. (These locations

are usually found near the banks of
the stream.) At this point a small
depression about the size of the glass
trap is gouged out of the bottom,
and the trap, baited with finely-
ground cracker crumbs, is placed in
the depression with the funnel open-
ing facing downstream. Within a
few minutes, by current action,
some of the food particles originally
within the trap will be drifting
downstream, attracting the fish be-
low. Immediately, the minnows
will move upstream toward the
source of the food supply ; within a
half hour, the food supply in the
trap will be exhausted and a num-

31

OPERATING THE HATCHERY

FiorRE 14. — Removing the fish from a seine in such a way as to avoid the roily water
close to the shore of a shallow pond. (Photograph courtesy of the Minnesota
Department of Conservation. )

ber of minnows will have been cap-
tured.

The minnows should be removed
from the trap as soon as the food
is gone, as experience has proved
that the mimiows will soon escape.
On one stream in Michigan, four
glass traps took a total of 600 min-
nows, 21/2 to 51/2 inches long, in 1
hour. The number of minnows
captured per trap per set ranged
from 10 to 70. The average dura-
tion of a set (established by food
depletion) was about 20 minutes.

Wire traps. — Wire traps are most
efficient when set in quiet waters
iuul attended daily. They are

baited with bread or cracker crumbs
and placed on the bottom of a
stream or pond or suspended above
the bottom at a desired depth by a
stake. The traps should be at-
tended daily and all fish removed
on each visit. If the minnows are
allowed to remain in the trap for
any extended period, many become
injured by continued contact with
the sides of the screen. In a pond
or lake where a good population of
minnows is known to exist, one \yire
trap, 2 feet long by 16 inches square
and containing a funnel at each
end, wnll take as many as 500 min-
nows in 1 day's operation.

32

HARVESTING FISH

Figure 15. — Transferring the fish from seine to floating live box. (Photograph cour-
tesy of the Minnesota Department of Conservation.)

J^

Figure 16. — Seining in deep water after the tish have been attracted to an
area of roily water. (Photograph courtesy of the Minnesota Department of
Conservation.)

33

OPERATING THE HATCHERY

^ J

%

^^^^^^

Figure 17. — Wire trap couimonly used by bait dealers. ( I'hotograph courtesy of the
Minnesota Department of Conservation. )

Artificial ponds that are difficult
to seine because of weeds or soft
bottoms can be equipped with a
wire trap at the inlet (fig. 18). By
running a current of water through
the trap, the dealer can catch the en-
tire population of a pond in 2 or
3 days.

Netting fish

Drop nets. — One of the nets fre-
quently used in harvesting minnows
from lakes and ponds is the lift, or
drop, net. This net is usually
square in design, and it forms a
pocket when lifted directly up-
wards. Sometimes the netting is
supported by a rigid framework
which prevents collapse when low-
ering or lifting the net. Guy ropes
are attached to each corner to en-
able the operator to lift the net up-
ward on an even keel. On occasion.

instead of a rigid framework sup-
port, the netting is suspended from
flexible steel bands running diago-
nally across the net. "When the net
is lowered, the bands tend to flatten
out, and when lifted they bend in-
ward, creating a pocket (fig. 19).

Whether the drop net is small (3
feet square) or large (8 to 10 feet
square), the principle of operation
is the same. The net is lowered to
the desired de})th by hand in the
case of the small net, and by rope
from a tripod and pulley or on the
end of a pole in the large net.
Bread and cracker crumbs or oat-
meal are wetted and thrown into the
water inmiediately above the net to
attract the fish. T^sually, as soon
as the bait has dropped to a depth
ecpial to or nearly equal to that of
the set, the net can be lifted. When
the small net is used, the fish can be

34

HARVESTING FISH

Figure 18. — A wire trap built Into the Inlet of an artificial pond. When the trap is
not in use the ends are left open, as in the photograph. ( Photograph courtesy of
the Minnesota Department of Conservation. )

Figure 19. — A drop net used to remove fish from the poiul. Feeding is done on the
submerged net and from 2,000 to 3,000 minnows are raised at a time. (Photograph
courtesy of the Ohio Department of Conservation and Natural Resources.)

35

OPERATING THE HATCHERY

lifted in the net from the water and
poured into tlie holding cans.
Where larger nets are employed, the
"lift" should not clear the water,
but rise to a point where sufficient
water will be present for ample
movement of the captured fish. The
fish in the net can then be trans-
ferred to the holding cans with a
long-handled dip net.

Drop nets are operated success-
fully in quiet waters on certain
species, such as the golden shiner,
fathead minnoM', and creek chub.
Minnows can be collected efficiently
with little or no injury by this
method under the guidance of a
good operator. There are many ad-
vantages in using a drop net, where
practicable, instead of a seine. In
capture, the fish are not rolled,
crowded, or crushed ; the bed of the
pond is not broken, nor is the bot-
tom debris roiled to any extent.
Furthermore, minnows under sal-
able size can be returned to the
Avaters, uninjured.

In clear waters, the drop net w ill
work more efficiently for certain
species if the netting, ropes, and
frame support are dyed a neutral
color that harmonizes with the sur-
rounding water. In highly turbid

waters, dyeing would probably be of
no material value. Where fragile
minnows are being collected with a
drop net, the netting material
should be a soft fabric, such as
cheesecloth. When this material is
used, some minnows which scale eas-
ily, such as the golden shiner, can
be harvested successfully during the
hottest weather.

Dip nets. — The so-called dip net
is frequently used in taking shiners
in the Great Lakes. This net is usu-
ally of conical design, 1 to 2 feet in
diameter at the opening, and 2 to
?) feet deep. The rigid hoop that
forms the opening is fastened to a
handle. The mesh size of the net-
ting material used in construction
varies, depending on the size of the
minnows to be collected (fig. 20).

Scap nets. — A scap, or hand, net
is very useful in the handling,
sorting, and transfer of fish. Gen-
erally, the scap net is small, from
() inches to 1 foot across, if square,
and not more than 8 to 10 inches in
diameter, if round. The netting
material is supported by a rigid
framework attached to a wooden
handle. These nets usually have
shallow pockets. The netting ma-
terial is of small mesh and soft in

FiGUKK 20.— The dip net is used to handle bait fish in quantity.

36

ESTIMATING PRODUCTION

Figure 21. — The scap net has many uses about the hatchery.

texture so as to prevent injury to
the fish being handled (fig. 21).

Care of collecting gear

Nets should be carefully inspected
for holes, repaired when holes ap-
pear, and thoroughly dried after
each use. Nets should be stored
in a cool, dry place with a good
circulation of air. If they are fre-
quently used in waters rich in or-
ganic matter, it is well to have the
nets treated occasionally with a pre-
servative, such as tannin or copper
oleate. It is not desirable to use
tar as a preservative for minnow
nets because this substance has a
tendency to harden the fibers, and
tlius introduces conditions which
may be injurious to the fish being
handled. Nylon nets do not require
a preservative.

Small hand nets, such as dip nets
and scap nets, used daily in and
about a bait dealer's establishment,
when not in use, should be kept in
a sterilization bath consisting of a
weak chlorine solution. In this
way, disease organisms will not be
carried from one tank to another by
the nets. One formula used in
Michigan hatcheries consists of 26
fluid ounces of cleanser (3-percent
available chlorine) to 30 gallons of
water. As chlorinated solutions de-
teriorate rapidly in the presence of

organic materials or when exposed
to air, the bath must be strengthened
about once a week by adding 13
ounces of cleanser. Once a month
the entire solution should be dis-
carded and a new bath prepared.
A word of caution : chlorine is toxic
to fish, and discretion should be
used when disposing of old steril-
izing solutions.

ESTIMATING PRODUCTION

As soon as a tankload of fish has
been seined and transferred to the
live box, the fish should be weighed
(fig. 22), and carried in a pail of
water to the tank. The usual pro-
cedure is to hang the scale from a
tripod set in several feet of water.
A half -bushel metal basket is partly
filled with clean water. Ten pounds
of fish are weighed and carried to
the truck. By weighing 10 pounds
of fish at a time it is easy to keep
account of the fish taken, or the
production of a pond. Fish han-
dled in these amounts will not be
too crowded or easily injured. If
the operator is interested in know-
ing the number collected, he can
weigh and count the fish in 1 pound.

Another method of measuring
minnows that is not destructive of
the fish is the wet gallon measure.
A 5-gallon pail is marked off from
the li/^-gallon level to the top in

37

OPERATING THE HATCHERY

Figure 22.— Production should be determined by weijrhing rather than by volume.
(I'hotograiih courtesy of the Minnesota Department of Conservation.)

V2-Sallon units. When the fish
are to be measured, the pail is filled
with water to the n/a-gallon level
and minnows from a dip net are

38

added until the level reaches the 2-
gallon mark for half a gallon of
Hsh and to the 2i/^-gallon mark for
a full gallon. One gallon of min-

GRADING FISH

nows is counted when a large num-
ber of minnows are to be sold by
the dozen.

GRADING FISH

The most practical method of
sorting, or grading, fish — with the
least amount of damage to the fish
involved — is by using a mechanical
grader. Similar to those used in
trout culture, the bait-fish grader
consists of a wooden box having a
bottom of tubular grating (fig. 23).
The tubes, of lightweight metal of
about a i4"i'^ch diameter, extend

across the bottom of the grader,
producing a sievelike structure.
By regulating the spacing between
the tubes, fish of a desired size can
be retained in the box or permitted
to pass through. If the fish are to
be graded in several sizes, several
grading boxes will be necessary, one
for each size group desired.

Periodic sorting of the fish
throughout the growing season will
reduce the number of small fish that
have to be held through the winter,
and will result in greater produc-
tion of fish of a desirable bait size.

Figure 23. — Two sizes of slat sorting boxes used in grading minnows,
courtesy of the Minnesota Department of Conservation.)

( Photograph

39

OPERATING THE HATCHERY

TRANSPORTING AND HOLDING
BAIT FISH

Aeration and temperature control
are important factors in the success-
ful operation of both carrying and
holding tanks. A series of experi-
ments was run in Minnesota to de-
termine the effect of these factors
on the mortality of fish. It was
shown that fathead minnows ex-
posed over a period of hours to non-
aerated Avaters die with increasing
rapidity at the higher temperatures.
The most rapid loss occurs at tem-
peratures above 65° F. Fathead
minnows can be kept in well-aer-
ated water for several hours at rela-
tively high temperatures without
loss, and greater numbers of min-
nows can be carried at all tempera-
tures in aerated water than in non-
aerated water.

These experiments showed that
safe operation of minnow tanks re-
quires close adherence to the follow-
ing limits :

1. When tanks are aerated by circu-
lating water, a continuous flow of not
less than 1 gallon per minute for each
25 gallons of water in the tank should be
maintained. The water should reach
the tank from pressure jets placed so
the water is sprayed toward the op-
posite side of the tank. Each tank
should have a minimum of two pressure
Jets and at least one jet for every 25
gallons of water in the tank.

2. When oxygen or other forms of
aeration are used, the equipment should
be operated so as to maintain a mini-
mum of 3 p. p. m. of dissolved oxygen.
When oxygen is used for aeration, it
should be dispensed into the water
through carborundum tips or a per-
forated oxygen-release tube.

3. Water in nonaerated tanks should
be kept at 65° F. or lower.

A popular practice when han-
dling minnows is to fill the truck
tank at the bait store with cold
water (often around 50° F.).
While this water is being hauled
to the pond, it does not have time
to warm up very much. The min-
nows are seined from a warm-
water pond and placed in the cold
water of the tank with only a few
minutes of tempering. The shock
is not great enough to kill the fish
at once, but within a few hours a
large percentage will be dead.
Those that survive this period
usually develop fungus and die
within a few days. A minnow
should not be subjected to more
than a 10° F. change. A pocket
thermometer should be used to de-
termine temperature differences.

Likewise, bait fish that are to
be used locally should not be held
in very cold water unless the fish-
erman travels far enough for the
water to warm up. Minnows that
are taken from a cold minnow pail
and put into warm lake water will
turn belly up in a few minutes.

Transporting minnows

The hauling of minnows over
long distances during very hot
weather presents a difficult prob-
lem. Success depends on close ob-
servance of the following impor-
tant requirements:

1. Harden the fish before they are
transported. Conditions such as crowd-
ing, excessive handling, and changing
water temperatures, encountered when
transporting minnows for long distances,

40

TRANSPORTING FISH

often prove fatal to many of the flsh. As
a n)eans of reducing this loss, a 24-hour
"hardening" process is employed. The
fish to be transported are collected and
placed in a tank where the water tem-
perature can gradually be reduced until
it is between 50° and 60° F. The fish
are left in this bath for about 24 hours
for conditioning. At the end of this pe-
riod, they are transferred to transport-
ing tanks that contain water of the same
temperature and are ready for moving.
People who use this technique claim that
the fish will not only stand the trip bet-
ter but will tolerate more handling and
crowding than before hardening.

2. To prevent injury to the fish, the
wooden sides of the tank should be
smooth. Several types of tanks have
proved satisfactory. One popular type
is a single-compartment tank, 4 feet
square and 3 feet deep, aerated with oxy-
gen dispersed through a perforated re-
lease tube. This tank will carry 125
pounds of minnows for 300 or 400 miles
with little or no loss. Another success-

ful tank is 6 feet long, 3 feet wide, and
iy<i, feet deep. This tank is divided into
two compartments, each of which will
hold 100 pounds of minnows. It has the
advantage of permitting the dealer to sort
his fish either by species or by size
(fig. 24).

3. Carrying tanks must be well aerated
either by injecting oxygen into the water
or by pumping the water through pres-
sure jets. Under full load, any system
used should maintain a minimum of 3
p. p. m. of dissolved oxygen for the dura-
tion of the trip.

All carrying tanks used on long hauls
should have two aerating devices that
can be operated independently of each
other, in case one breaks down. An oxy-
gen tank can be substituted for one pump
in most cases.

Aeration is sometimes obtained from
wind scoops and water pumps driven by
the truck motor. Both of these methods
depend for their success on the ability of
the truck to maintain motion. When the
truck breaks down the fish are out of oxy-

FiGUBE 24. — An inexpensive fish-distribution tank truck. (Photograph courtesy of
the Minnesota Department of Conservation.)

41

OPERATING THE HATCHERY

gen in a short time. Such devices should
only be used as auxiliary equipment or as
primary oxygen sources when supple-
mented by other sources that are inde-
pendent of the truck motor.

4. When the trip is unusually long and
the weather extremely hot. the tempera-
ture should be maintained between 65°
and 70° F. by periodic icing. When pos-
sible, long hauls should be made on cool
days. Tanks that are constantly used
for long hauls .should be insulated with
a 4-ii;ch layer of cork.

Occasionally the dealer will find it nec-
essary to temper minnows as they are
being transported from the lake or stream
where they were seined. For this pur-
pose the truck must be equipped with a
small box of ice. The minnow tank is
filled with lake or stream water and the
aeration pump is adjusted so the aerated
water passes over the ice before it re-
turns to the tank. Periodically the op-
erator will have to stop the truck and
take the temperature of the water in the
tank. When the water is of suitable tem-
perature, the water line to the ice box
should be shut off. If the water in the
tank is cooled too much or too rapidly,
the minnows will develop fatal "frost
bites." The water line to the ice box
must be equipped with a valve so the rate
of cooling can be adjusted.

Some dealers cool the tank water by
using the live box as an ice tray. After
the truck tank is loaded with water and
minnows the live box full of ice is placed
over the top of the tank. The tank water
is cooled as the ice melts and drips into
the tank. The cooling rate cannot be
controlled by this method and more fish
suffer from "frost bite" from it than from
the ice box.

5. Salt is a tonic for fish and can be
used to help them over the rigors of trans-
portation. A salt bath should be given
after the trip. When the aeration equip-
ment consists of a pump and water jets,
salt should not be u.sed in the tank be-
cau.se sodium chloride rusts' the ecjuip-
inent.
0. Truck tanks should never be over-

loaded, especially during hot weather or
on long trips. A load of 9 gallons of min-
nows per 100 gallons of water, or 5.6
pounds of minnows per cubic foot of
water, has been found safe under severe
conditions.

Operating the holding tank

The bait dealer encounters his
greatest loss from handling and
holding minnows in the holding
tank. Though much of the loss is
attributed to fungus disease, the
largest part is the direct result of
rough handling and careless opera-
tion. There is no magic formula
for preventing minnow losses. Dis-
ease-control treatments will not pre-
vent losses due to careless handling,
but following the suggestions given
here will help to keep losses in bait
fishes to a minimum.

1. Minnows should be handled carefully
during seining operations. Dealers who
buy their minnows should refuse to ac-
cept fish that have been handled roughly.

2. The minnows should be carefully
tempered when they are transferred to
the truck tank and again when put in
the holding tank (see p. 41 for "harden-
ing" process).

3. The minnows should not be crowded.

4. Holding tanks should be constructed
of wood or smooth concrete, and painted
heavily with asphaltum paint. Smooth
sides in the tank help prevent disease
and injury to the fish. The tank should
be deep enough so that the fish are not
injured by the jets of water used for aera-
tion. The bottom should slope slightly
toward the outlet to facilitate cleaning
and draining.

5. Each tank should be supplied with
plenty of filtered water — spring water is
filtered — and each tank should drain di-
rectly to the .sewer without passing
through other tanks. The water should
enter the tank through pressure jets

42

HOLDING FISH

placed well above the surface of the
water. One overflow outlet should be at
or near the bottom to remove stagnant
water and waste material.

6. Well water containing more 'than
1 p.p.m. of iron will cause heavy minnow
mortality. Iron can be removed from
the water with the right kind of filter.
Some water-softening filters will remove
iron if the water is aerated before it
is filtered.

Copper well points and copper water
pipes often give off enough copper to
kill minnows in holding tanks. This is
especially true in soft water or where
the pH is high. In such cases, the of-
fending pipes must be replaced with iron
pipes.

7. Each tank should be small enough
that the complete contents can be sold
in a few days. No more fish should be
added until these are sold, and the tank
should never be overloaded. The trans-
fer of fish from one tank to another will
greatly aid the spread of disease.

8. When the fish from one tank have
been sold, the tank should be drained
and carefully cleaned. The sides and
bottom .should be thoroughly scrubbed
with a 1 : 10,000 solution of sodium hypo-
chlorite. This solution is mixed by add-
ing 1 quart of sodium hypochlorite or 3
to 5 quarts of any commercial bleach to
250 gallons of water. The tank should
be thoroughly sterilized at least once
a week. After an ample rinse the tank
can be filled with water and stocked with
fish.

9. All dead fish in the tanks should be
removed immediately and destroyed.

10. There may be considerable loss
from the common practice of selling
minnows wholesale by the gallon. This
procedure necessitates the measuring of
minnows in a nearly dry state. Such
measuring cannot be done without injury
to the fish.

11. Very large dip nets should not be
used for minnows. Lifting a half bushel
of minnows in a dip net is likely to injure
those on the bottom. Overloading

smaller nets will also produce injury and
consequent loss of fish.

12. Feed minnows that are held for
more than a few days. A series of feed-
ing experiments conducted by the Wis-
consin Fi.sh Management Division to de-
termine the effect of food on the loss
of minnows in holding tanks, showed that
brassy minnows could be held for 63 days
at 46° F. with very little loss of weight
when fed all the canned carp they could
clean up. Fish that received half as
much carp survived nearly as well and
showed only slightly more loss of weight.
Fish that received no food succumbed to
heavy infestations of fungus, but those
receiving food had very little fungus.

Minnows will eat a variety of foods,
but the most practical foods are those
that are easy to handle and ccmvenient
to store. The food should appeal to the
fish so that it is consumed fast enough
to prevent undue contamination of the
tank water. Oatmeal and cottonseed
meal are satisfactory foods. Meal worms,
ftour-weevil larvae, and similar worms
are very attractive to minnows and form
a substantial food ; but all must be raised
for the purpo.se, As this takes quite a
bit of time and space, most bait dealers
do not use these organisms. Dry dog
foods or commercial fish foods can be
used as a balanced diet that is easy to
handle and is reasonable in cost.

13. Early treatment of diseased fish is
important. Epidemics of fungus disease
will produce a large loss of fish in hold-
ing tanks. While careful seining, trans-
portation, and holding of the minnows
will greatly reduce the chances of an
epidemic starting, it may happen even
in the best-regidated establishments.

At the start of the epidemic all dead
fish should be removed and destroyed
at once. The remaining fish should be
dipped in malachite green 1 : 15,000 solu-
tion (Ys ounce in 15 gallons of water)
for 10 seconds. The tank must be
drained and sterilized with sodium hypo-
chlorite 1 : 10,000 solution. All tools and
dippers must be sterilized in the same

43

OPERATING THE HATCHERY

solution and must be resterilized daily
until the epidemic is over.

Addition of some disinfectants and
drugs to water in tanks holding fish is
recommended by numerous investigators
for the control of various fish infections.
Since a number of these methods are of
recent origin they have not been tried
vmder various conditions and with dif-
ferent species of fish. Therefore, it is
po.ssible that drugs listed in the section
on diseases (p. 57) may be found toxic
to .some species of minnows or aquarium
fishes and entirely harmless to other.
All of these drugs are used in highly
diluted forms and the fish should be able
to remain in such medicated water for
2 to 3 days, or even longer, without any
apparent injury. If treatment should
last more than a week, water in the tanks
should be changed frequently, prefer-
ably every 3 to 6 days. After each change
of water, the required quantity of fresh
drug should be added. Treatments
should not be carried on for more than 2
weeks at a time to reduce the possibility
of devlopment of drug-resistant strains
(varieties) of the disease-producing
organisms.

Since some of these chemicals may be
found to be toxic to some fishes under
all conditions or under special condi-
tions like high temperature of water or
oxygen deficiency, all treatments should
be made with great caution and tried
first with a small number of fish. The
medicated water should be replaced with
fresh water whenever fish show any signs
of distress.

Infected minnows should not be pur-
chased or seined, as the danger from
loss and spread of disease to healthy fish
is too great. During times of scarcity
when only infected minnows are avail-
able, the fish should be dippe<l for 10
seconds in a 1 : ir),(K)0 solution of mala-
chite green before being placed in the
holding or tempering tanks. The mala-
chite green should be discarded after 100
pounds of minnows have been treated or
at the end of the day.

14. Minnows that have not spawned
.should be placed in warm-water ponds
until they spawn. Then they can be put
in cold-water tanks or iK)nd.s and held
for long periods without heavy losses.

When men of the Wisconsin Fish Man-
agement Division were conducting feed-
ing experiments with brassy minnows,
they noticed an increased mortality dur-
ing May and June. Post-mortem exami-
nations revealed that the majority were
gravid, egg-bound females. That they
were ready to lay eggs but could not be-
cause of the cold water was interpreted
as the cause of their deaths. This may
account for part of the heavy loss of min-
nows in cold-water holding tanks during
the warm summer months.

Holding minnows in ponds

In some States, lioldin^ ponds are
a mucli debated subject. The bait
dealers insist that they must have
holding ponds to sta}^ in business,
and the conservationists maintain
that holding ponds are one of the
chief causes of minnow losses. The
opponents to holding ponds point
out that most ponds are used to hold
lake shiners from early spring
when they are abundant until sum-
mer when tliey are needed for bait,
tliat the shiners do not thrive in
holding ponds because most of the
ponds are too cold, and the fish be-
come egg bound, and furthermore,
that fish held in ponds are not able
to spawn that year and both the
adults and tlieii- reproduction are
lost from the lake. The problem is
usually solved on a compromise
basis that limits the number and
size of the ponds that each dealer
can use.

On the other hand, all parties
agree that holding ponds are in-

44

WEED CONTROL

dispensable to the hatchery opera-
tor who wishes to produce a year-
round bait supply from his produc-
tion ponds. Minnows for the early
fishing season must be over-win-
tered in ponds that will maintain an
ample supply of oxygen through the
longest winter.

The most satisfactory ponds are
those supplied with an ample
amount of oxygen-bearing, running
water from rivers, creeks, springs,
or flowing wells. There are advan-
tages and disadvantages to all of
these sources. Water from unpol-
luted rivers and creeks is usually
high in oxygen and contains some
natural minnow foods, but it may
not always be of the right tem-
perature. Water from springs and
flowing wells is usually cool and of
uniform temperature, but it is often
low in oxygen and is always low
in natural minnow foods. Spring-
w^ater must usually be run over a
riffle before it enters the pond. This
means that fish held in ponds sup-
plied with stream water will not
need as much artificial food, but
they must be moved to growing
ponds before the water warms up
in the summer. Minnows held in
spring-water ponds can be left in
the j)onds all year round, but they
will require large amounts of artifi-
cial food.

Holding ponds should be small
enough and shallow enough so that
the fish can be readily removed
whenever they are needed. An acre
pond that is 4 or 5 feet deep is very
practical, and a number of small
ponds is preferable to one large

pond because different species and
different sizes of minnows can be
held separately in the small ponds.
This usually reduces losses and
minimizes the sorting operations in
the spring.

In areas where holding-pond con-
struction is not practical, minnows
can be overwintered in production
ponds, if the ice is kept free of
snow all winter. There are several
ways to remove snow from the
ponds, but the use of soot spread
thinly over the snow seems the most
practical. The soot absorbs enough
heat from the sun to melt 6 to 9
inches of snow and ice. In areas
of light snow, plowing may be prac-
tical, but in regions of 3- to 6-
foot snowfalls plowing is very ex-
pensive. Some operators use a
centrifugal pump to spray water
over the snow ; the resulting slushy
condition usually freezes to clear
ice that transmits enough light to
keep the plants producing oxygen.

WEED CONTROL IN
PONDS

With good pond management,
weed control is generally not a prob-
lem. Ponds that are farmed inten-
sively are heavily fertilized, either
directly by the use of fertilizers or
indirectly by food that is not picked
up by the fish and by the heavy
concentration of excretory products
that results from large populations.
Under these conditions, submerged
vegetation will be controlled by the
waterbloom produced, and emer-
gent vegetation such as cattails or

367913 0—56-

45

OPERATING THE HATCHERY

pickerel weed, will invade the pond
rather slowly, and can be controlled
by hand or by the use of chemicals.

Water quality and temperature
are controllin*; factors in the effec-
tiveness of treatments to kill vege-
tation and in the toxicity of the
chemicals to fish. Each hatchery
presents a different situation with
a new set of conditions, so that it
is necessary at first to experiment
on a small scale with control meas-
ures, and modify them to fit the
local situation. We can only give
general recommendations, which
must be adjusted to meet the specific
conditions in an area.

Many things can be done in pond
management that will make the con-
trol of pond and emergent vegeta-
tion simpler. Among these are the
following :

1. A bloom heavy enough to shade out
the rooted plants should be maintained
throughout the season. A bloom that
hides the pond bottom at a depth of 1
foot is heavy enough for this purpose.
The pond will have to be watched closely,
as there is danger that the bloom may
become heavy enough to cause an oxygen
depletion during warm nights. This
method has the advantage of producing
fish food while controlling the weeds.

2. Deep shorelines (at least 18 to 24
Inches) at the edge of the bank combined

with a waterbloom will discourage
emergent vegetation, as bulrush, arrow-
head, and cattails.

.'{. Pond banks that can be mowed,
with a good cover of hardy grasses, wall
discourage invader plants from the shore,
such as wildmillet and parrotfeather.

4. If a bloom is kept on the pond, the
repeated cutting of emergents below the
surface is an effective means of control-
ling undesirable vegetation in the pond.
In shallow ponds a scythe will be the
most satisfactory tool, but in deep ponds
one of the mechanical weed cutters is
necessary. When iwssihle, the vegeta-
tion should be raked up on the banks to
prevent an oxygen depletion when it
decomposes.

CHEMICAL AGENTS

Subject to local conditions, the
following table lists chemical agents
which may be used to control the
various weed plants. Plants should
be treated while they are young and
actively growing. Do not wait un-
til they become a nuisance, because
controls then may be only partly
effective and a great deal of time
and money will be lost. Always
kill the vegetation before the seed
forms. The data in the three fol-
lowing tables are taken from the
Fish-cultural Manual, Region 2,
o^lbuquerque, N. Mex., U. S. Fish
and Wildlife Service.

46

WEED CONTROL

Plant

Floating plants:

Duckweed

Filamentous algae. .
Water hyacinth

Emergent plants:

Alligatorweed

Burreed

Cattail

Cow lily (yellow

lily).

Duckpotato

Giant cutgrass

Grass (most kinds).

pond

Johnson grass .

Lotus

Maidencane...

Parrot feat her

Reed's canary-grass_

Smartweed

Softstem bulrush

Squarestem bulrush

Water chestnut

Watercress

Weakrush

White waterlily

Submerged plants:

Bladderwort

Chara (muskgrass)

Coontail

Curly leaf pond weed

Fineleaf pond weed

Leafy pond weed

Naiads

Parrotfeather

Water crowfoot

Water milfoil

Water purslane

Water stargrass

Waterweed (Anacharis)_

Woody plants: All species.

Chemical agent

2,4-D

Copper sulfate -
2.4-D

.do_

.do-,
.do'.
.do__

-do-
-do.

Sodium TCA.

2,4-D. _
do.

Sodium TCA.

2,4-D

Sodium TCA.

2,4-D_.

do.

do.

Sodium arsenite.

2,4-D..
do.

-do.

Sodium arsenite -
Copper sulfate . _
Sodium arsenite.

do

do

do

.do.

do.

_do.

do.

do.

do.

do-

2,4,5-T_

Application

1 % solution in oil.^

3 lbs. of crystals per 1,000 sq. ft.

0.5% solution in oil.^

1 % solution.

Do.
0.5% solution in oil. 2
1 % solution in oil.^

1% solution.

1 % solution in oil.^

7 oz. per 5 gal. of water (1%

solution).
1 % solution in oil. 2
0.5% solution in oil.^
1 lb. dry powder per gal. of

water.*
0.5% solution in oil.^
1 lb. dry powder per gal. of

water.*
1 % solution.
1 % solution in oil. 2
0.5% solution in oil.^
1 lb. powdered sodium arsenite

plus 1 lb. sodium chlorate in

1 gal. of water to 150 sq. ft.

1 % solution.

Do.
2% solution in oil.^

2.5 p. p. m.5

3 lb. of cry.stals per 1,000 sq. ft.

2 p. p. m.5
2.5 p. p. m.s

2 p. p. m.8

D0.5
2.5 p. p. m.5

3 to 4 p. p. m.5
3 p. p. m.5

3 to 4 p. p. m.5

Do.*
2.5 p. p. m.5
2 to 4 p. p. m.5

2.3 qt. of 44% esters per 100 gal.
of water.'

1 In water solution, unless otherwise specified.

2 Refer to dilution table, p. 48.

' 3 oz. Esteron 44 in 1 gal. of kerosene or fuel oil, plus a detergent, is very effective
on cattails and rushes. Highly volatile and should not be used if damage to adajacent
croplands probable, in which case use instead Estericide D-4.

* Effective if sprayed twice when pond is dry.

* Liquid form is most convenient; for example, 5}i pt. of Atlas "A" (contains
4 lb. /gal. AS2O3, the active ingredient) per acre-foot equals 1 p. p. m. Do not treat
more than one-third of pond area at a time because of danger of oxygen depletion.
See table, p. 48, for concentrations.

8 Spray during active growing season and thoroughly wet the plants. Include a
detergent in the solution.

47

OPERATING THE HATCHERY

The amounts of commercial solu-
tions of 2,4-D that are required to

spray an acre of water are shown
in the following dilution table:

Acid content of 2,4-D
(percent)

Amount of 2,4-D needed for 100 gal. of spray
with a strength of —

10,000 p. p. m.
(1 percent solution)

5,000 p. p. m.

(0.5 percent

solution)

90

81b. 12 oz

9 lb. 6 oz

10 1b

4 lb. 6 oz.

85

4 lb. 11 oz.

80

5 lb.

70

111b. 14 oz

13 1b. 12 oz

2.5 gal

5 gal _. . .

5 lb. 15 oz.

60 -

6 lb. 14 oz.

40 (liquid) _ .__

5 qt.

20 (liquid) . _.-_--

2.5 gal.

10 (liquid)

10 gal

5 gal.

Under average conditions, 2.5
p. p. m. sodium arsenite will provide
adequate control of rooted vegeta-
tion as well as pond scum. In some
waters of high mineral content, par-
ticularly in the Southwest, 8 p. p. m.
or more may be required. This can
only be determined by trial.

The amount of liquid sodium ar-
senite (containing 4 pounds of a,r-
senious oxide per gallon) that
should be used in a section of pond
where the average depth and surface
area in square feet are known and
where a concentration of 8 p. p. m.
is desired is as follows:

Average depth

Amount of sodium arsenite needed to spray —

(feet)

1,000 sq. ft.

1,500 sq. ft.

2,.500 sq. ft.

3,500 .sq. ft .

0.1

50 cc

150 cc

250 cc

375 cc

Ipt

1.5 pt

1 qt

2.5 pt

3.5 pt

2 qt

4.5 pt

5 pt

75 cc -_. ._

125 cc

375 cc

1.5 pt

1 qt

2.5 pt

3.75 pt

2.5 qt

6.25 pt

8.75 pt

5 qt

175 cc.

0.25 -. .

225 cc

375 cc

Ipt

1.5 pt

2.25 pt

3 pt

525 cc

0.5

1 qt.
3 pt.
3.5 pt.
5.25 pt.
3.5 qt.
8.75 pt.

6 qt.

7 qt.

0.75

1

1.5

2

2.5

3.5

1 qt

5.25 pt

3 qt

4

4.5

6.75 pt

7.5 pt

Igal

4.5 qt

11.25 pt

12.5 pt

7 qt

2 gal.

9 qt.

10 qt.
10.5 qt.

5

5.5

5.5 pt

3 qt

6

7.5 qt

48

WEED CONTROL

For 1 acre-foot (an acre of water
1 foot deep) use 5.3 gallons of
sodium arsenite spray ; for i/^ acre-
foot, or for 4 p. p. m. on 1 acre-foot,
use 2.65 gallons.

If you are in doubt concerning
the type of vegetation in your pond,
you should send samples of the
questionable species with either the
blossoms or fruit to the nearest
State University for identification.
Submerged vegetation should be
thoroughly dried before mailing it.
Preparation of the specimen is best
accomplished by spreading the
plant flat on a piece of paper or be-
tween the folds of a newspaper, and
placing a weight on it until dried.
Attach a label to each sample giv-
ing such information as you can
about the location and depth of
water where the plant was found.

APPLYING CHEMICAL AGENTS

The best way to apply a weed
killer is in liquid form. It is neces-
sary that sprays be applied directly
on the plants (in controlling emer-
gent vegetation), or to areas where
the plants cover the bottom of the
pond (in submerged vegetation).

Sodium arsenite

Sodium arsenite is heavy and
sinks rapidly to the bottom. Con-
sequently, the areas to be treated
can be restricted by spraying only
those places where it is intended to
kill submerged vegetation. Some
time will elapse before the effect of
the chemical can be noticed. Since
the vegetation that is killed will be-

gin to decay and remove oxygen
from the water, it is advisable to
treat not more than one-third of
the pond at one time. The re-
mainder can be sprayed a few days
later. This gives the fish an op-
portunity to move into waters
where oxygen is available.

To hasten the effect of sodium
arsenite, it is helpful to fertilize the
areas where the weeds are begin-
ning to die. This will produce a
waterbloom and oftentimes will re-
sult in a complete kill of all vege-
tation in the pond, thus eliminat-
ing the need for the use of chemi-
cals on the untreated areas.

Sodium arsenite is very poison-
ous, and care should be taken when
applying it that the spray is not
inhaled and does not come in con-
tact with the skin. Livestock
should be kept away from sprayed
ponds for at least 2 days. Con-
tainers in which the chemical has
been mixed should be thoroughly
cleaned and removed from places
where livestock may have access to
them. The water itself is not poi-
sonous, since the amount of chemi-
cal used is not sufficient to provide
a lethal dosage.

Copper sulfate

Copper sulfate should be ob-
tained in small crystals so that it
can be spread evenly over the area
to be treated. As in the case of
sodium arsenite, only part of the
pond should be treated at one time,
and copper-sulfate crystals should
never be in excess of 0.5 p. p. m. for
the pond as a whole. Also, fertili-

49

OPERATING THE HATCHERY

zation of the treated area will as-
sist in producing a waterbloom, par-
ticularly if the vegetation is heavy.

2,4-D

In the use of 2,4-D, it is essential
that a uniform application be made
on the treated area and that all
plants be thoroughly wet. Under
these conditions, usually about an
80- to 90-percent kill results, and a
second application must be made
wherever new shoots appear. This
may be followed by an occasional
shoot appearing that can be pulled
by hand.

SPRAYING EQUIPMENT

Many sprayers are on the market
that can be used to spread these
chemicals. If considerable use is
to be made of such equipment, it
probably would be ad\nsable to
have a sprayer that can be mounted
in the back of a truck. There are
many pieces of equipment on the
market designed for specific jobs.
Large dealers handling farm equip-
ment or garden supplies can recom-
mend the proper piece of equipment
for your specific needs.

CONTROLLING DISEASES
AND PARASITES

When raised in ponds, minnows
can be expected to suffer from many
of tlie diseases of hatchery fishes.
For this reason, it seems wise to
mention some of these diseases and
parasites, and to outline briefly a
program for their prevention and

cure. Moreover, diseased and ail-
ing fish are often collected by un-
suspecting dealers, or the fish may
become fungused from improper
handling in the nets or tanks.

The best method of disease con-
trol in a hatchery is prevention.
Fish that are handled properly and
that are adequately "tempered" be-
fore handling will usually be free
from disease.

Bait fishes are infested by several
kinds of parasites, and the follow-
ing numbers of species have been re-
ported from them :

Number of
parasites

White sucker 20

Golden shiner 14

Bluntnose minnow 9

Western mud minnow 4

Common shiner 3

Fathead minnow 2

Silvery minnow 2

Most of these parasites will not
cause loss, and only a few are char-
acteristic enough for the hatchery-
man to recognize. Most likely to
cause considerable loss in bait fishes
are fungus diseases, fin or tail rot,
black grub, and certain other dis-
eases that are discussed in succeed-
ing pages.

WHEN TO TREAT

In any method of treatment, time
is of vital importance. Disease rap-
idly lowers the vitality of small fish,
and although today they can with-
stand the rigors of treatment, to-
morrow may find them too weak.
The fish culturist must maintain
strict watch on his stock. Early
warning of the presence of many

50

DISEASE CONTROL

external parasites is evidenced in
the fish refusing to eat, scratching
themselves, or assuming a character-
istic bluish-gray sheen. Fungus is
an excellent indicator of trouble, but
it usually does not appear until after
the telltale rise in the daily losses —
which is the surest proof that
trouble is present.

Immediately upon any suspicion
of trouble and always in the event
of increasing losses, the fish should
be carefully examined for gross
lesions, and all possible extraordi-
nary factors, such as bad food, silt,
and sudden fluctuations in water
temperature, should be checked. If
none of these is involved, the fish
should be examined for parasites
and microscopic lesions. There are
many diseases of fishes w^hich are
diiRcult to diagnose or treat, or both.

When in doubt as to the cause of
losses, the fish culturist should seek
the advice of a State fishery biolo-
gist. Whenever it is necessary to
send the diseased fish to a diagnos-
tic laboratory, the specimens se-
lected should be fish with the most
typical symptoms or signs of the
disease, but still living. It is very
difficult and often impossible to
diagnose a disease from a dead fish.
If living fish cannot be brought to
the laboratory, live fish with typical
symptoms should be placed in a jar
containing 1 part of commercial
formalin diluted with 3 to 4 parts
of w^ater. A letter should accom-
pany the specimen, giving as de-
tailed information as possible re-
garding the progress of the disease,
percentage and rate of losses, and a

detailed description of the condi-
tions existing in the pond or tank,
such as turbidity, presence of vege-
tation, waterbloom, water tempera-
ture, and any treatment of the pond
or fishes. The more accurate the de-
scription of the symptoms and con-
ditions that is given the more likely
it is that the biologist will be able to
determine the cause of trouble and
recommend treatment.

METHODS OF TREATMENT

Regardless of the concentration
of the disinfectant used, the tech-
nique of application influences the
success of any treatment to no small
degree. It might, therefore, be ad-
vantageous to briefly outline the
various methods of treatment in
common use and the recommended
techniques.

Salting

Salting is good trough treatment,
but it will not cure everything. In
troughs, it is extremely simple to
apply, is reasonably effective
against external protozoan para-
sites, is an excellent tonic for the
fish, and its application demands
the least accuracy of any known
form of treatment.

There are many w ays to treat fish
by salting, and some methods are
better than others. In the method
recommended here, fish are treated
v/ith a known concentration of com-
mon salt. Salt should be dissolved
in water in a quantity to give a 3-
percent concentration when added
to the water in which the fish will

51

OPERATING THE HATCHERY

be treated. This can be done by de-
termining the volume of water con-
tained in a trough or tank at an
arbitrarily predetermined depth,
say 2 inches (5 cm.)- By multiply-
ing the inside length of the trough
by the inside width and the product
of these two numbers by the prede-
termined depth, all expressed in
inches or centimeters, one can cal-
culate how much salt to use. A
3-percent concentration can be ob-
tained by using 1 ounce of salt to
each 60 cubic inches of water, 30
grams to the liter, 4 ounces to the
gallon, or 30 ounces to the cubic foot
of water. To give fish a salting,
shut oflf the inflowing water, drain
the trought to the predetermined
depth, remove some of the water in
a bucket and add the required quan-
tity of salt, dissolve the salt, and
mix this strong solution with the
water in the trough.

Fingerling trout will withstand a
3-percent concentration for 6 to 10
minutes. Most minnows will prob-
ably stand this treatment for only 2
or 3 minutes. When several of the
weaker fish have turned over, the
inflow is resumed at the maximum
rate which the fish will withstand
and the drain is partially opened to
permit a rapid replacement of the
salt water. This method may be
applied to fish as often as desired
without apparent injury and, in-
deed, with a definitely tonic eflfect.
When repeated three times at 24-
hour intervals, salting is quite ef-
fective in curbing epidemics caused
by external protozoans, and it is
the only treatment which should

ever be applied in the absence of
definite knowledge regarding the
cause of any mortality. Salting,
however, becomes progressively
more expensive, less effective, and
more difficult to apply as the size
of the body of water to be treated
increases.

Flushing

Control of fish pathogens or para-
sites by flushing does not have wide
use, but in certain instances it is
quite effective. Flushing consists
in routinely adding a stock solution
of a disinfectant or drug of known
strength to the upper end of a
trough and allowing it to flow down
the trough and out. Most fre-
quently it is used with malachite
green to control fungus infection
of fish eggs during hatching. Pre-
liminary experiments also indicate
that such treatment with malachite
green may be of use in control of
the external infection of fish by
fungi belonging to the genus Sapro-
legnia. The most-frequently used
procedure is to make a stock solu-
tion containing 0.5 gram of pure
malachite green per liter of water
(2 grams to the gallon, 1 ounce to
14 gallons) and after the dye is
completely dissolved, 100 milliliters
(3.5 fluid ounces) of the solution
should be poured in at the head of
the trough and half of that amount
in the middle of the trough. Bur-
rows (1949) described a treatment
of eggs by a constant flow of mala-
chite-green solution.

Malachite green also can be
added in powdered form to a fish

52

DISEASE CONTROL

tank or concrete pond, and dis-
solved by mixing. In such cases
it should be added at a rate of 1
p. p. m. Water containing mala-
chite green should be gradually
replaced with fresh water. If the
flow of water is such that the con-
centration of the dye wnll be re-
duced in the pond by about 50
percent during the first hour, no
toxic effect on fish should be no-
ticeable. The use of malachite
green requires further investiga-
tion.

Dipping

The third basic method of con-
trolling diseases and parasites in
bait fishes, hand dipping, could be
the subject of several volumes.
Suffice it to say that it is a danger-
ous treatment, for the solutions
used are powerful and relatively
concentrated. Hence, the differ-
ence between an effective dose and
a killing one is exceedingly nar-
row in view of our present lack
of knowledge concerning this very
common method of treatment.
When applied with extreme care,
dipping undoubtedly may be of
great value in controlling infesta-
tions of external parasites and in-
fections caused by certain types of
bacterial diseases, such as fin rot
and the eastern type of gill dis-
ease. Certainly, hand dipping
should never be applied to any
large number of fish unless there
is valid reason to believe that
some external parasite is causing
the losses. In the absence of such
reason, a dip should be applied to

a small number of fish as an ex-
periment. If the percentage loss
in this experimental group does
not fall significantly below that of
the rest of the affected fish within
2 days after the experimental
treatment w as given, hand dipping
should not be used.

Hand dipping, in the opinion of
the authors, is best done in a dip-
ping box. This apparatus con-
sists of a solidly constructed, water-
tight, w^ooden box— in cross sec-
tion about 2 inches narrower than
the hatchery troughs, about half
again as deep, and approximately
o feet long. The height reached
by a known volume of water is
legibly marked on the box. In the
dipping box is slung an inner com-
partment, with four ears which
are sufficiently wide to rest on the
top of the dipping box, yet suffi-
ciently narrow to permit the com-
partment to slip into the hatchery
troughs. This inner compartment
has two wooden sides which round
vertically at the ends, and the bot-
tom is covered with a galvanized,
coarse wire mesh. If a dip bath
is used that contains copper sul-
fate or acetic acid, the galvanized
screen should be painted with as-
phalt, since even traces of dissolved
zinc may be toxic to the treated
fish. The galvanized mesh, in turn,
is covered on the inside with bob-
binet, that is caught to the wire
mesh at a sufficient number of
points to keep it from floating off.

The desired quantity of disinfect-
ant is w^eighed out and dissolved
in the dipping box which has pre-

53

OPERATING THE HATCHERY

viously been filled with water to
the calibration mark. The inner
compartment is then placed in the
trough which contains the fish to
be treated, and a convenient num-
ber of fish from the trough are
placed in it by means of a scap
net. The compartment is then re-
moved to the dipping box and the
fish immersed in the disinfectant.
After the required time for the dip
has elapsed, the inner compartment
is carefully lifted from the dip-
ping box and innnersed in the
trough to which the treated fish
are being transferred. By slowly
lifting the "upstream" end of the
inner compartment, the fish slip
out into the trough. The solution
in the dipping box should be aer-
ated constantly and renewed fre-
quently. Differences in water tem-
perature between the infected
trough, the dipping box, and the
treated trough should at no time
exceed 5° F.

For treatment by dipping as
used most frequently, the formula
for external parasites is glacial
acetic acid, 1 part dissolved in 500
parts of water; for gill disease, it
is 1 part of copper sulfate (blue
stone) in 2,000 parts water; and
for various external infections with
animal ])arasites and fungi, it is a
o-percent solution of salt. Fish
are usually dipped for 1 minute in
acetic acid and copper sulfate, and
in salt for several minutes until
the weakest fish begin to turn over.

Prolonged treatment

Prolonged treatments are based
on the theory that long exposure to

a dilute solution of disinfectant is
more effective and less toxic than
is the shorter, more-concentrated
hand dip. Furthermore, prolonged
treatment may be applied without
liandling the fish, a factor which is
not serious if the fish are carefully
treated from troughs, but may be-
come very serious when the fish are
in ponds or pools where a seine
must be used and a large number of
fish is involved.

Prolonged treatment originally
consisted of adding to the inflow-
ing water a sufficient amount of
dissolved disinfectant at a uniform
rate to maintain a constant concen-
tration of disinfectant over a defi-
nite period of time, usually 1 hour.
This method of treating the inflow-
ing water is subject to an inherent
inaccuracy due to the diluting influ-
ence of the residual water in the
pond at the time treatment is
started. Although not serious in
the case of troughs or small race-
ways which may be drained prac-
tically to dryness and which fill rap-
idly, the inaccuracy becomes pro-
gressively greater as the size of the
body of water to be treated is
increased.

For treatment of fish in larger
water areas, such as circular pools,
raceways, or ponds, the prolonged
treatments are identical in princi-
ple to salting, page 51. The volume
of water in the pool (capacity of
the pool) to be treated must be
known ; then the required quantity
of the disinfectant is weighed, or
measured by volume if it is a liquid,
and dissolved in a small quantity of

54

DISEASE CONTROL

water. This stock solution is mixed
thoroughly and quickly with the
water in the pond. To ensure an
even distribution of the disinfectant
and to aerate the water dtiring
treatment, the w\ater should be re-
circulated in a closed system from
the lower end of the pond to the
upper end b}' means of a centri-
fugal pump.

Prolonged treatments can be car-
ried out easier if fish are not fed
for 24 hours before treatment. This
reduces the fishes' metabolism rate
and oxygen requirement. Accord-
ing to Fish (1947), for safe treat-
ment, fish should not be too
crowded; there should be no more
than that 1 part of fish by weight
to 100 parts of water ( 1 pound of
fish per 12 gallons of water). If
such a ratio is maintained, the flow
of water or aeration can be cut off
for 1 hour.

Gammexajie has been described as
an effective treatment for infesta-
tion with ArguJus, a copepod. It
should be added at a rate of 1 part
to 10 million parts of water to the
pond or tank holding the infested
fish. In tanks, the medicated water
should be replaced with fresh water
after 2 to 3 days of treatment.
How effective ganxmexane is for the
treatment of infestations caused by
Lernea (another copepod) is not
known at this time.

The most-frequently used pro-
longed treatments are with formalin
and pyridylmercuric acetate, tech-
nical (P.M.A.). Formalin is added
to water at a rate of 1 part of
formalin (containing about 40 per-

cent formaldehyde) to 4,000 parts
of water by volume. Pyridylmer-
curic acetate (P.M. A.) is used at a
rate of 2 parts per million. Treat-
ment with formalin is effective
against many of the external para-
sites, like Gyrodactyhis^ DaHyJogy-
rus^ Chilodon., Costia^ Trichodina^
fin rot, and others. A 10-percent
stock solution of P.M.A. can be
easily prepared and kept on hand
when needed. P.M.A. is used
mainly for the treatment of gill
diseases, but some of the external
parasites listed here are also af-
fected by it. P.M.A. is toxic to
some fish, like rainbow trout. It
is not known how toxic it may be
to minnows and other bait fishes.

Antibiotics, such as chloram-
phenicol and terramycin, have been
found to be effective in the control
of ulcer disease and furunculosis in
trout and red-leg disease in frogs.
Since the bacterium PseudoDionas
{Aeromonas) hydrophila^ which
causes red-leg disease is identical
with that which causes infections in
many warm-water fishes, chloram-
phenicol may be the choice in treat-
ment of infections of aquarium
fishes. It sjiould be added to water
in which fish are kept at the rate of
50 milligrams per liter (190 milli-
grams per gallon of water ) . Water
should be changed once a week and
fresh chloramphenicol added.
Chloramphenicol is also available
in capsules, each containing 250
milligrams of the drug (1 capsule
per 5 liters or 1.3 gallons of water).
If fish are kept in flowing water,
flow should be stopped for 1 hour

55

OPERATING THE HATCHERY

( or for as lon^ as possible ) . Treat-
ments should be repeated at inter-
vals of several days, if needed. Use
of antibiotics in treatment of exter-
nal or internal diseases of fishes is
very recent, and the available in-
formation on this subject is scant.
Caution, therefore, is advised when
usin^ antibiotics. They should not
be used for prolonged periods of
time, (i. e. several weeks) be-
cause drug-resistant varieties of
pathogens may appear, and in such
cases antibiotics will become use-
less against them.

Internal treatment

In internal treatment, drugs are
given the fish by mouth with their
food, or in certain instances they
have to be introduced in capsules
directly to the stomach. Whenever
drugs are given with the food, it is
important to select a food of good
cohesion (or use medicated pellets)
which is readily taken by fish. This
is important, because if food is per-
mitted to remain in the water even
for a short time the drugs may
leach out. Drugs must be mixed
well with the food so that each fish
will get the ({uantity of drug pro-
portional to the amount of food
taken. Food should be fed judi-
ciously in quantities exactly re-
quired by the fish. If too much
food is given, both food and drug
will be wasted. If there is not
enough food given, the weakest fish,
which may need the drug the most,
will be deprived of it. Among the
drugs given orally are sulfonamides.

antibiotics, calomel, carbarsone, and
kamala.

Sulfonamides are most effective
in treatment of furunculosis, which
is a disease predominantly affecting
the salmonid fishes. Sometimes,
however, this disease may cause
losses among warm-water fishes.
Of the great variety of sulfonamide
drugs, those most frequently used
are sulfamerazine and sulfametha-
zine, with the possible addition of
sulfaguanidine. The effective dos-
age rate is 8 to 12 grams of sul-
famerazine daily per 100 pounds of
fish. Some workers have found
that replacement of one-third of
either of the first two sulfonamides,
with sulfaguanidine is somewhat
more effective. For best results,
treatment should start as early as
possible and be continued for about
2 weeks. In a recurrence of the
disease, treatment should be re-
peated. During the period of treat-
ment, only medicated food should
be fed to the treated fish.

Calomel and carbarsone are effec-
tive in the treatment of intestinal
infections caused by one-celled ani-
mal parasites, like Octomitus.
Either one of these drugs should
be added at the rate of 1 gram to the
pound of food. Feeding of the
medicated food should be continued
for H days, and repeated when
needed. Kamala is used for treat-
ment of intestinal tapeworms in
fislies. It can be added to food at a
rate of 1 to 1.5 percent, or given in
capsules to large brood fishes, the
dosage being 0.1 gram for each 8

56

DISEASE CONTROL

pounds of tish. Treatment with
kamala should be continued for .3
days.

Here is a list of the chemicals and
drugs that are recommended for use
in the treatment of bait fishes :

Drug

Concentration

Disease

Acriflavine

1 part per 50,000 to 100,000
parts of water.

External parasites.

Calomel

1 gram per pound of food

Intestinal infections, as

OctomiUis.

Carbarsone

do

Do.

Chloramphenicol

50 mg. per liter of water, or
190 mg. per gal.

Bacterial infections.

Copper sulfate

1 part to 2,000 parts of water,
or 1 oz. in 15 gal.

Fungus.

Formalin

1 part of 40 percent formalin
to 4,000 parts of water.

External parasites.

Gammexane

1 part per 10,000,000 parts of

Infestations with copepods

water.

(Arguliis, possibly also
Lernea) .

Glacial acetic acid

1 part in 500 parts of water. __

External parasites.

Kamala

0.1 gram to each 3 lbs. of fish_

Intestinal tapeworms.

Malachite green

1 part in 15,000 parts of water,
or y% oz. in 15 gal. of water.

Fungus.

Pyridylmercuric acetate

2 parts per 1,000,000 parts of

Bacterial infections.

technical (PMA).

water.

Quinine hydrochloride

1 part per 50,000 to 100,000
parts of water.

External parasites.

Salt

3 percent solution, or 1 oz. per

External protozoan para-

60 cubic inches of water, or

sites and fungi.

4 oz. per gal.

Sodium sulfamerazine

1 part per 1,000 parts of water.

Bacterial infections.

Sodium sulfathiazole

do :

Do.

Terramy cin

50 mg. per liter of water, or
190 mg. per gal.

Do.

CONTROL OF SPECIFIC
DISEASES

Fungus diseases

Fungus disease of fish is usually
attributed to an organism called
Saprolegnia parasitica. At the
point of infection, the fungus ap-
pears as a grayish-white fuzz. This
growth spreads rapidly over the
body surface, and the fish is some-
times almost completely enveloped
before death occurs. It is a common
disease of fish, especially in warm

waters, or in tanks and aquaria.
The focus of infection is usually
traceable to some injury which per-
mits entrance of the spores. This
disease is controlled in nature by
certain bacteria which are found
in the mud and ooze of lake and
pond bottoms. Infected fish from
tanks should be dipped for 5 min-
utes in a concentrated salt solution
(see Dipping, p. 53). In stubborn
cases, the treatment can be repeated
several days in succession. A 10-
second dip in malachite green 1 :

57

OPERATING THE HATCHERY

15,000 solution (Vs ounce in 15 gal-
lons of water) is very effective (see
also Flushing, p. 52).

Bacterial diseases

Fin rot. — This disease may be
caused by several different bacteria.
The disease is cliaracterized by a
progressive degeneration of a fin or
the tail of a fish until the entire
appendage is destroyed. The infec-
tion starts at the free end of the fin.
The diseased tissue is separated
from the uninvaded tissue by a
white line. Control of this disease
is accomplished by dipping in a
1 : 2,000 solution of copper sulfate
for 1 or 2 minutes. If the water is
hard, 10 milliliters of glacial acetic
acid should be added to 10 gallons
of water (1 fluid ounce to 30 gal-
lons) . Fish on which the disease has
progressed to a marked degree
should be destroyed, as the dip can
do little for them. Bacterial fin rot
has also been controlled with a
1 : 4,000 (8 ounces to 100 gallons of
water) solution of formalin (see
Prolonged Treatment, p. 54).

Cohmmaris. — During recent
years, many outbreaks of infections
of warm-Avater pond fishes with a
bacterium called Chondrococcus
{C'ytophaga) columnarlH have been
reported. This bacterium attacks
fish mostly at higher water tem-
peratures, like 25° to 30° C. (77°
to 88° F.). The infection is
chai-acterized by the appearance of
grayish-white spots on the head,
gills, fins, or some part of the body,
wliicli is usually surrounded by a
zoiH' with a distinct reddish tinge.

Superficially, the spots resemble
lesions produced by Saprolegnia.,
but a close inspection shows that
they lack the fuzzy appearance so
characteristic of a fungus infection.
C. columnaris can easily be identi-
fied under the microscope by an ex-
perienced person. Disease breaks
out most frequently as a result of
handling, and this can be prevented
by dipping the fish right after han-
dling for 1 minute in a solution of
copper sulfate. This chemical add-
ed to pond water at a rate of 1
p. p. m. may arrest the progress of
the disease.

Infections dropsy. — Pseudomonas
{Aeromonas) hydrophila.^ a bac-
terium commonly present in water,
causes this disease. Occasionally
more infective races (mutants) of
this bacterium appear, which are
more destructive to fishes. The re-
sistance of fishes is lessened by han-
dling, crowding, or other unfavor-
able conditions. Outbreaks of in-
fectious dropsy occur most fre-
quently in spring when the tem-
perature of water rapidly increases
and fish are still weakened by win-
ter. Sometimes up to 80 percent
of the fish may die within several
days. It is one of ihe most de-
structive bacterial diseases of warm-
water fishes.

The symptoms of this disease are
variable. Sometimes the diseased
fish may have deep boils or shallow
ulcers on their bodies. Frequently
the body is swollen and the abdo-
men filled with a watery fluid
(dropsy). Occasionally the skin
on the abdomen may become pink or

58

DISEASE CONTROL

red with some small hemorrhages.
The intestine also may show con-
gestion. Scales may stand out on
the swollen fishes. Ps. hydrophila
can be isolated from the abdominal
fluid, blood, and lesions, and iden-
tified by a bacteriologist. Frogs
also sometimes become infected
with this bacterium, and the result-
ing disease is called "red leg,"
stressing the most characteristic
symptom of this disease in frogs.

There is no known treatment for
this disease. If fish are in an
aquarium or a tank, addition of
chloramphenicol may be used.
Also feeding food that contains
chloramphenicol or terramycin
may be effective (see Prolonged
and Internal Treatments, pp. 54
and 56).

Fmmnculosis. — Produced in fish
by Bactermm. salmonicida^ this is
a disease of salmonid fishes (sal-
mon and trout), but whenever min-
nows or other warm-water fishes
are kept in water which flows from
tanks or ponds holding infected
trout, it may cause severe mortality
among them. Furunculosis has
variable symptoms. In minnows,
the most typical signs are boils or
bloodshot fins. Diagnosis can only
be made with certainty by bacterio-
logical examination of the diseased
fishes. Furunculosis, if correctly
diagnosed, can be effectively treated
by feeding the infected fish with
food containing sulfamerazine, or
sulfamethazine. Some authors
recommend replacement of one-
third of either of these two sul-
fonamides with sulfaguanidine.

which belongs to the same group
of drugs. Recommended dosage is
8 to 10 grams of sulfonamides daily
per 100 pounds of fish (see In-
ternal Treatment, p. 56).

Parasitic worms

Black grub. — Black grub, or
black spot, is caused by the larval
form of the flatworm, Neascus sp.
The jiarasite occurs on fishes as a
small black spot about 1^5 of an
inch in diameter. This black cyst
encloses a small worm which is usu-
ally limited to the scales and in-
tegument, but wdiich may occasion-
ally be found in the flesh just below
the skin. The life history of the
black grub is complicated, but is
typical of many of the parasitic
flatworms. The adult worm oc-
curs in the kingfisher. Eggs of the
Vvorm are discharged into the water,
where they hatch into small, free-
swimming organisms. These lar-
val forms swim about until they
come in contact W'ith a particular
species of snail. Then they bore
into the snail and reproduce them-
selves many times. Finally, num-
bers of free-swimming forms break
out in the water and move about
until contact with a fish is made.
They then bui-row in and encyst in
the scales or in the flesh. When
the fish is eaten by a kingfisher, the
encysted worm develops into an
adult and the life cycle is com-
pleted. It usually causes little dam-
age to the fish, but may, at times,
be jn*esent in numbers large enough
to cause death.

Klak (1940) reports a heavy

59

OPERATING THE HATCHERY

Neascus infection of fathead min-
nows in a pond at Leetown (W.
Va.). The encysted worms were
found in the abdominal cavity in
such numbers that the abdomen
was greatly distended. Mortality
was so high that a change to golden
shiners, a more resistant species,
was recommended.

The only control for this para-
site is draining the pond long
enough to kill the snails and con-
trolling the kingfisher population.
Snails in ponds can be killed
rapidly by disinfection of the pond
with chlorine (see Disinfecting
Ponds and Equipment, p. 61).

Tapeworm. — Ligula intestinalis
is a tapeworm whose last larval
stage is commonly found in the
body cavity of suckers and min-
nows, and rarely in perch, darters,
and bass. Infested fish are easily
recognized by their swollen bellies.
Worms 6 inches long have been
taken from minnows, and worms as
long as 12 inches have been taken
from suckers. The adult stage lives
in the intestines of water birds.

Minnows and suckers reared in
ponds or taken from shallow waters
along lake shores may be infested.
The parasite is known to be of wide
occurrence in the Great Lakes and
adjoining areas. Because the para-
site's eggs are spread by water
birds, and early larval forms live
in the natural food organisms of
fish, tliere is little chance for perma-
nent control, although drying and
freezing of pond bottoms may re-
duce infestation.

Other tapeworms can frexjuently

be found in the intestinal tract of
warm- or cold-water fishes. Heav-
ily infested fish become sterile,
therefore, the removal of tape-
Avorms is important in the case of
brood stock. Several drugs given
orally may be effective. McKernan
(1940) found that the addition of
1 to 1.5 percent of kamala to their
food rids fish effectively of tape-
worm. One contributor to this pub-
lication (Snieszko and Powell, un-
published ) successfully cured adult
largemouth black bass by treating
the fish for 3 days with kamala in
capsules. Each adult bass received
daily one capsule containing 0.1 to
0.2 grams of kamala, dosage being
about 0.1 gram for each 3 pounds
of fish. The treated fish eliminated
great masses of tapeworms with the
feces.

External animal parasites

Here are included such proto-
zoans as Costia, Chilodon, Tricho-
diim^ Scyphidia, Epistylis^ Ichthy-
ophthinus, and external trematodes
such as Dactylogyrus and Gyrodac-
tylu^. All of these parasites except
Ichthyopkthirius live on the surface
of the fish's body and gills and are
readily removed by salting, dipping
in glacial acetic acid, or by using
prolonged treatments with forma-
lin. I chthyophthirius differs from
the other external parasites listed
here, since in its adult stage it buries
in the epidermis of the fish; there-
fore, these treatments are not effec-
tive against it unless they are re-
peated daily until the desired
results are attained. Where water

60

DISINFECTING

flows through the pond, increasing
the rate of flow is considered the
most eft'ective means of controlling
this parasite. If fish are held in
tanks or aquariums, the addition of
hydrochloride or sulfate of quinine
to the water at the rate of 1 : 50,000
to 1 : 100,000 is recommended.
Water containing quinine should be
replaced by fresh water when the
fish are cured. Recently Schaper-
claus (1954) recommended using
acriflavine in the same way as qui-
nine. Acriflavine is believed to be
even more effective than quinine in
the treatment of Ichthyophthirius
and other external protozoans.

Copepods. — Suckei-s and min-
nows held in sluggish or warm
waters may develop raw circular
wounds with what appears to be a
slender bonelike splint projecting
from the center of each lesion. The
white splint actually is a copepod
parasite, Lernea sp., which has
burrowed head first into the flesh,
usually beneath the dorsal fin. This
parasite is common in southern por-
tions of the Lake States and is more
abundant southward.

The projecting i>ortion of the
parasite contains reproductive or-
gans which scatter eggs into the
water as the host fish swims about.
These eggs hatch into tiny free-
swimming larvae. The larvae, in
time, attach themselves to another
fish, transform their body shape to
a great degree, and burrow in.
Meehean was able to cure the infec-
tion on fancy goldfish by reducing
the pond level to a point wiiere
water flowing in and out of the pond

produced a mild current. The
young that hatched did not reinfect
the fish, and the adult parasites
dropped off after they reproduced.
Infected goldfish could be healed in
about 10 days.

Recently a chemical, gammexane,
has been recommended for treat-
ment of fish infected with the cope-
pod Argulus sp. It may also be
effective against other copepods.
It should be added to water contain-
ing infected fish at a rate of 0.1
p. p. m. and mixed well. It is rec-
ommended that after 2 to 3 days of
treatment, the water containing
gammexane should be replaced
with fresh water. Since this is a
new and little-known treatment, it
should be carried out with great
caution.

DISINFECTING PONDS AND
EQUIPMENT

The incidence of disease can be
greatly diminished or even entirely
avoided by observation of certain
sanitary measures. Some of them
will be listed here. For more detail,
see publications by Davis (1947
and 1953) and O'Donnell (1947).

If disease recurs frequently, the
hatchery must be carefully exam-
ined to determine the source of in-
fection. Most frequently the source
of infection can be found in not-
completely cured fish or in older fish
(brood stock), which may serve as
a reservoir of infection without any
visible symptoms of a disease.
Since frequent treatments are costly
and time consuming, it is often bet-

367913 O— 5€

61

OPERATING THE HATCHERY

ter to kill the diseased fish, disinfect
the ponds, and start over with
healthy stock.

In case of an outbreak of a disease
in one part of a hatchery, the in-
fected part should be isolated and
quarantined. All of the equipment
used in this part of the hatchery
should be disinfected. Ponds, also,
should be disinfected as soon as the
fish are removed.

Disinfecting equipment

For disinfection of tools and
utensils, any good disinfectant can
be used. Chlorine in the form of
hypochlorite is generally available,
inexpensive, and easy to use. The
concentration used in hatcheries is
200 p. p. m. of free chlorine. The
quantity of hypochlorite that has to
be used to obtain this concentration
can be calculated from the contents
of available free chlorine as indi-
cated on the product's label. Hypo-
chlorite in open containers and ex-
posed to moisture and light loses its
strength rapidly.

Roccal, another widely used dis-
infectant, is recommended for dis-
infection of hands, boots, nets, and
other equipment. It is sold as a 10-
percent solution. The disinfecting
solution can be obtained by diluting
1 part of commercial roccal with 100
yjarts of water. Roccal is colorless,
odorless, and harmless, if not taken
internally.

Disinfecting ponds

Ponds can be disinfected by the
addition of hypochlorite, or liquid

gaseous chlorine, to water. The
concentration of free chlorine
should not fall below 100 p. p. m.
during disinfection, which should
last at least for 1 hour. Water con-
taining chlorine is very toxic to fish
and other life. If water with chlo-
rine is kept in ponds for 2 or 3 days,
all chlorine will disappear. If,
however, water with chlorine must
be released sooner to a stream with
fish, the free chlorine should be
neutralized w i t h photographer's
hypo (sodium thiosulfate). Chlo-
rine will also kill fish parasites pres-
ent in water, as well as snails which
often act as intermediary hosts to
some fish parasites.

Drying and liming of ponds are
also good practices; however, ponds
so treated must remain completely
dry for several months to make this
practice entirely effective.

CONTROLLING PREDATORS
AND PESTS

INSECTS

Minnow ponds may become over-
populated with aquatic insects that
prey on fish fry. Of these, the bee-
tle larva called the water tiger and
the adult insect known as the back-
swinnner {Nofonecta) are the most
destructive. As both come to the
surface of the water for air, they can
be controlled by covering the ponds
with a film of oil. Kerosene, fish
oil, No. 2 fuel oil, and cod-liver oil
can be used for this purpose, as they
are not injurious to fish. The cod-
liver oil must be mixed with gaso-

62

PREDATOR CONTROL

line before use. Meehean (1937)
recommended using 10 to 12 gallons
of kerosene to an acre of water sur-
face. The same result can be ob-
tained with 4 or 5 gallons of com-
mercial fish oil. The fish oil is
sprayed on the surface to control
the thickness of the film. Kerosene
becomes too thin to be effective when
sprayed, so it is best poured along
the windward side of the pond.

BIRDS

Herons and kingfishers may cause
a heavy loss of fish from ponds.
Occasionally, the entire production
of a pond has been taken by birds.
The private hatcheryman is not al-
lowed to shoot or trap these birds;
so he must depend on scares, wires,
and fences to keep them from the
ponds.

Herons do not usually alight in
the water, and a low chicken-wire
fence close to the edge of the pond,
or very steep banks around the
pond, will keep them out. Some-
times, several wires around the
pond will work as well.

Kingfishers are attracted to
posts that overlook the water. Re-
moving all posts and dead trees
near the ponds should help to dis-
courage these birds.

The hatchery operator should
try to keep predatory birds from
his pond, as the heron spreads the
yellow grub, and the kingfisher is
host to the black grub.

SNAKES

A large percentage of the food
of the common water snake and

some garter snakes consists of fish.
The water snake has a preference
for streams but frequents fish
ponds.

Snakes can be controlled by kill-
ing all that are seen around the
ponds. The grass and weeds at
the edge of the pond should be
cut short at all times so as to de-
prive the snake of much-needed
cover. Logs, tree roots, and boul-
ders should be removed for the
same reason. Ponds that are fenced
to keep out herons should be pro-
vided with pits at intervals along
the outside of the fence to catch
snakes and turtles. Water-snake
traps are now advertised for sale
in some communities.

TURTLES

Some species of turtles are known
to be fish eaters and, consequently,
are predators if given access to a
minnow pond. As a safeguard,
all turtles frequenting a pond of
minnows should be considered pre-
dators and controlled. Turtles can
be captured with baited hooks or
turtle traps (fig. 25).

PREDATORY FISH

Predatory fish and the adults of
cannibalistic minnows must be con-
trolled in minnow ponds. As men-
tioned before, lake and river water
should be filtered to keep preda-
tory fish fry from entering a pond.
When possible, the minnow pond
should be drained dry during the
winter to kill any predatory fish
that may have escaped notice.
Ponds that cannot be drained

63

OPERATING THE HATCHERY

Figure 25. — Floating turtle trap. Tur-
tles seeking a sunning spot are tipped
into the net or wire bag.

should be treated with rotenone
before minnows are introduced and
whenever there is an indication
tliat predatory fish have become
established.

The best procedure is to apply
1.5 to 3 pounds of 5-percent rote-
none powder to an acre- foot of
water, depending: on the hardness
of the water. Ponds with hard
water, very cold water, or contain-
ing bullheads require a heavier
dosage. Emulsifiable rotenone can
be used at the rate of 1 gallon for
each 3 acre-feet of water. The
emulsifiable rotenone can be ap-
plied as it comes from the can but
the powder must be mixed with
water to form a thin batter. The
poison is usually spread evenly
over the pond with a boat and out-
b o a r d motor. The rotenone is
poured over the edge of the boat
into the propeller wash at a steady
rate. The pond should be criss-
crossed in a good pattern with

lines about 50 feet apart for good
distribution of the poison.

SALAMANDERS

The tiger salamander (fig. 26)
is abundant in many minnow
ponds and is often considered an
important predator of minnows.
Salamanders grow fast enough to
keep ahead of most minnows and
could be fish predators during the
entire period of pond life. Stud-
ies on Minnesota sucker ponds
show that the salamander is more
important as a competitor of the
sucker, than as a predator. The
stomach contents of 133 salaman-
ders of all sizes from 8 sucker
ponds was only 2.3 percent min-
n o w s . Copepods and cladocera
which are important sucker foods
made up 29.6 percent of the total
food of the salamander. Corixid
water bugs which are little used by
suckers made up 28.9 percent of
the salamander diet.

Figure 26. — The tiger salamander is
abundant in many streams and is
considered an important predator of
bait fishes. (Photograph courtesy of
the Minnesota Department of Conser-
vation.)

64

PREDATOR CONTROL

Salamanders can be controlled in
artificial ponds by keeping the pond
dry until after they have deposited
their eggs. Because the salamander
returns to the pond to lay its eggs
shortly after the ice melts, the pond
can be safely filled in late spring.
In natural ponds the salamanders
can be controlled by removing the
large gelatinous egg masses before
they hatch. The egg masses are
usually formed on sticks or weeds
in shallow water, so they are easy
to find.

Salamanders do so little harm in
sucker ponds that control is usually
not necessary. At seining time, the
dealer should sort out the sala-
manders as soon as possible because
they will gulp down large numbers
of minnows when held in such
crowded conditions.

MUSKRATS

The only appreciable damage
done by these animals results from
their burrowing in the dikes of
ponds. At times they can be seri-
ous pests, causing abnormal bank
leakage and slipping that result in
expensive maintenance costs. If a
minnow producer has difficulty
with these animals, he should con-
sult his Stat« conservation depart-
ment as to methods of control.
Most States have specific laws pro-
tecting the muskrat because of its
value as a fur-bearing animal.

CRAYFISH

In many places the crayfish (fig.
27) is considered a predator or a
nuisance in ponds, but in regions
where crayfish are used extensively
for bait, they may be an important
byproduct of minnow production,
or may rate separate ponds.

In areas where crayfish are a nui-
sance in ponds, they can best be con-
trolled at harvest time when they
can be removed at no extra cost.
Every haul of the seine will bring
in large numbers of crayfish that
should be separated from the min-
nows as soon as possible to prevent
damage to the minnows from their
claws. If crayfish removal is to be
effective, the crayfish must be car-
ried away from the pond or buried,
as those thrown up on shore will
crawl back to the pond in a short
time.

Figure 27. — The craylish is considered
an important predator in some areas.
( Photograph courtesy of the Minnesota
Department of Conservation.)

65

SOME IMPORTANT BAIT FISHES

Knowledge of the life history and
behavior of the bait fishes he is rais-
ing helps the operator achieve max-
imum production in his ponds.
This knowledge aids him in select-
ing the species for each type of
pond, in choosing the spawning fa-
cilities to be supplied, and in de-
termining the amount and kind of
fertilizer to use.

The name "minnow" is commonly
but erroneously applied to small
fishes of all species. The true min-
nows are members of a family of
fresh-water fishes, the Cyprinidae,
and have definite characteristics
that separate them from other fam-
ilies. Most bait fishes are true min-
nows, but some important species
like the mud minnow and the sucker
belong to other families. Most bait
fishes are small, but some, like the
carp, an introduced "minnow," and
the Colorado River white salmon.

attain weights of 40 to 80 pounds.
Young game and food fishes, such
as perch and pike, and which should
be called fry or fingerlings, are
often improperly called minnows.

Of the fishes used for bait, the
true minnows are most important.
They can be distinguished from
other fishes by the following char-
acters: No teeth in the jaw^s; no
scales on the head but over re-
mainder of body; no spiny rays in
any of the fins ; one dorsal fin ; less
than 10 rays in the dorsal fin ; pelvic
fins abdominal in position ; size usu-
ally small, under 6 inches (fig. 28).

Fish have definite food prefer-
ences. Many species feed entirely
on the tiny, drifting plants of the
plankton, others on animals, and
some on both; some prefer insects,
and others take whatever comes
along (figs. 29-32).

DORSAL FIN

LATERAL

BARBEL

PECTORAL FIN

ANAL FIN

PELVIC FIN

Figure 28. — A typical minnow, showing the parts used in identification.

66

LIFE HISTORY

Figure 29. — Daphnia, a pond organism
used by bait fish as food ; greatly mag-
nified. (Photograph courtesy of the
Minnesota Department of Conserva-
tion.)

SpaAvning requirements, like
feeding habits, differ for different
species. Some bait fish require
flowing waters; others do not.
Some lay their eggs on vegetation;
some lay their eggs on open gravel
shoals or under debris. Some have

Figure 30. — Cyclops, another minute
crustacean used by bait fish ; greatly
magnified. (Photograph courtesy of
the Minnesota Department of Con-
servation.)

extended spawning seasons and oth-
ers have short ones. Adequate fa-
cilities for spawning are a neces-
sity in good pond management.

To comply with natural habitat
requirements is important. Those
normally living in bog streams or
swift currents might not readily
adapt to life in ponds or holding

Figure 31. — The rotifler, Karatella;
greatly magnified. (Photograph cour-
tesy of the Minnesota Department of
Conservation.)

tanks. In general, however, most
stream or lake minnows can be
reared in ponds, and with proper
food may grow faster than in their
natural environment.

There are many species of bait
fishes, but the following pages in-
clude some of the more important
species. The culture of several
"minnow" species that are of wide

67

SOME IMPORTANT BAIT FISHES

f\ rt f

• %

)

L

O "n

Figure 32. — Some common aquatic insects and worms and their relation to bait fish.

Top row: Stonefly (food), mayfly (food), dragonfly (predator).

Middle row: Water tiger (predator), whirl-a-gig beetle (predator), canefly (food),

chironomid-fly larvae (food).

Bottom row: Leech (competitor), annelid worm (food).

distribution and that have been sue- parts of the country is treated in
cessfully introduced in various detail.

WHITE SUCKER Cafosfomus commersonnii'

Also called Common Sucker.

68

SUCKER

LIFE HISTORY

Description. — Sucking m o u t h
with thick fleshy lips on underside
of head; fine scales near head and
coarse ones on tail ; small specimens
have three large dark blotches on
each side of body ; more than 10 rays
in dorsal fin (true minnows have
less than 10) ; no spiny rays in any
of the fins.

Range. — This fish is widely dis-
tributed in the United States, oc-
curring east of the Great Plains
from northern Canada, Hudson
Bay drainage, to Labrador, and
south to Georgia, Arkansas, and
Oklahoma. It thrives under a va-
riety of conditions, but prefers
clear-water lakes and streams.

Breeding habits. — The sucker
runs upstream to spawn early in the
spring. It prefers swift water and
gravel bottoms, scattering its eggs
freely in the current. It will spawn
to some extent in lakes if there are
no outlets and inlets. Work done
in New York indicates that temper-
atures from 57° to 68° F. are best for
hatching eggs. In this temperature
range, the incubation period was 5
to 7 days. At 70° F., mortality was
high and the incubation period was
about 4 days. At 40° F., none
hatched in more than 14 days. As
many as 47,800 eggs were taken
from one female.

Food. — The sucker has diversified
feeding habits. It seems to feed on
any food that may appear in the
water. A study of 1,080 suckers
from Minnesota natural ponds
shows the average food content to
be cladocera, 30.6 percent; cope-

pods, 17 percent ; ostracods, 2.4 per-
cent; chironomid larvae, 26.4 per-
cent; miscellaneous insects, 1.5 per-
cent; rotifers, 10 percent; protozo-
ans, 0.8 percent ; nematodes, 0.6 per-
cent; and miscellaneous organisms,
10.7 percent. This list suggests
that the planktonic crustaceans are
the preferred food of the sucker, but
a closer study reveals that chirono-
mid larvae are eaten whenever they
are available irrespective of crusta-
cean abundance. Very small suck-
ers prefer small organisms but can
exist on larger forms when neces-
sary.

Importance. — The common, or
white, sucker is a popular minnow
for propagation because it is easy to
raise in large numbers, grows rap-
idly, is very hardy in the minnow
pail, and is preferred by fishermen
as a bait for walleyed pike. Suckers
are raised more cheaply in natural
ponds than in artificial because the
sucker needs a large amount of
growing space that can be provided
more cheaply in natural ponds.

PRODUCTION

The white sucker is naturally a
fish of clear waters, so ponds ^ for

1 Many Minnesot.a dealers have had no re-
turns from Slicker fry planted in natural
ponds. There are four pobable reasons for
this : 1. There may not have been ample food
for the fry at the time of planting. A question-
able pond should be fertilized with barnyard
manure about 2 weeks before the fry are
planted. 2. There may have been a large pop-
ulation of aquatic insects in the pond at plant-
ing time. The back-swimmer and the water
tiger prey heavily on fish fry and should be
killed off 2 days before the fish are planted In
the pond (p. 62). 3. The natural pond may
have had a population of predatory fish or
minnows at planting time. 4. The ponds may
not have been stocked with free-swimming fry.

69

SOME IMPORTANT BAIT FISHES

its production must be selected more
carefully than those used for other
bait species (fig. 33). Experience
has shown that the following points
are important in choosing sucker
ponds :

1. Ponds of moderate fertility usually
produce the most suckers. Sterile ponds
do not produce enough food for the fish
and very fertile ones often produce
enouKh algae to cause summer kill. Any
pond that becomes pea-soup green should
not be stocked with suckers because pro-
duction will be very small. If the pond
is over 10 feet deep and the algal bloom
is moderately heavy, the byproducts of
algal decomposition will be dispersed
widely enough to make a fair sucker pro-
duction possible.

2. Ponds with large populations of

chironomid-fly larvae, or blood worms, in
the bottom muds will produce good sucker
crops more consistently year after year
than ponds that do not have an ample
supply of these larvae.

3. The texture of the pond soil is very
important. Ponds with loam and sandy-
loam soils produce best, peat and peat-
loam ponds are average producers, and
silt and clay loam ponds are poor. The
pond soil is imiwrtant in its effect on
water fertility and the production of
chironomid-fly larvae.

4. Ponds with heavy, mosslike growths
of filamentous algae over the bottom do
not produce good crops of suckers. One
Minnesota pond always produced large
sucker crops until the filamentous algae
got started and covered the entire bot-
tom. Since then production has been
almost zero. This is possibly because
filamentous algae decompose readily and

FiGUBE 33. — A profitable sucker pond in Minnesota. (Photograph courtesy of the
Minnesota Department of Conservation.)

70

SUCKER

produce toxic ammonia just as the water-
bloom does, and because the algal mat
on the bottom may interfere with the
feeding activities of the sucker.

Collecting the eggs

Suckers and minnows that spawn
in running water are usually
stripped and the eggs are hatched
in jars. Taking eggs from the
sucker and fertilizing them is not
difficult, but considerable strength
is required. The sucker not only is
large, but it is one of the most active
and powerful fish for its size native
to our waters. On the upper Missis-
sippi and its tributaries, suckers lit-
erally swarm during May and June
over the shallow, rocky stream bot-
toms in swift water, as well as along
the rocky, wind-driven shores of
many of the northern lakes.

The fish in these spawning runs
are caught with seines or traps and
are sorted. The ripe males and fe-
males are carefully put in separate
tubs of water and the unripe fish are
released for another day. If those
selected for stripping do not give
their eggs and milt freely under
light pressure, with the thumb and
forefinger moved downward over
the abdomen toward the vent, they
should also be released. Eggs
forced from the fish by heavy pres-
sure will not prove fertile. The
males mature somewhat earlier in
the season than the females, and the
bulk of them may have moved
higher up stream than the point at
w^hich the bulk of the females are
taken, resulting in a local scarcity
of males. Both sexes would be

available, however, if the fish are
caught as they run up the stream
and are put into a suitable holding
pond until needed for stripping op-
erations. In any event, eggs should
not be taken unless a ripe male is im-
mediately available for fertilizing
them.

The female is held over a damp-
ened pan into which the eggs are ex-
pressed (fig. 34). Immediately
after the eggs are taken, a male is
stripped of his sperm ; the milt and
eggs are thoroughly mixed by
gently swirling the pan. Four or
five pairs of fish may be stripped
into one pan providing each batch
of eggs and milt are thoroughly
mixed immediately after stripping.
After a lapse of 2 or 3 minutes,
water may be slowly added to the
pan and the stirring continued at
intervals by rocking the pan gently
to and fro, swirling the water.

The milt can now be washed out
by frequent changes of water (fig.
35) . If the eggs have a tendency to
stick together in clumps, a cup of
muck or corn starch of the consist-
ency of bean soup should be added
as the eggs are stirred (fig. 36).
The muck or cornstarch is then
washed out with the milt.

After being washed, , the green
fertilized sucker eggs are trans-
ferred to a tub to harden (fig. 37).
The tub is placed in cold creek water
and is shaded from the sun. Peri-
odically the eggs are stirred gently
and the water is changed. After 2
hours the eggs are hard enough to
withstand the rigors of transporta-
tion to the hatchery.

71

SOME IMPORTANT BAIT FISHES

I'^iGURE 34. — A female sucker is stripi)ed
of its eggs. (Photograph courtesy of
the Minnesota Department of Con-
servation.)

Artificial hatching

At the hatchery, the eggs are
transferred to Meehan hatching
jars (fig. 38) , Usually 2 or 3 quarts
of eggs are placed in eacli jar, and
the water is adjusted so the eggs are
in constant hut gentle movement
tliroughout the lower portion of the
jar. For best results, the water
shoukl contain sufficient dissolved
oxygen for the eggs, but should be
free of air bubbles because the bub-
bles adliere to tlie eggs and carry
them up and out of the jar. Lengtli
of hatching time depends on tem-
perature of the water. Eggs will
hatch in 4 to 6 days in water warmer
than 65° F., in 10 to 15 days in
water of 50° to 60°, and not at

all in water colder than 50°. Min-
nesota hatchery operators prefer to
start the eggs at 50° to prevent
clumping, and then increase the
temperature to 55° or 60° for hatch-
ing, if possible. In some States,
the water from lakes and streams
reaches optimum temperature in
time to be used in the hatching
battery.

Fortunately, sucker fry stay in
the jars after hatching, and do not
swim out with the water until they
are about 5 to 10 days old. Conse-

FiGURK Hry. — The milt is washed away
with frequent changes of water.
( Photograph courtesy of the Minnesota
Department of Conservation.)

72

SUCKER

Figure 36. — A eup of muck is added to
keep the eggs from clumping. (Photo-
graph courtesy of the Minnesota De-
partment of Conservation.)

Figure 37.— The fertilized eggs are trans-
ferred to a tub to harden. (Photo-
graph courtesy of the Minnesota De-
partment of Conservation.)

quently, the fry can be held in the
jars until they are free swimming,
and are not put in the pond until
they are strong enough to search
for food. Because the suckers stay
in the jar and settle to the bottom
when the water is turned off, it is
very easy to determine the number

Figure 38. — Hatching sucker eggs.
( Photograph courtesy of the Minnesota
Department of Conservation.)

on hand and the number to be used
in each pond. The fry can be
poured into a glass measure gradu-
ated in ounces and measured after
they settle. Counts made in Minne-
sota indicate that there are 2,720
5-day-old sucker fry per ounce.
Suckers grow rapidly in ponds. In
60 days they average 2.8 inches and
may reach a length of 3,5 inches in
that time. The following table

73

SOME IMPORTANT BAIT FISHES

shows the rate of growth of young
suckers in ponds:

Number
of days

Length
of fish
(inches)

Number
of days

Length
of fish
(inches)

10

20

30

0.7
1. 1
1.5

40

50

60

2.0
2. 4
2. 8

Sucker pond production is usu-
ally expressed in pounds and
wholesale sales are usually in gal-
lons. The following table presents
the number of suckers of various
sizes per pound and per gallon:

Length
of fish
(inches)

Number of
fish per
pound

Number of
fish per
gallon »

1

4,250

1, 120

440

220

118

70

46

31

22

16

12

10

8

34, 000

1.5

2

8,960
3, 520

2.5

1, 760

3 - . -

944

3.5 ---

560

4 _ _

368

4.5

5

5.5

6

248

176

128

96

6.5

7 --

80
64

' 1 gallon equals 8 pounds.

Stocking the ponds with fry

While it is important for the op-
erator to know how many fry per
acre to stock in each pond, there
is little exact information on the
subject. Some years ago the Min-
nesota Bureau of Fisheries set an
arbitrary figure of 40,000 fry per
acre, because that was a fair divi-
sion of the fry available for dis-

tribution. Experience has since
shown that this stocking rate is
satisfactory. Recent studies indi-
cate that certain ponds tend to
produce only so many fish no mat-
ter how many are stocked. Of
course, understocking produces
fewer fish, but overstocking wastes
fry. If the supply of fry is lim-
ited, the dealer should experiment
until he knows the optimum stock-
ing rate for each of his ponds.
For example, when a Minnesota
pond was stocked with 69,000 fry
to the acre of water, the survival
was 17 percent; when 51,000 fry
were stocked the survival rate in-
creased to 27 percent; and when
37,000 fry were stocked the sur-
vival reached a peak of 40 percent.
The number of fish produced per
acre during the 3 years was 12,000,
14,000, and 15,000 fish of pike-bait
size. The survival rate for suck-
ers in all Minnesota ponds under
observation during these 3 years
averaged 22 percent and reached a
high of 50 percent.

Dealeis who are confronted with
seasonal markets which require
fish of acceptable size may find
that it is not advisable to produce
the maximum number of suckers
in a pond. Studies of natural
sucker ponds in Minnesota have
shown a very definite relation be-
tween the number of fish produced
in a pond and the size the fish will
be in 60 days. As the number
]>roduced in the pond is depend-
ent on the number of fry stocked,
the dealer must decide before
stocking time the size of fish he

74

SUCKER

wishes to raise and stock accord-
ingly. The following table shows
the relation between the number of
fish produced in some Minnesota
sucker ponds and the size of the
fish at 60 days:

Number of fish
produced per acre

Average length
at 60 days

19, 000
8,000
4,000

Inches
2

2.5
3

These values may not hold true
in other areas, so each dealer will
have to study his ponds and de-
termine the prevailing relation-
ship. Of course, the stocking rates
necessary to produce certain num-
bers of fish will vary with each
pond according to the survival rate
that exists in that pond.

The dealer who knows these re-
lationships for his ponds will be
able to stock some ponds lightly
to produce bait for midsummer.
Ponds stocked moderately will
produce the same size bait for late
summer, and tliose stocked heavily
will produce small fish that can be
held over winter for the early
summer season in the following
year.

Operator that do not know the
stocking requirements of their
ponds well enough to build a grad-
uated series of populations that
will produce pike-bait sized suck-
ers during the entire fishing season
can adjust the pond populations
by moving fish from one pond to
another. By a system of periodic

test nettings, the dealer can deter-
mine the growth rate of the fish
in each pond. By moving fish from
one pond to another, he can re-
lease some populations for faster
growth and can crowd others for
slower growth.

In actual practice, the operator
tries to obtain the desired minnow
population in each pond by regu-
lating the stocking rate, and then
compensates for errors in judg-
ment and seasonal variations in
the survival rate by moving fish
from one pond to another. When
this program is used in conjunc-
tion with an overwintering pond,
a year-round supply of pike-bait
sized suckers can be produced.

Fertilizing sucker ponds

As most natural ponds produce
enough water fleas to feed all the
suckers the pond will hold, fertili-
zation is usually not necessary and
should be avoided whenever pos-
sible. A number of Minnesota
ponds have been operated for 6 or
7 years without fertilization and
are still producing good crops of
suckers. Suckers seem to grow
faster and more consistently when
feeding on chironomid-fly larvae
than when feeding on water fleas.
If the fish in a pond are growing
very slowly, the pond should be
fertilized with barnyard manure
or dried sheep manure to increase
the number of chironomids in the
bottom muds (see Fertilizing the
Pond, p. 24).

Commercial inorganic fertilizer
should be used sparingly on north-

75

SOME IMPORTANT BAIT FISHES

ern natural ponds because the
pliosphorus tends to produce heavy
algal blooms that may result in
fish kills. In very fertile ponds,
the control of algae with copper
sulfate may be more important
than fertilization (see table, p.
47, for amount to use).

Harvesting the fish

Natural ponds can be harvested
most efficiently with a large seine
that is set out in a semicircle from
a boat and pulled in slowly to a
good landing beach. When the
net reaches the shore, it is bagged
and moved quickly to deeper water
so the minnows will not smother
or choke on silt. The minnows are
transferred to a floating live box
us soon as possible, and all turtles,
salamanders, and crayfish are
thrown out. If the minnows are
uniform in size and are large
enough for pike bait, they are
loaded into a tank of fresh water
and hauled to the bait shop. If
the haul produces large numbers
of undersized minnows, the fish
are put in a slat grader (fig. 23)
and the small ones returned to the
pond for further growth. The
pond is then reseined at periodic
intervals until further hauls are
not practical. The minnows that
have been missed can be trapped
under the ice during the early part
of the winter.

The time of harvest for each pond
will depend on the seasonal market
and the size of the fish being raised.
In Minnesota, the sucker harvest
starts during the last week of July

and continues until September.
The only ponds that have not been
harvested by that time are those
producing fish to be held over win-
ter. In areas where winter spear-
ing is allowed, the cash return from
a poor pond can be improved by
holding the fish until October or
November, when they can be sold as
decoys for spearing. Higher prices
can be obtained for them at that
time than if they were sold as pike-
bait-sized minnows in the summer.

While the production of sucker
ponds varies with pond conditions
and pond-management methods, the
average production of sucker ponds
in Minnesota was 10,000 nsh per
acre for 26 pond-seasons, with a
high of 25,000 and a low of 1,500.
The average was 165 pounds to the
acre, with a high of 490 pounds and
a low of 6 pounds. These produc-
tion figures are far below the yield
goals set in some publications on
minnow propagation, but the ponds
still are considered very practical.
The cost of operation was low and
the margin of profit was high.

In most sucker ponds, the pound-
age of fish produced can be greatly
increased by cropping and grading
the fish periodically. On the aver-
age, the production of Minnesota
sucker ponds was increased 75 per-
cent by cropping. When the ponds
were cropped twice in a season, the
poundage increase was only 5 or 6
percent, but when the ponds were
cropped 6 to 8 times, the poundage
increase was as high as 140 percent.
This means that if the dealer har-

76

SUCKER

vests all of the minnows from a
pond the first day he seines, large
numbers of the suckers will be small
and will have to be sold as crappie
bait. If the dealer removes only
the pike-bait size each time and al-
lows the small fish to stay in the
pond and grow, he will be able to
sell the entire production as pike
bait. The number of times a pond
can be cropped will depend on the
cost of seining and the value of pike
bait versus crappie bait.

Holding suckers over winter

In the Northern States, where 3
feet of snow and 20° -below-zero
weather are common, propagation

ponds are not practical for over-
wintering suckers. The fish must
be seined or trapped and moved to
holding ponds supplied with run-
ning w^ater (fig. 39). River- w^ater
ponds are preferable to those fed
Avith spring water, because the river
water supplies some natural food
and the minnows are in better condi-
tion in the spring. In either type
of pond, the fish must be fed arti-
ficial food, but less food is needed in
river-water ponds than in spring-
fed ponds. Suckers feed readily
on moist meat scrap or fish-meal
mash thickened with middlings and
formed into fair-sized balls. The
balls are dropped to the bottom of

Figure 39. — A winter holding pond supplied with river water. ( Photograph courtesy
of the Minnesota Department of Conservation.)

367913 0—56-

77

SOME IMPORTANT BAIT FISHES

the pond and left until consumed.
Additional food should not be added
until tlie tirst lias been cleaned up.

Even with good artificial feeding,
suckers held over winter in hold-
ing ponds will be thin the following
spring. The best way to fatten

them is to place the fish in shallow
natural ponds that have a good sup-
ply of natural foods. Fish that are
about 2.5 inches long will soon grow
to pike-bait size and those that are
3.5 inches will increase to bass-bait
size by June or July.

FATHEAD MINNOW Pimephales promelas

Also called Tuffy Minnow.

MALE

.^,.'«f'"^''"'?***^*'

#

.-4^m^

FEMALE

LIFE HISTORY

Description. — First obvious ray
of the dorsal fin thickened so that
it stands out; mouth small, termi-
nal, and upturned; scales small and
crowded behind the head; back
rounded and arched; lateral line
only on anterior half of body.
Breeding male with black head;
soft swollen pad on top of neck re-
gion; bleeding tubercles on snout
and under the chin. Lining of body

cavity black ; intestine two to three
times body length.

The males are larger than the fe-
males and reach a maximum length
of 31/^ inches.

Range. — The fathead is generally
distributed throughout southern
Canada and in the Ignited States
from Lake Champlain west to the
Dakotas and south to Kentucky and
the Kio Grande River. In north-
ern AVisconsin and Michigan, it

78

FATHEAD MINNOW

Length of fish
(inches)

Number

of fish per

pound

Number

of fish per

gallon '

1

1.5

2

2.5 -_-

2,600

740

300

150

84

52

34

20, 800
5,920
2,400
1, 200

3__ . - .

672

3.5

416

4

272

frequents boggy lakes, ponds, and Fathead production is usually

streams. In southern Wisconsin, it expressed in pounds and wholesale
is found commonly in small ponds minnow sales are usually in gal-
and silty streams. Ions. The following table presents

Breeding habits. — The males bear the number of fatheads of various
pearl organs on their black heads sizes to the pound and the gallon:
and soft, swollen pads on their
backs during the spawning season.
The spawning season extends in
some localities from May until the
latter part of August. A tempera-
ture of about 64° F. seems necessary
before spawning begins. The fe-
males may reach maturity and be-
gin spawning the following spring
at an age of 1 year. The eggs are
deposited on the underside of many , j g^i,„„ ^^^^,3 g ^^^^^^
objects in a pond. Several females

may deposit their eggs in a nesting ^ ^^^^- " ^he fathead minnow
, . , . , 1 J J u feeds mainly on zooplankton and

site which IS zeaJously guarded by . -^ ^

insects
one male. From 36 to 12,000 eggs . * „, . .

, , 1-1 .7 Importance. — ihis minnow is a

have been deposited at one site in 1 u -x i; c i, • n/r-

^ . popular baat tor panhsh in Minne-

a circular or oval spot. A single ^^^^ j^ ^^^ ^^^ ^^^^ f^^ pij^^

female has yielded 4,144 offspring ^^^^^-^^ ^^^^^ ^^^^^^ gp^^i^g ^^.^ j^^t

in 11 weeks, and spawned 12 times, available. After the early spring

The eggs hatch in 41/9 to 6 days, seining of "shiner" minnows, the

The older fish in a pond should be fathead minnow is probably the

used for bait when they have most easily obtained bait fish in the

spawned, as they die soon after. State. It grows well in small ponds

The rate of growth of the young and is easily managed anywhere in

fathead under normal conditions is the United States. More than

as follows : 200,000 fish (328 pounds) have been

raised to the acre of water.

PRODUCTION

The fathead minnow is the most

Num-
ber of
days

Length
of fish

Number
of days

Length
of fish

10

20

30

40

50

60

Inches

0. 20
.40

.58
.76
.98

1. 15

70

80

90

100

110

120

Inche,"
1.35
1.53
1. 75

1. 95

2. 15
2.32

widely and abundantly propagated
bait minnow in Missouri and other
Southern States, but in the Lake
States public waters supply enough
of these minnows to satisfy local
demands. The mature fathead

79

SOME IMPORTANT BAIT FISHES

minnow ranges in length from 1^/2
to 4 inches, the male being con-
sistently larger than the female.
The life span of the hatchery-
reared fathead minnow is from 12
to 15 months, depending on the size
of the fish at maturity. It is quite
certain that during the early
spawning season a large majority
of the males die within 30 days after
the onset of spawning activities,
and that a large percentage of the
gravid females die within 60 days.
Immature fatheads, ranging in
length from 1 to 2 inches, even
though a year old will die shortly
after they become gravid at the
age of about 15 months. It has
been noted that a small percentage
of the adult hatchery-reared fat-
heads are sterile, and also, that
these fish live longer and grow
larger than the fertile fish.

In Missouri, the fathead is com-
mercially produced by two types of
culture: intensive and extensive.
Intensive culture refers to the op-
eration of hatcheries where large
populations of fish are fed artifi-
cially. Extensive culture refers to
hatchery operations where smaller
fish populations are fed natural
foods produced by fertilization.
Both methods have merit, depend-
ing on the type of water available
at the hatchery site. Intensive fat-
head culture requires much more
labor and initial capital expendi-
ture than does extensive; however,
fish may often be produced in
greater numbers and at lower cost
by the intensive type of fish farm-
ing.

Intensive culture of fatheads

To practice intensive fish culture,
it is necessary to have a source of
flowing, cool water from a spring or
well. The ponds should not be
larger than 1 acre or smaller than
1/4 acre. The depth of water should
range from 2 feet at the shallow end
to 6 feet at the drain, and average
about 3 feet deep. The pond
should be equipped with a control-
lable inlet and similar bottom
drain. To raise fatheads profit-
ably, it is necessary to have at least
6 ponds available for propagation,
and it is much more economical, as
far as production costs are con-
cerned, to have 12 to 15 ponds. In
every unit of 6 ponds, it is desirable
to use only 2 for reproductive pur-
poses, leaving the remaining 4 for
growing ponds. The ponds to be
used for reproductive purposes
should be ballasted along two banks
with rocks ranging in size from 6
to 12 inches in diameter, or with
tile (fig. 40). This construction
should extend from about 6 inches
above the planned normal water
level to a depth where the rocks
will be covered by about 2 feet of
water. The purpose of this instal-
lation is to provide adequate
spawning facilities for the fat-
heads; at the same time, it offers
considerable protection to the levees
against pond erosion.

The brood ponds should be
stocked in the early part of April,
and the breeders should consist of
both mature and immature fat-
heads in ratio of about 00 percent

80

FATHEAD MINNOW

Figure 40. — Four-inch tile used for spawning devices. (Photograph courtesy of the
Ohio Department of Conservation and Natural Resources. )

adult to 40 percent immature fish.
Both adults and juveniles are used
as breeders because of the short life
span of the fathead. Since the
larger fish will die shortly after the
onset of spawning, it is necessary
to provide immature, developing
fish to have spawners later. In this
way, one can be sure of a continu-
ous, uninterrupted supply of newly
hatched fry. The brood ponds
should be stocked at the rate of 15,-
000 to 25,000 fish to the acre of
water.

Spawning. — In Missouri, fat-
heads normally start spawning ac-
tivities during the latter part of
April or at a time when the pond-
water temperature reaches 65° F.
They spawn intermittently
throughout the summer, providing
the water temperature does not rise
above 85°. When this temperature
is reached, spawning ceases, and is
not resumed until the temperature
is lowered by prevailing weather

conditions or by an increase in the
flow of spring water into the pond.
Sometimes, during the warm
summer months when the surface
water temperatures rise above the
80° to 85° F. range, the breeding
fatheads will conduct their spawn-
ing activities at lower depths than
normally to attain a cooler stratum
of water. The water at this level
(2 to 8 feet below the surface) fre-
quently is low in the concentration
of dissolved oxygen. Even though
the breeder fatheads can tolerate
the low oxygen content, the develop-
ing eggs cannot; and subsequently,
they all will die before the incuba-
tion period is completed. To coun-
teract this condition, the fathead
minnow grower must keep his
brood ponds free from rich organic
deposits, either by reducing the
amount of artificial food supplied
to the breeders, by reducing the
amount of fertilizer, by increasing
the incoming spring- water supply.

81

SOME IMPORTANT BAIT FISHES

or by using a combination of all
three. Fathead brood ponds aver-
aging an acre in size should have a
minimum incoming flow of 25 gal-
lons of water a minute during the
warm summer months.

During the latter part of April
when the water temperature ap-
proaches 65° F., spawning activity
can be observed. AYithin a few
days, small fry will be seen swim-
ming near the surface, a few feet
out from shore. As soon as these
small fish become numerous, they
can be captured by a small bobbinet
seine and transferred to the grow-
ing ponds. The stocking rate in a
growing pond should range between
300,000 and 600,000 fry for each
acre of water. At this rate of
stocking, the successful operator
will harvest a minimum of about
150,000 salable fathead minnows
annually for each acre of water.

Growing -pond operatimi. — Dur-
ing the first few weeks of life after
the fry is transferred to the grow-
ing pond, its rate of growth is very
rapid, and sometimes individual
fish attain a length of li/^ inches.
Within 8 to 12 weeks, many of these
first-generation fish will mature and
begin to spawn. When this occurs,
and it frequently does, the propa-
gator is confronted with a major
problem: If he allows this repro-
ductive activity to progress unat-
tended, he will soon find that the
growing pond is overstocked and
that all of the fish are stunted.
When this situation arises, there are
two corrective measures available.
One is to remove the excess fry by

seining or by draining the pond,
and transfer the fry to another
pond or destroy them. The other
solution is to introduce predacious
species, such as the creek chub or
the golden shiner, to forage on the
small fatheads. This method
should not be used unless a minnow
propagator has had a number of
years of experience in fish-cultural
work, because he may find that his
introduced predators are too effi-
cient at control, resulting in nearly
a total loss of fathead production
for the pond. If it becomes neces-
sary to resort to this method of
population control, a successful
stocking rate is 50,000 feeder (1- to
2-inch) creek chubs or golden shin-
ers for each acre of water.

Intensive culture of fatheads re-
quires many daily tasks. The water
level should be checked each day in
the ponds assuring the operator
that both the inlet and outlet valves
are in operation. It is necessary to
feed the fish each day and to fer-
tilize the pond when food alone
will not maintain a desirable plank-
ton bloom. A productive pond
should have a plankton turbidity in
the water sufficient to blank out a
white surface at 12 inches. A feed-
ing ratio demonstrated as success-
ful for fatheads consists of 6 parts
gray shorts, 1 part low-grade flour,
and 1 part cottonseed meal. This
diet is fed at the rate of 1 pound of
food for every 20 pounds of fish in
the pond. By feeding only a few
pounds of feed at first to a pond con-
taining fatheads, an observing fish
culturist can easily determine each

82

FATHEAD MINNOW

day how much food is to be applied
to eacli pond. If the plankton
bloom remains about the same in the
water from day to day and the fish
are growing, then the amount of
food is sufficient. If the plankton
bloom becomes too intense and the
fish continue to grow, then he is
feeding too much; or if the fish are
not growing, the amount of food is
too small. At the end of the grow-
ing season, a successful propagator
should not have used more than 1
pound of food for each 20 pounds
of fish in any 1 day during the peak
of growth. Also, if his operations
were successful, he should not have
used more than 6 pounds of food to
produce 1 pound of salable fat-
heads.

When about 50 percent of the fat-
heads (by weight) in a growing
pond attain salable size (11/2 inches
or more in total length), it is de-
sirable to remove as many as pos-
sible by trapping, seining, or by
draining the pond, and to place the
fish in a pond by themselves. To
drain a fathead pond during the hot
summer months, it is necessary to
pull the water level down to about
1/5 of its original volume and to
triple the incoming flow of cool
water, or, at least, to increase the
flow until all of the w^ater remain-
ing in the pond has a temperature
below 80° F. If the water tempera-
ture in a pond cannot be lowered to
this extent, it is better to seine or
trap out as many of the salable fish
as possible and to leave the others
in the pond, rather than to run the

risk of losing most of the fish by
trying to get them all out.

Extensive culture of fatheads

The extensive culture of fathead
minnows employs the use of much
larger ponds than are used in in-
tensive culture. Locating the site
for a hatchery of this type is rela-
tively easy, since the water supply
is not too important ; however, it is
necessary to locate the hatchery on
soil that is composed of a tight clay
loam capable of holding water. The
source of water is provided by rain-
fall, and the ponds are strategically
located to pick up surface runoflf.
The design of the hatchery usually
follows a characteristic pattern. It
consists of one or more large (20 to
30 acres in surface area) reservoir
ponds having a maximum depth of
15 to 20 feet, surrounded on the
lower-gravity side by several small
(14- to 1-acre) ponds.

The smaller ponds, in turn, are
filled with water acquired by grav-
ity flow from the larger pond above.
In instances when the annual rain-
fall is not sufficient to fill the reser-
voir ponds, some operators resort to
the use of a pumping system, ob-
taining their water from a nearby
stream. The large reservoir ponds
usually have a bottom drain and an
emergency high-water overflow\
The small ponds are supplied w4th
water from the large ponds by
means of a series of contour ditches.
Very few of the smaller ponds have
bottom drains, and the operator
must cut a hole in the levee to drain
the pond, siphon the water out, or

83

SOME IMPORTANT BAIT FISHES

resort to a mechanical pump.
About the only advantage of this
type of hatchery construction is its
relatively low initial cost and the
ease with which the site can be ob-
tained. The disadvantages are that
during the warm summer months
the operator must supply the ponds
with cold water from a deep well or
provide a holding station where
cold water is available to store his
salable minnows.

In the actual operation of an ex-
tensive type of minnow hatchery
for fathead production, it is not
necessary nor is it desirable to bal-
last the banks of the pond with
rocks for the breeding fish. Usually
the large reservoir pond is used for
this purpose, and the water level
may fluctuate as much as 10 feet
during a season. Also, these large
ponds usually contain enough rocks,
roots, and other debris to provide
sufficient spawning structures for
the number of breeders introduced.
In stocking a pond with breeders,
about 4,000 fish per acre are used,
consisting of about 60 percent
adults and 40 percent juveniles.

When the water temperatures in
the reservoir pond reach 65° F.
spawning occurs, and within a
week or 10 days fry appear on
the surface. Within 8 to 4 weeks,
the fry should be sufficiently large
and abundant enough to warrant
transfer, by trap net or bobbinet
seine, to the smaller growing
ponds. Since there is no assur-
ance of an incoming supply of
fresh water, the artificial feeding
of both the breeders and the fish

in the growing pond has to be
quite restricted. The same rule
applies to fertilizing the ponds.
During the midsummer period in
Missouri, the water temperatures
of reservoir-type ponds usually are
too high for continued fathead re-
production. At this season, it is
desirable to fertilize both the
brood ponds and the growing
ponds with a combination of su-
perphosphate and cottonseed meal
ill equal proportions at the rate
of 25 pounds an acre every 10
days, or until a plankton turbidity
colors the water sufficiently that a
white object cannot be distin-
guished at 114 feet. If the pond
becomes too rich in organic mat-
ter, it is quite possible that all of
the fatheads will die from oxygen
depletion. At best, it is more
practical to fertilize sparingly, and
allow the natural fertility of the
soil to determine the productivity
of the pond.

Harvesting and storing the fish

If some of the fathead minnows
attain a salable size during the
summer months, they can be re-
moved by trapping or seining. In
the fall or at any time during the
cooler seasons of the yeai-, the pond
can be drained and the entire pop-
ulation removed. These fish in
turn can be graded as to size and
stored for future sales, or they can
be placed in different ponds for
additional growth. The drained
ponds can again catch the surface
runoff, thus storing the next year's
water supply.

84

CREEK CHUB

A minnow producer, using in-
tensive techniques, should be able
to harvest from 200 to 300 pounds
of salable minnows from each acre
of water in production. This
poundage converted into numbers
of fish would represent from 40,-
000 to 70,000 fish.

When removed from ponds, fat-
head minnows should be placed in
cool water for hardening before
they are sold. The w^ater temper-
ature in the storage vats should
not be allowed to rise above 70° F.
during the summer months, and
the fish should not be confined at
this temperature for more than a
v/eek. If the operator needs to
store the fatheads for a longer
period, it is desirable to reduce the
water temperature to 65° F. Fat-
head minnows can tolerate a 20°
temperature change within a few
minutes without any harmful ef-
fects. Also, these fish can stand

excessive icing during transit in
warm weather.

Grading

In grading the fathead minnow
for sale in Missouri, a box con-
structed of %6"ii^ch aluminum bars
has proved satisfactory. The
mechanical graders are made in
two sizes: One, constructed to al-
low the small unsalable fatheads
to pass through the openings, has
a clearance between the aluminum
bars of i%4 inch; the other, to
separate the larger size from the
smallest salable size, has a spacing
of i%4 inch between the bars (see
fig. 23). In using these graders,
two size groups of salable fish are
obtained. The first group ranges
in length from li/^ to 2 inches and
averages about 325 fish to the
pound. Fish of the second size
group are from 2 to 31^ inches in
length and average about 225 to
the pound.

CREEK CHUB Semofi'/us atromaculatus

Also called Horned Dace.

LIFE HISTORY hidden just above corners of mouth

Desenption.—Blsick spot at base in groove behind underjaw; scales

of dorsal fin ; mouth large, extend- smaller and more crowded at front

ing back to below eye ; small barbel end of body ; color, olive green on

85

SOME IMPORTANT BAIT FISHES

top, steel blue on sides, white on
belly; size of females to 5 inches,
males to 11 inches.

Range a/tid breeding hahifs. —
This minnow is found most often
in creeks and rivers from Montana
and Xew Mexico east to the Atlan-
tic coast and south to Florida. The
creek chub, sometimes called the
horned dace because of the tuber-
cles the males develop during the
breedino; season, spawns during
April, May, and June in small
creeks, on gravel beds at the base
of pools, or at the head of riffles.
The male prepares and guards the
nest during the breeding season.
The young fish make an excellent
growth in the first year, reaching
a length of 3I/2 inches by Septem-
ber. Those maturing late in the
fall spawn the following season.

Food. — The creek chub seems to
eat anything that comes its way.
It has been known to feed on algae,
vegetable matter, aquatic insects,
terrestrial insects, crayfish, small
fish, fish eggs, chub eggs, snails,
and small mollusks, and it oft^n
rises to a trout lure. Sometimes a
chub stomach will contain only sur-
face drift. A study of 37 stom-
achs taken from fish collected in
the eastern and midwestern United
States showed the average percent-
age of the various food items to be
as follows: Insects, 51.3; mollusks,
3 ; crustaceans, 0.8 ; fishes, 5.4; cray-
fish, 3; annelids, 2.1; surface drift,
26; algae, 2.8 ; plants, 4.6; vegetable
debris and plant seeds, 1. ~

Importance. — The creek chub is
excellent bait for pike and panfish.

Though it spawns in moving wa-
ters, it grows very well in ponds and
slow-moving streams. The adults
strip easily and the number of eggs
is relatively large. This fish is ex-
ceptionally suited to production in
large numbers in artificial ponds.

PRODUCTION

The tenacity of life of the creek
chub makes it a good minnow for
handling, holding, and transport-
ing. It can tolerate, to a consider-
able degree, exposure to sudden
changes in water temperature, but
the culture of this species is not an
easy task. A suitable spawning
area (running water in a gravel-
bottomed stream) must be provided
where natural spawning can occur,
or the breeders must be stripped
and the fertilized eggs incubated
in a hatchery.

Preparing the spawning raceway

When selecting a location for a
creek-chub hatchery, it is most im-
portant to formulate plans for the
number of minnows to be raised, so
as to determine whether a sufficient
volume of water is available at the
location to operate the needed num-
ber of raceways and rearing ponds.

The general layout of an area
for the culture of creek chubs con-
sists of a stream emptying into a
pool. The stream provides the
spawning space, and the pool acts
as a refuge area for the breeders
during the spawning season and
later as a collecting basin or a rear-
ing pond for the newly hatched fry.
In Ohio, a successful raceway pre-

86

CREEK CHUB

pared for the propagation of creek
chubs consisted simply of a gravel-
bottomed stream and a base pool
confined within the basin of a pond
covering an area 143 feet long, 13
feet wide, and from 1 to 3 feet deep.
Starting at the inlet, the upper 24
feet of the pond was filled with fine
soil to create a steeper slope on
which a meandering channel (27
feet long, 27 inches wide, and 2 to
10 inches deep) was prepared. At
places in the dirt fill where there
was likely to be some washing by
current action, heavy reinforcing
material was used. The banks and
bottom of the channel were covered
with a heavy layer of gravel.
Water supplied by an 8-inch inlet
passed down the stream channel
and into the base pool below that
was formed by impounding the
water in the remaining portion of
the original pond basin.

In Michigan, a successfully used
creek-chub spawning raceway was
built within the basin of a pond, and
likewise consisted of a stream and
base pool ; however, the design of
the stream was radically different
from that used in Ohio. The se-
quence of the Michigan construction
was as follows : (1) Excavating the
main channel; (2) installing refuge
zones at 25-foot intervals along the
stream; (3) surfacing the entire
raceway with gravel; (4) installing
splash boards (check dams) at 25-
foot intervals; (5) regulating the
stream flow, height of the splash
boards, and the water level of the
base pool; (6) placing covers over
the refuge pits; and (7) erecting

netting over the stream bed for con-
trol of predatory birds.

The main channel (6 feet wide, 1
foot deep, and 300 feet long) was
dug within the basin of a 1.8-acre
pond. Starting at the inlet — fol-
lowing along the base of one of the
dikes — the excavation gradually de-
scended (an 8-inch fall per 100
lineal feet) into the basin of the
pond. The materials removed from
this ditch were placed on both sides
of the channel, forming 1.5-foot
banks. At intervals of 25 feet
along the course, rectangular pits,
2 feet deep, 3 feet wide, and 8 feet
long, were prepared. These pools,
referred to as refuge zones, crossed
the streambed and extended into one
of the banks for a distance of a.bout
4 feet (fig. 41, upper). That por-
tion of the refuge zone extending
into the bank was curbed to prevent
its filling by erosion.

At this point of construction the
entire stream, including those por-
tions of the refuge zones lying
within the channel and both banks,
was surfaced with a 6-inch layer
of washed gravel (l^- and 3^-inch
screened stones in equal propor-
tion). About 38 cubic yards of
gravel were used to surface the 300-
foot raceway. Immediately after
the spreading of the gravel, splash
boards (fig. 41, lower) were in-
stalled across the channel at each
refuge zone. These boards were
driven into the bottom soil to a
depth of 1.5 feet and were exposed
about 3 inches above the gravel.
The purpose of the splash boards
was twofold : (1) To act as a break

87

SOME IMPORTANT BAIT FISHES

COVER OVER

^iLji'2Z:!:^Jf!li:

^OjMBM

y >^r^>-V:*"<'''''^W'^-^^;^-*?*'*^^' * **"f^

25 —

Figure 41. — Typical raceway construction for spawning creek chubs. Upper : Dia-
grammatic view of streambed and shelters. Lower : Cross section of spawning
area. (Diagrams courtesy of the Michigan Department of Conservation.)

against the continuous current —
resulting in the formation of areas
of slow and fast-moving water and
thus simula.ting conditions i n
spawning areas in natural waters;
and (2) to prevent the refuge pools
from being filled by washing gravel.
To determine to what degree these
splash boards were accomplishing
their purpose, the inlet valve of the
pond was opened to allow 1.5 cubic
feet of water per second to flow
down the stream channel as a test.
Some splash boards projecting too
high above the streambed (forming
barriers) were lowered; others, too
low to be effective in checking the
current and preventing wash, were

raised to the desired height. The
outlet valve was then closed and the
water allowed to accumulate within
the basin of the pond until it
reached a level even with the lower
end of the stream (fig. 41, lower).

After the sluice boards had been
installed in the outlet to maintain
this height, the outlet valve was
opened and the overflow water al-
lowed to pass through. Finally,
the refuge zones were covered with
lids made of tarred paper and strips
of lath and netting was stretched
over the stream.

Anyone contemplating the propa-
gation of creek chubs need not con-
struct a raceway exactly duplicating

88

CREEK CHUB

either of the two just described.
When constructing a spawning
stream, it is important to take into
account the ecological conditions
affecting the breeding habits of the
creek chub, such as currents, pools,
hiding places, and types of bottom
soil. As life-history studies show"
that the creek chub prefers a certain
type of habitat (p. 86), it is desir-
able to provide these conditions as
completely as possible. Raceway
streams can be made any length de-
sired ; the width does not necessarily
have to be confined to 4 or 5 feet,
provided that a sufficient volume of
water is available to operate effec-
tively a wider channel. Most im-
portant is the water supply. The
water should be clear in color, have
a temperature range of 55° to 60°
F. during the spawning season, and
be free of other species of fish.

Stocking the raceway

Selecting the brood stock. — An
operator selecting brood stock must
bear in mind that the male chub
grows larger than the female; that
the mature male is distinguishable
from the female by the presence of
bony protuberances (horns) on the
head immediately before and dur-
ing the spawning season; and that
the male is usually highly colored
during the spring, having tinges
of red on the paired fins and abdo-
men. In contrast, the adult female
is generally smaller and more drab
in color and has a swollen abdomen
during the spawning season.

Results of Michigan studies in
the selection of brood stock indi-

cate that it is advisable to use 6-
to 8-inch males and 5- to 6-inch
females for breeders. If larger
males (7 to 10 inches in length) are
available and the total stock of
breeding males could be represented
by fish of this size, results should
prove satisfactory. Likewise, if
larger females (6 to 8 inches in
length) are available, they could
also be used.

It is not advisable to mix small
(5-inch) mature males with larger
(10-inch) males in the same race-
way, because mortality occurs as a
result of fighting. Where small (3-
inch) females are mixed with larger
(8-inch) females in the same race-
way, a prolonged spawning season
occurs, resulting in a loss of fry.
The larger females mature about 2
weeks earlier than the smaller ones,
and by the time the smaller females
are through spawning, many fry
have hatched and emerged from the
earlier-formed nests. The presence
of fry in the raceway and base pond
before the brood stock is removed
naturally complicates removal of
the fry.

One more suggestion concerns the
age of adult fish. Normally, only
a few pond-reared creek chubs can
be expected to mature in their first
year and be used as breeders. In
the second year, possibly 50 percent
will mature (depending on the rate
of growth, the larger fish being the
more favored) ; as a result, most of
the brood stock will have to be se-
lected from older fish. In natural
waters, female creek chubs nor-
mally do not mature until their

89

SOME IMPORTANT BAIT FISHES

fourth year and males their fifth.
Creek chubs are not long-lived fish,
rarely exceeding 6 or 7 years.

Stocking rates. — Recommended
stocking rates calculated on a the-
oretical basis derived from observa-
tions and studies conducted in
Michigan may not be entirely sat-
isfactory for all types of raceways.
It is believed, however, that a brood
stock should contain more females
than males (approaching a ratio of
2 to 1 or 3 to 2). Furthermore,
each female in stock composed of
3.5- to 7-inch fish should be pro-
vided with 1.5 square feet of spawn-
ing area for egg deposition, and
each female from a gi'oup composed
of 4- to 8-inch chubs, 2 square feet
of area. In calculating the square
feet of available spawning area in
a raceway, the margins along the
banks (about 3 inches on each side
of the stream) and any areas used
for refuge zones or current deflect-
ing structures should be omitted.
Generally, about one-fourth of the
total area will be taken up by these
structures.

To illustrate, let us suppose that
an operator had a raceway 200 feet
by 4 feet, and wished to determine
the number of breeders it would ac-
commodate. Assuming that one-
fourth of the total area would be
occupied by the banks, refuge zones,
and other structures, he would have
to make his calculations on the re-
maining 600 scjuare feet of stream-
bed. If 3- to 7-inch females were
used, about 400 of these and 200
males would be required if a sex
ratio of 2 to 1 were established, or

about 266 males if a 3 to 2 ratio were
followed. If 4- to 8-inch females
were used, 300 would be needed
with the corresponding ratio of
males. The mortality rate of adult
creek chubs during the spawning
season has been exceptionally high,
sometimes amounting to as much as
75 percent. To be assured that an
adequate supply of adult fish will
be available each spring, provision
should be made whereby a new
group of fish will be maturing each
year.

Results from creek-chub studies
in Michigan indicate that with a
fair amount of success in fish cul-
ture, about 800 fry may be expected
for every female creek chub intro-
duced in a spawning raceway. In
Ohio, each female introduced into
a spawning raceway in 1941 gave a
return of about 400 salable fish, and
in 1942 about 450. Since we have
some idea as to the spawning needs
of the female chub and can roughly
calculate the number of females
which will satisfactorily stock a
specified raceway, a crude estimate
can be made as to the number of
females and the size of the raceway
necessary to realize a predeter-
mined production.

There was considerable difference
in the size range of the fish pro-
duced in individual ponds. Ponds
that had a high production con-
tained smaller fish than those of low
production. In ponds where the
average length of the chubs was
about 2 inches, the number of fish
per pound was 300. In other ponds
where the fish averaged about 31/^

90

CREEK CHUB

inches in length, the number per
pound was reduced to 100 fish. In
some ponds where overstocking had
occurred, the minnows at the end of
the growing season had an Average
length of 11/2 inches. It was
learned that when these unsalable
fish were returned to growing
ponds the next year, it took several
weeks before growth was resumed.
It seems that these fish had been
stunted the previous year by the
crowded condition. From this ex-
perience it is suggested that an op-
erator should be careful and not
stock his ponds at the maximum
rate.

The following table presents the
number of creek chubs of various
lengths to the pound and gallon-

Length of fish
(inches)

Number

of fish per

pound

Number

of fish per

gallon '

1

1.5

2_-

1,360

915

360

170

92

57

36

24

17

12

10

10, 880
7,320
2, 880

2.5 - .

1,360

3 - _ - -

736

3.5

456

4

4.5

5

5.5

6

288

192

136

96

80

''■ 1 gaHon equals 8 pounds.

Spawning

Creek-chub breedere should be in-
troduced into the raceway when the
species is known to be spawning in
nearby natural waters. If a check
cannot be kept on natural spawn-
ing, or if no natural spawning oc-
curs in the area, it is advisable to in-

troduce the fish when the water
temperature in the raceway has
reached 55° F. for a 2- or 3-day
period. Creek chubs usually start
to spawn during the latter part of
April in waters north of an imagi-
nary line drawn east and west from
the Michigan-Ohio border. Spawn-
ing is terminated late in May or
early in June in the Lake Superior
area, but continues into July in
northern Minnesota. The nesting
season for any one locality usually
lasts about 3 weeks.

At one commercial hatchery, it
was noted that the breeder chubs
used the spawning raceway for
about a 3-week period. During the
first few^ days, the population of
breeders steadily increased until a
maximum number was present on
about the seventh day. At this time
about 4,000 breeders were occupy-
ing the raceways. Following this
peak, the number of breeders de-
creased daily until only about 100
were left at the end of the 3-w^eek
period. During the early part of
the spawning period, the male chubs
select areas in the raceways well iso-
lated from one another. Later,
however, there is considerable pi-
rating among the redds — the in-
creased population of breeders
bringing on additional competition
for space. It is estimated that at
least 50 percent of the redds are de-
stroyed in this manner during the
spawning season. Many dead chubs
of both sexes collect on the surface
of the brood pond within a week
after the onset of spawning activity.
By keeping a careful record of the

91

SOME IMPORTANT BAIT FISHES

number of breeders removed from
the pond each fall for the 4-year
period, it was calculated that at
least 30 percent of the males and 15
percent of the females die each year.

Stripping creek chubs

In regions where natural ponds
are used for minnow culture, creek-
chub raceways are not practical be-
cause of the lack of running water.
Fry for these ponds can be obtained
more easily by stripping the adults
of their eggs, fertilizing the eggs,
and hatching them in jars. Until
recently, ripe creek chubs were diffi-
cult to obtain and the green fish
would not ripen in the ponds that
were available.

Michigan workers (Ball and
Bacon, 1954) have been successful
in injecting creek chubs with carp
pituitary to ripen them. The fish
then are stripped of their eggs,
which are hatched in Meehan jars.

The pituitary Avas obtained from
6- to 8-pound carp by the following
procedure :

The head of the carp was removed, and
the brain was exposed by removal of the
dorsal surface of the brain case. The
broad white ophthalmic nerve, attached
to the fore of the brain, was picked up
with a pair of tweezers and the entire
brain lifted up and laid back. The pitu-
itary gland, a small organ resembling an
acorn, is located underneath the largest,
rounded portion of the brain. Occasion-
ally the gland will remain on the floor
of the brain case.

The glands were either imme<liately
frozen or dehydrated and defatted in cold
acetone for .'i6 hours. The acetone-
treated ^'l;inds were dried on filter paper

and stored under refrigeration until
needed.

Whole glands were used in all experi-
nients, no attempt to separate the lobes
being made. Just before use, dried
glands were i)ulverized in a mortar and
mixed with distilled water ; frozen
glands were macerated to form a thick
suspension in distilled water. No dif-
ference between the effects of frozen
and dried pituitaries on fish was noted
in any experiments.

Each ripe female received one-
fourth of a pituitary from a 2-
milliliter glass hypodermic syringe
supplied with a No. 19 needle. The
tip of the needle was placed under
a scale, pushed through the belly
wall into the body cavity, and di-
rected parallel to the ventral sur-
face. Two men were required for
the job : one to hold the fish ajid the
other to handle the needle. After
injection, the chubs were held in
tanks in which water varied from
46° to 64° F. At the end of 48
hours, the fish were stripped and
nearly all gave up their eggs. Fer-
tilization of the eggs by the usual
hatchery method produced nearly
a 100 -percent hatch.

Growing-pond operation

As soon as the fry concentrating
in the base pool become conspicuous
and are grouped in schools along
the shore, they can be collected with
a bobbinet seine and transferred to
rearing ponds. The removal of the
fry from the brood pond is a simple
task. The creek-chub fry tend to
school in large numbers near the
surface along the shore of the brood
pond. By using a small nylon hand

92

CREEK CHUB

seine, one operator can collect up
to 500,000 fry in a day. In collect-
ing the fry, the operator carries a
floating container tied to his wader
strap. In this manner, the small
fish are transferred from the hand
net to the container without injury.

As soon as a sufficient number of
fry is collected, the fish are trans-
ferred in cans to the growing ponds.
It is almost impossible to make an
accurate count of the number of
fry collected other than by hand
counting, which wovdd be an endless
job. About the only method for
estimating numbers of fish would be
to concentrate the fry in a container,
such as a tub, and remove them
with a quart dipper in which the
estimated number per dipper had
already been determined. Natu-
rally, there would be considerable
error involved.

Stocking the groicing ponds.- —
The stocking rate of chub fry in
growing ponds can be varied con-
siderably. In ponds where an op-
erator can supply an incoming
flow of about 150 gallons of spring
water a minute for each acre of
Avater, he can stock at the rate of
600,000 fry to an acre and obtain
a very satisfactory return. If the
incoming water supply is limited
to about 25 gallons a minute for
each acre of water, then it is de-
sirable to reduce the stocking rate
to about 300,000 fry to an acre of
water. In ponds that do not have
an incoming supply of water, the
operator should not stock heavier
than 50,000 fry to an acre of
water.

The records show that in the
transfer of fry from the brood
ponds to the growing ponds a high
survival can be expected. It also
seems, according to the informa-
tion available, that the rate of sur-
vival is in direct proportion to the
stocking rate. Ponds stocked at
the rate of 50,000 to 200,000 fry per
acre of water had about a 90-per-
cent survival; those stocked at the
rate of 250,000 to 400,000 gave a
return of about 80 percent sur-
vival; and those ponds in which a
nuiximum transfer was made gave
a return of about 60 percent.

Artificial feeding. — During the
first 6 weeks of life, development
of the chub fry is rapid in ponds
having a prevailing water tem-
perature of between 70° and 75°
F. In this period the fry readily
eat fine-grained artificial food. By
the end of the 6 weeks, most of
these small fish will have reached
a length of about 11/4 inches, and
there is a marked change in their
diet demands : they are no longer
interested in the fine food, but seek
larger food particles. The oper-
ator must now provide a pellet
type of food ranging in diameter
from i/i6 to i/g inch, or introduce
a small forage minnow, such as
fathead fry.

A considerable amount of study
has been conducted on diets for
the creek chub at commercial
hatcheries, and at present the
most satisfactory diet mixture con-
sists of 4 parts of gray shorts or
ground whole wheat, 3 parts of
meat scraps or some comparable

367913 O— 5e

93

SOME IMPORTANT BAIT FISHES

animal protein, 1 part of cotton
seed meal or soya-bean meal, 1
percent of brewers yeast or wood
yeast, and 1 percent of a mineral
supplement, such as that used in
livestock feeds. The small fish are
given this formula in a dry, pow-
dered form, and the larger fish are
provided with the same food pre-
pared in pellet form.

In feeding creek chubs, care must
be taken not to overfeed. The op-
erator should watch the plankton
turbidity of the water and be sure
that the bloom will not mask a
w^hite disk at a depth of 24 inches.
The food can be fed to the fish
once each day or, in reduced
amounts, several times a day.
Usually, an acre pond with a good
flow of spring water and a large
population of growing chubs will
require about 50 pounds of food
daily during the minnows' maxi-
mum growing season. At the end
of a growing season, a successful
operator should be able to realize
a food conversion whereby 2
pounds of food has produced 1
j)ound of salable minnows. In
heavily stocked ponds where the
average length of the minnows will
be smaller than those in lighter
stocked ponds, the conversion ratio
will be about 4 to 1.

Harvesting and storing the fish

The production of creek chubs
in pounds or in numbers of salable
fish per acre of water has consid-
erable variation. The records
from one commercial hatchery,
covering a 4'year period starting
in 1949, show that the annual pro-
duction of salable creek chubs per
acre of water varied from a low
of 500 pounds to a high of 3,000
pounds. It was found that when
only a portion of the fish are to
be removed and these are to be
removed by trap or seine, then it
is not too important whether the
water is cool or warm; but if the
pond is to be drained, it is very
desirable to lower the water tem-
perature to about 70° F. before
any fish removal attempts are
made.

When chubs are removed from
the growing pond to be placed in
storage vats for sale, they should
be held in water having a temper-
ature of 60° to 65° F. By using
cool water in the storage tanks, the
chubs can be kept for a 2- or 3-
week period without any ill effect.
Also, when chubs are in storage
for any extended period of time,
they should be fed the same type
of food daily that they received
in the growing pond.

GOLDEN SHINER Notemigonus crysoleucas

Also called Roach.

LIFE HISTORY

Description. — Body thin and flat
from side to side, deep from top to
bottom; adult golden in color.

scales loose and easily visible;
mouth small and upturned, with no
barbels; base of anal fin long, con-
taining many more than the cus-

94

GOLDEN SHINER

Length of fish

(inches)

Number

of fish per

pound

Number

of fish per

gallon *

1

1.5 - ---

4,250

1, 120

430

215

118

71

47

32

23

16

12

34. 000

8, 960

2

2.5

3

3.5

4

4.5

5

5.5

6

3,440
1, 720
944
568
376
256
184
128
96

tomary 7 or 8 rays; dorsal fin far
behind the pelvic fins; dorsal and
anal fins sharply pointed; sharp
ridge or keel on belly between pel-
vic and anal fins ; lateral line curves
downward and follows ventral body
contour.

The female grows faster and
larger than the male. This species
may mature in 1 year in warm re-
gions at a length of 21/2 inches, but
in most of the Lake States it prob-
ably does not mature before the , , „ , _ ,

•^ ' 1 gallon equals 8 pounds.

second year. Members of this spe-
cies are known to have lived for 8 Rangre.— The golden shiner is
years. A maximum length of 10 widely distributed throughout the
inches has been reported. eastern United States from Can-
The following tables present ada to Florida, and westward to
data on the rate of growth of the Dakotas and Texas. The west-
golden shiners in natural ponds, ern form, mratus, is most common
and the number of fish of various west of the Allegheny Mountains
sizes to the pound and gallon. and north of Arkansas and is the

only subspecies occurring in the
Lake States. This species prefers
lakes, but is also common in the
quiet sections of some of the larger
rivers, frequenting weedy bays and
shoals.

Breeding habits. — The golden
shiner has a long spawning season,

Number of
days

Length
of fish
(inches)

0.3
.6

.9
1.2

Number of
days

Length
of fish
(inches)

10

20

30

40

50

60

70

1. 5

1. 8

2. 1

95

SOME IMPORTANT BAIT FISHES

extending from the time the water
reaches 68° F. tlirough the rest of
tlie summer. The eggs, which are
adhesive and stick to plants, are
commonly scattered over filamen-
tous algae and less frequently over
rooted aquatic plants.

Food. — The golden shiner is
omnivorous. The young feed on
algae and entomostracans. The
adults have been known to eat young
fishes, insects, plankton, crusta-
ceans, protozoans, algae, diatoms,
and mollusks. Some stomachs con-
tain nothing but insects; some,
nothing but plankton; others, 95
percent algae ; a few had more than
75 percent amphipods; and three
contained 5 percent arachnids. The
food percentages in golden-shiner
stomachs examined by a number of
workers are as follows : Insects, 35 ;
plankton, 28.5; algae, 13.8; plants,
5.3; amphipods, 0.4; mollusks, 1.9;
arachnids, 1.4; bryozoans, 1.4;
rotifers and protozoans, 0.2; and
crustaceans, 12.

Importance. — In Minnesota, this
shiner reaches a size for pike bait
in the fall of its first year. In
Michigan and Iowa, it has been pro-
duced at a rate of more than 200,000
a water acre in fertilized ponds.

The golden shiner is a popular
m i n n o w with fishermen every-
where. Tlie light color and general
activity make it a good minnow to
use for wa.lleyes. The greatest de-
mand for this minnow comes in the
winter time when the Avater is cold.
In warm weather, the golclen shiner
is very delicate and is hard to keep
alive in the bait ])ail so the fisher-

man uses suckers for summer pike
fishing.

PRODUCTION

The propagation of the golden
shiner is conducted in extensive
and intensive artificial ponds and
extensive natural ponds. Intensive
ponds are operated on the principle
that greater production can be ob-
tained if the brood fish are main-
tained in a pond with ideal
spawning conditions and the fry
are transferred to growing ponds as
soon as they are free swimming.
In an extensive hatchery, the fry
remain in the same pond with the
brood fish until harvest time.

An intensive golden-shiner hatch-
ery should be made up of units that
contain one large pond for spawn-
ing and three smaller growing
ponds. When the ponds are sup-
plied with spring water, the grow-
ing ponds do not have to be adjacent
to the brood pond. If the ponds
are maintained by surface runoff,
the growing ponds sliould be located
so the water from the brood pond
can be used in the growing ponds.

The brood pond used in intensive
operations should be free of vege-
tation so that the fry can be re-
moved without difficulty. An ex-
tensive production })on(l should
contain enough vegetation to i)ro-
tect the fry from the cannibalistic
adults.

In the Northern States where
pond construction is expensive,
golden shiners are raised in natural
l^onds (fig. 42). Usually they are

96

GOLDEN SHINER

raised in ponds that are too fertile
for suckers, because the golden
shiner can stand more adverse con-
ditions. It is also desirable because
most of the fertile ponds contain
masses of filamentous algae which
provide plenty of places where the
shiners can deposit their eggs. The
best natural pond for the propaga-
tion of golden shiners is 2 to 3 acres
in size and 4 to 5 feet deep. The
pond must be free of fatheads or
the spawning success of the shiners
will be poor.

Stocking the ponds

Golden-shiner breeders should be
at least 1 -year-old fish, ranging in
size from 31^ to 8 inches in length.
About 50 percent of the brood stock
should be less than 5i/^ inches in
length ; or otherwise, the total stock
wnll be predominantly females,
since the males are consistently the
smaller. The stocking rate in large
ponds, where the fry will remain
with the adults (extensive culture)
should range from 2,000 to 3,000 fish

ItJk.

Figure 42. — A productive golden-shiner pond in Minnesota.

97

SOME IMPORTANT BAIT FISHES

for each surface acre of water. In
ponds where fry removal is planned
(intensive culture), the stockinfr
rate of breeders should be 4,000 to
8,000 adults per surface acre of
water. In Minnesota n a t u r a 1
ponds, the stocking of 500 adults to
the acre has proved satisfactory.

Spawning

In Missouri, the golden shiner
starts spawning activity when the
temperature of the pond water rises
above 70° F. If the temperature
exceeds 80° F., spawning ceases.
In this State, the spawning activity
of the golden shiner starts during
the latter part of April or the fore-
part of May, and usually terminates
in early June. During this period,
at least 4 or 5 distinct spawning
cycles have been observed. The
cycles are separated by periods of
about 4 or 5 days. During the
summer months w^hen the water
temperature in the brood ponds ex-
ceeds 80° F., there is no spa.wning
activity unless a cool rain reduces
the water temperature sufficiently
to shock the fish into further spawn-
ing activity.

The spawning act usually starts
early in the morning and terminates
before noon. The females deposit
their eggs on any type of sub-
merged debris. With a water tem-
perature ranging between 75° and
80° F., the fertilized eggs will hatch
within 4 days after deposit.

A few days after the eggs are
fertilized very small fry can be ob-
served swimming in schools near
the surface along the shore margin

of the pond. At this stage of de-
velopment, an operator can collect
these small fish with a fine-mesh
net and transfer them to the grow-
ing ponds. By transferring the fry
to other ponds, he can realize about
twice the production of those ponds
where the adults and fry are left to-
gether. The reason for this in-
creased production is due to the
fact that the adults prey on the
smaller fish throughout the season,
thus reducing the total population.
If the minnow producer decides to
transfer the golden-shiner fry to
growing ponds, the recommended
rate is from 200,000 to 800,000 for
each acre of water. Undeo" this
progi'am, a successful propagator
can realize a production of 75,000
to 150,000 salable fish per acre of
water. In ponds w here the fry re-
main with the adults, 60,000 salable
minnows for each acre of water is
considered good production.

Artificial feeding

Golden-shiner production ponds
that contain only small fish intro-
duced at the prescribed stocking
rate (see above) can be fed daily a
diet of 8 parts of gray shorts, 1 part
of cottonseed meal, and 1 part of
tankage or meat scraps. In ponds
where there is no incoming fresh
water, the daily feeding, regardless
of the number of fish within the
pond, should not exceed 10 pounds
of food for each acre of water. At
this rate, the operator should not
feed more than 4 days each week.
In ponds supplied with an incoming
flow of fresh water, a daily food

98

GOLDEN SHINER

quota of up to 25 pounds to an acre
of water can be supplied. In all
instances, regardless of the feeding,
the plankton turbidity of the water
should not be allowed to become
dense enough to obscure a white ob-
ject at a depth of less than 12 inches.

Harvesting and storing the fish

The harvesting of the golden
shiner in Missouri and surrounding
States is an exacting task, otherwise
severe injury will result in a high
mortality. When golden shiners
are to be seined from a pond during
warm weather, the seine should be
made of either a cotton netting or
bobbinet m a t e r i a 1. The fish
trapped in the seine should not be
rolled or crowded while bringing
them in near shore. When the
golden shiner is removed from the
seine by a hand net made of a soft
fabric, the fish should be trans-
ferred with a considerable amount
of water.

When the entire population is to
be removed by draining the pond, it
is necessary to lower the tempera-
ture of the pond water to about 75°
F. before undertaking the task. If
the pond is such that the water can-
not be cooled to this degree, the op-
erator should wait until weather
conditions are favorable for the re-
moval. In the reservoir type of
culture, many operators have to
wait until fall.

In Minnesota, natural shiner
ponds should be harvested in the
fall when the weather is cool. The
fish will .be of pike-bait size then
and hardy enough to stand han-

dling. While it is possible to han-
dle golden shiners in summer with
special nets, the fish are too delicate
for the fisherman to carry in the
minnow pail. Most of the fish
seined in the fall will have to be
held in large tanks or holding
ponds supplied with running water
until they are needed for winter
fishing.

Production in g o 1 d e n-shiner
ponds varies more than that in
sucker ponds because shiner pro-
duction not only is dependent on
the rate of stocking and the amount
of food available, but is primarily
determined by spawning conditions
and spawning success. A pond
with poor spawning conditions will
produce a small crop of fish, while
a pond with good spawning condi-
tions will produce a large crop. Of
course, the fish from the last two or
three spawnings will not grow
large enough to be used the first
year, but most of the others will be
suitable for winter fishing the first
winter. Optimum production in
natural ponds probably can be ob-
tained by removing the adults
from the pond after the fourth or
fifth spawning. The production of
eight Minnesota golden-shiner
ponds averaged 145 pomids an acre,
and the maximum was 390 pounds
an acre. AVhen the production was
over 300 pounds to the acre, about
5 percent of the fish were pike-bait
size minnows. When the produc-
tion was around 150 pounds, 70 per-
cent of the fish were pike-bait size.

When golden shiners are re-
moved from the ponds to the stor-

99

SOME IMPORTANT BAIT FISHES

age vats, the storage water should
not exceed 70° F. During the first
24 hours of storage, the fish are
highly excitable and react violently
to any sudden jar or fast-moving
object. It is well for the operator
to take these factors into considera-

tion and to approach the storage
tanks quietly when attempting to
handle the fish. If he plans to con-
fine the salable golden shiners for
a 2- or 3-week period in holding
tanks, it is desirable to maintain a
water temperature of about 60° F.

GOLDFISH Carassius auratus

Also called Indiana, Baltimore, and Missouri Minnow.

LIFE HISTORY

Description}. — Mouth small but
not sucker shaped; no teeth in the
jaws; dorsal fin with more than 10
rays; a smooth spine at the leading
edge of the dorsal and anal fins;
scales large; no scales on the head,
cheeks, or gill covers. The male de-
velops tiny tubercles on the sides of
the head and front edges of the pec-
toral fins during the mating season.
In natural waters, goldfish grow to
a weight of 3 to 5 pounds.

Range and hreeding habits. — The
goldfish was originally imported
from Eurasia as an ornamental
aquai-ium lisli, but has since been
introduced into ii:itui'al waters by

well-meaning persons who tired of
their care.

Goldfish normally start spawn-
ing when the water reaches 60° F.,
and continue to spawn throughout
the summer if the temperature re-
mains above 60° and the fish are
not overcrowded. The favorite
spawning time is right after sun-
I'ise on sunny days. The female
lays the eggs on grass, roots, leaves,
or similar objects. The eggs are
adhesive and stick to any object
they touch. The male fertilizes the
eggs innnediately. The eggs are
clear when laid and turn brown as
t hey develop. Dead eggs are cloudy
and opaque. The eggs hatch in 6
to 7 (lavs in water of 60° ^. A fe-

100

GOLDFISH

male goldfish may lay 2,000 to 4,000
eggs at one time and may spawn
several times during the season.

Food. — Goldfish feed largely on
plankton, but will take insects and
very small fish.

Importance. — Many States pro-
hibit the use of goldfish for bait
because of the danger of intro-
ducing them into valuable game-
fish waters. Experience in some of
these States has shown the goldfish
to be as vigorous as carp in destroy
ing game-fish habitats.

The goldfish is a good bait fish
to raise in the States where it is
legal. It is hardy and lives well
in crowded pails even during hot
weather. It reproduces in large
numbers and grows rapidly. Gold-
fish of various sizes can be used as
bait for most of the fish-eating game
fish.

PRODUCTION

In the southeastern United
States, where the goldfish is legal
bait, it is perhaps the best bait fish
to raise. Even in the South, a
hatchery operator who plans to
propagate goldfish for bait should
check the State laws that regulate
minnow use and transportation.

The best type of pond for gold-
fish is less than I/2 acre in size and
4 or 5 feet deep. Small ponds can
be harvested before the water be-
comes too warm and the oxygen
supply becomes too low for the fish.
Production ponds should be filled
early in March and fertilized at the
rate of 200 pounds of 8-8-6 ferti-
lizer per acre. Similar applications

sliould be repeated at 2- or 3- week
intervals until the pond is drained.

Stocking the pond

Medium-sized, uncolored goldfish
should be used for brood stock, be-
cause fish of that size reproduce well
and fish of that color are preferred
for bait. Brood stock that is over-
wintered in crow^ded ponds will not
spawn in the holding ponds. Maxi-
mum egg production is obtained by
keeping the brood fish in the over-
wintering pond until after the last
spring frost. Then the fish can be
put in the production ponds with-
out danger of frost damage to eggs
or fry.

The production ponds should be
stocked with 200 to 300 adults per
water acre. As the males can be rec-
ognized by their tubercles, it is pos-
sible to stock equal numbers of
males and females.

Spawning

Spawning is encouraged by plac-
ing a row of spawning mats near
(he shore of the pond. Spawning
mats are wire-bottom frames filled
with moss, excelsior, or grass, that
fioat on the surface of the pond.
The fish lay their eggs on the bot-
tom side. When the mats are
moved to clean ponds to hatch
the eggs, the sides of the spawning
pond should be covered with boards
so the fish cannot spawn on the
grass. If the eggs are allowed to
hatch in the ponds where they are
laid, the adults will stop spawning
when the pond becomes crowded

101

SOME IMPORTANT BAIT FISHES

with yoiin^ fish. When the eggs
aie moved to clean ponds to hatch,
the uncrowded adults will spawn all
summer.

Artificial feeding

Goldfish pioduction can be in-
creased in most ponds by supple-
menting the natural food produced
by fertilizing with artificial food.
Soybean meal, peanut meal, poul-
try mash, and cottonseed meal are
good supplementary foods for
goldfish. The food should be fed
at the same time each day and
should be thrown into shallow
water in the same place each day
so the fish become familiar with
the routine. The fish should be

fed all of the food they can con-
sume in 2 hours.

Harvesting the fish

Goldfish production will vary
according to the size and condition
of the brood stock, number of dis-
ease organisms affecting the adults
and the young, amount and kind
of fertilization, and the quantity
and kind of su])plementary feed-
ing. In general, ponds containing
both young and adults will pro-
duce up to 100,000 fingerlings to
the acre. Intensive hatcheries
where a heavily stocked brood
pond provides fry for 8 or 10
growing ponds, the production will
reach 200,000 to 300,000 bait fish
to the acre.

PEARL DACE Margariscus margarita

Also called Leatherback Minnow,

LIFE HISTORY

Description. — Robust minnow ;
snout blunt and head rounded;
small but visible scales; mouth not
extended behind eye; color a dusky
silver mottled by darker scales; no
large nui)tial tubercles, no black
pigment si)ots on Hus. The i)earl
dace grows to a length erf at least
^1^ inches in 1 year, and reaches
;i maxiinuni of 7 inches.

Range. — The pearl dace prefers
cool lakes, bogs, and creeks. Its
I'ange is through all Canada east
of the Kockies and the northern
I'nited States to New York.

Hireding hahff.s.—]h: T. H.
Laiiglois (V.yii)) reports that—

tlu' Xortheni Dace were .seen spawning
in a dear water stream of 1 V^ to 2
feet deptli and !."» feet widtli, in or out
of the current, on sand or gravel bot-
tom, witli the water temperature from

102

HORNYHEAD CHUB

63° to 65° F. * * * Each adult male
maintains a small area of the stream
bottom as his private spawning ground,
guarding it against intrusion by other
males, and apparently restricting his
own spawning to it the major share
of the time. * * * his brief perio'ds at
home are spent nosing over the bottom as
if seeking eggs to eat. The moment an-
other dace reaches his vision he is .off in
pursuit, but seldom ranges farther than
4 feet from his home. If the stranger
proves to be a male he is promptly es-
corted away * * * *

If the stranger should be a female,
and if she permits the male to drive her
into his holding instead of fleeing, and
if, once there, she stays and permits
the male to pair with her, the process
occurs in this manner. The two flsh
come to a position side by side, close
to bottom, and, if there is a current,
heading upstream. The oversized tu-
bercle-roughened pectoral fin of the
male is slipped beneath the anterior
part of the body of the female, and his
tail is crossed over her back, just be-
hind her dorsal fin. * * * When this
position has been reached both fishes
vibrate the posterior parts of their bod-

ies rapidly * * * and * ♦ * the eggs
and milt are * * * extruded * ♦ *
since each female repeats the act many
times during the breeding season she
must extrude but a few eggs each time.

Food. — The food habits of the
pearl dace have received little at-
tention. From the studies avail-
able, it seems probable that insects
are preferred, but the fish has been
known to feed on phytoplankton,
mollusks, surface drift, and water
mites.

Importance. — It is possible that
the pearl dace can be reared suc-
cessfully in artificial ponds, and
that bait sufficiently large for
catching panfish could be raised
in one season. Because it makes a
fine growth in northern boggy
waters, this fish could be raised in
northern areas in places where
land is cheap. For dealers with
little working capital, this species
seems to oifer excellent opportuni-
ties.

HORNYHEAD CHUB Nocomis b/guffafus

Also called Redtail Chub.

LIFE HISTORY

Description. — Heavy, robust
minnow; blunt nose; large scales
clearly outlined ; large diffuse black
spot at base of tail, tail fin red in

young (accounting for some call-
ing it the redtail chub) ; small
barbels at corners of mouth; body
color usually olivaceoiis; large
tubercles on top of head and orange-

103

SOME IMPORTANT BAIT FISHES

red spot behind eye of breeding
males.

Range. — The hornyhead chub is
a minnow of hirge creeks and small
rivers, preferring swift waters and
gravel bottoms. It is found in the
United States from North Dakota
and Colorado east to the Great
Lakes and the Hudson River, and
south to Oklahoma and the Ohio
River valley.

Breeding habits. — This chub
spawns late in May and early in
June on gravelly riffles in 1 to 2 feet
of water at 65° F. or warmer. The
nest is either a natural cavity in the
stream bottom or one fanned out by
the fish. Mating activities and
stone carrying into the nest by
males are alternated so that the peb-
bles and eggs are mixed in the nest.
The nest pile is large, often cover-
ing several square feet of bottom,
and 2 to 6 inches deep. Each nest
is occupied by a single male who

probably spawns with several fe-
males. These nest piles are often
used by common shiners at the same
time, the males of both species
guarding the nest. The male at-
tains a maximum length of about
10 inches and the females are smal-
ler. This minnow requires several
years to reach maturity.

Food. — The food of the horny-
head chub is mostly insect larvae
and crustaceans. A summary of
several food studies made in New
York showed an average percentage
of the following food items : Cray-
fish, 5.6 ; mayflies, 11.1 ; caddisflies,
2.8; chironomid larvae and pupae,
29.4; miscellaneous insects, 7.8;
small beetles, 23.9 ; algae, 13,9 ; and
silt, 5.6.

Iniportance. — The hornyhead is
an excellent bait fish for pike, hardy
on the hook or in storage tanks,
and attains large size.

RIVER CHUB Hybop/s (Nozomis) m/cropogon

LIFE HISTORY of young sometimes amber but not

Description.— hody robust, nose '"^^^ ' "" ''^'^ «P"^ ^^ehind eye ; several

blunt, scales large and easily seen, ''^I'Se tubercles on swollen forehead

similar to liornyhead chul), p. 103; oi breeding mules. It difl'ers from

black spot at base of tail iiulistinct thelioinyliead chub in having an in-

and of no definite shape; tail fin distinct black spot of no definite

104

BLACKNOSE DACE

shape at the base of the tail, no red
on the caudal fin, and in its prefer-
ence for larger rivers.

Range. — The river chub is found
in the eastern United States from
New York to Virginia and in the
Tennessee River drainage in
Georgia and Alabama, and north-
ward to southern Michigan.

Breeding habits. — The life his-
tory of the river chub is similar to
that of the hornyhead chub. Ex-
cellent descriptions of the breeding
habits of this chub have been writ-
ten by Michigan investigators. Ac-
cording to their observations, the
male first digs a pit 12 to 15 inches
in diameter and 3 to 6 inches deep
in the streambed in water less than
2 feet deep. Stones are removed by
being carried away in the mouth.
The male then fills the pit again
with other stones until a heap of
large pebbles, 30 inches across and

3 inches high, is accumulated — all
in 2 to 5 days. Small spawning
troughs are then made by the male
in the surface of this stone pile to
receive eggs and milt as they drop
from the spawning fish above. The
troughs are filled again with peb-
bles immediately after spawning.
Common sliiners, hornyhead chubs,
and stonerollers may use the stone
pile for a spawning place at the
same time.

Food. — The feeding habits of the
river chub are probably very simi-
lar to those of the hornyhead chub.
The two species were thought to be
the same for many years and very
little work has been done on them
separately.

Importance. — The river chub is
[)robably as important a bait fish
as the hornyhead chub, and most
dealers do not distinguish between
them.

BLACKNOSE DACE Rh/nichf/iys atratulus

Also called Slicker.

m^,m

LIFE HISTORY

Description. — A c t i v e , stream-
lined minnow, usually under 3
inches in length; color dusky or
black above with pronounced freck-
les or dark spots over top and sides

of body; black streak on side of
body, extending forward through
eye and snout; scales small but
easily seen; small barbel clearly
visible at each corner of moutli espe-
cially when the mouth is opened;

105

SOME IMPORTANT BAIT FISHES

fins short and rounded; dorsal set
behind pelvics.

Rcmge. — This (hice is found in
clear, rocky streams from Virginia
northward to the St. Lawrence
River, westward through the Ohio
River system and Great Lakes'
basin, to Nebraska, Iowa, and
North Dakota. It is most abundant
in small, cool streams, and is rarely
taken from lakes or ponds.

Breeding hahit^. — The blacknose
dace spawns in April and May
when the water temperature of the
creek reaches about 75° F. The
spawning site is located at the head
of riffles. It frequently occupies the
same riffles used by creek chubs —
when the chubs are absent. Lang-
lois (1941a) comments on the
spawning activities:

Each male oct-upies a "holding" thouf^h
shifting around considerably. When a
female enters a "holding:," the male goes
to her and sometimes passes several
times around her before coining to a
lateral parallel position for spawning.
When side by side, the female vibrates
her tail, sometimes nearly burying it
while doing so, and at the same time the
male's tail starts vibrating and curling

up over the female's tail to her dorsal
fin, when vibrations cease. Occasionally
the pair remains in place and spawns
again immediately, but usually they sep-
arate, the male darting forward while
the female relaxes limply onto one side,
remaining there sometimes for several
seconds.

The milt and eggs may be
stripped from ri})e males and fe-
males, and artificial fertilization is
practical. The eggs are about i/^g
inch in diameter when spawned,
but quickly swell to about y^ of an
inch.

Food. — The food of the black-
nose dace varies according to what
is available. Some workers have
found the diet to be 100 percent
insects while others have found it
to be at least '24 percent filamentous
algae. Crustaceans, diatoms, and
Avater mites are eaten when avail-
able in large enough numbers.

I ni portanee. — The blacknose dace
is a fairly important bait fish in
Minnesota where it is sold along
with the longnose dace under the
name of slicker. It is a hardy min-
now that can be used in pike, bass,
and catfish fishing.

LONGNOSE DACE Rhini'chfhys cafaracrae

106

LONGNOSE DACE

LIFE HISTORY

Description. — The lonfjiiose dace
lias an elongate and cylindrical
body. The color is olive <;reen to
brown above, with dark blotches on
the sides, an indistinct lateral band,
and pale beneath. The upper jaw
extends considerably beyond the
lower one. In this fish, the air
bladder is rudimentary or not fully
developed.

While the lontifnose dace reaches
5 inches, the <i:rowth is very slow.
Studies in Minnesota indicate the
longnose is 1.9 inches at the end of
the first year, 2.4 at the end of the
second, 2.9 at the end of the third,
^>.4 at the end of the fourth, and
0.9 inches at the end of the fifth
year. The fish for this study were
collected in southern Minnesota
trout streams.

Ranije and hreeding habits. —
This species ranges from coast to
coast in northern North America,
and southward in the interior to
Iowa, and along the mountains to
North Carolina, and also to north-

ern Mexico. It is found in small
to moderate-sized streams, and is
scarce or lacking in lakes. Usually
found with the blacknose dace, its
habitat preferences may be consid-
ered similar to that species.

The longnose dace breeds in
A])ril and May over sand or gravel
bottom in clean, swift streams.
During this period the males have
considerable red on head, sides,
and fins.

Food. — The food of 186 long-
nose dace from Minnesota trout
streams was chironomid fiy larvae
and i)upae, 48 percent; simuliid
larvae and ])upae, 23.2 percent;
ephemerid nymphs, miscellaneous
iiisects. 0.2 percent ; annelid worms,
1 percent; algae, 0.8 percent; and
debris, 5.8 percent.

Importance. — Like the blacknose
dace, the longnose dace is used by
anglers for bass and catfish bait.
This minnow has been propagated
at least once in Minnesota and
seems to do well in long, narrow
ponds supplied with a very small
amount of running water.

FINESCALE DACE 9U\\\e neogaea

Also called Rainbow Chub.

107

SOME IMPORTANT BAIT FISHES

LIFE HISTORY

Description. — R o b u s t minnow
growing- to 5 inches in len,<rth ; nose
blunt, fins short and rounded;
large terminal mouth, no barbels;
very fine scales; color dark: one
indistinct, black lateral band on
side of body ; inner lining; of body
cavity black; intestine less than
twice as long as body. It reaches
a size of 6 inches. Like the pearl
dace, its bright-red sides retain
their brilliance most of the year
but are most beautiful in late
winter.

Range. — This species is most
often found in cool, boggy creeks
and ponds. Its range includes
eastern Canada, the upper Missis-

sippi Valley, and northern parts
of noi'theastern Xnited States.

Food. — The limited food studies
conducted indicate that both phyto-
plankton and higher plants are
preferred. In some stomachs,
however, nearly half of the food
has been insects, and the minnow
is known to eat zooplankton and
crustaceans to a limited extent.

Importance. — The finescale dace
is tenacious of life and survives
well in crowded containers. It is
satisfactory ])ike bait. Though
little is known of its spawning
habits or requirements, it is possi-
ble that this species could be
grown successfully in small boggy
ponds.

NORTHERN REDBELLY DACE Chrosomus eos

Also called Yellowbelly Dace and Leatherback.

LIFE HISTORY

Description. — S m a 1 1 minnows
averaging H inches in length; two
dusky lateral bands from head to
tail ; dark bronze color except for
silvery belly of females, scarlet in
males; mouth small and pointing
uj)ward at end of snout; lining of
body cavity black, intestine more
than twice as long as body. The
scales are minute, and this species

has been called "'leatherback" by
sportsmen and minnow dealers.

Range. — Though their ranges
slightly overlap, the bait dealer
can best distinguish the northern
and southern forms of the redbelly
dace by the location of their cap-
ture. The northern form is found
connnoidy in bog ponds and slug-
gisli creeks from British Columbia
east to Nova Scotia, southward to

108

REDBELLY DACE

southern Michigan, southern Wis-
consin, southern Minnesota, the
Dakotas, Montana, and Colorado;
and in portions of northeastern
United States to Potomac River
drainages of Maryland. In Min-
nesota, it seems to j)refer acid bog
lakes; in Michigan, in addition to
its occurrence in bog lakes, it has
been found in small ponds show-
ing a heavy growth of chara and
a rapid deposition of marl.

Breeding habits. — In the spawn-
ing season, the males are brilliantly
colored. The abdomen is a beauti-
ful red, and the fins are highly col-
ored with red and yellow.

The spawning habits, rate of
growth, and age at maturity have
been carefully studied in Michigan.
The eggs are deposited entirely
upon filamentous algae. One fe-
male lays from 5 to 30 nonadhesive
eggs scattered through and entan-
gled among the filaments. The fe-
male darts from one algal mass to
another, laying eggs in each new
mass. The eggs hatch in 8 to 10
days at water temperatures of 70°
to 80° F. Spawning takes place
from the latter part of May into
August in southern Michigan.

Adult females, when dissected.

revealed the simultaneous matura-
tion of several hundred eggs and
the presence of at least two size
groups of maturing eggs. This
suggests that one female has no
fewer than two distinct spawning
periods during a season. The
young, hatching early in the sum-
mer, attain nearly adult size by the
end of the first growing season and
spawn early the next summer.
Those hatching late in the season
pass the first wnnter as small fish
and require most of the next sum-
mer to reach maturity, often not
spawning until their third summer.

Food. — Studies made in the St.
Lawrence watershed of New York
indicate that the northern redbelly
dace is mainly herbivorous, that it
feeds almost entirely on diatoms
and other algae, the remains of seed
plants, and only to a limited degree
on insects and animal plankton.

I rrvportanc e. — Experimental
propagation of this species in Mich-
igan has shown that 128,000 fish can
be raised per acre of water surface.
The redbelly dace is best suited to
cool waters. This species does not
reach a length of more than 21/^
inches and is valuable only as bait
for panfish.

SOUTHERN REDBELLY DACE Chrosomus eryfhrogasfer
LIFE HISTORY

Description. — The southern red-
belly dace differs from the northern
form in its more horizontal mouth,
longer snout, and narrower caudal
peduncle.

Range and hreeding habits. — The

southern redbelly dace is more
southern in range than its northern
relative, and has a decided prefer-
ence for cool, gravelly creeks from
Iowa, southern Minnesota through
southeastern Michigan eastward to
Ohio River drainages of Pennsyl-
vania and West Virginia, and south-

.S67913 O — 56-

109

SOME IMPORTANT BAIT FISHES

ward in the Mississippi River valley
to the Tennessee River system in
Tennessee and northern Alabama,
tlie northern Ozarks in Arkansas
and Oklahoma, and the Missouri
River drainage in Kansas.

The feeding and spawning habits
of this form are believed similar to
those of the northern species. The

major differences seem to be a pref-
erence by this species for spawning
on gravelly bottoms and sele^-tion
of a more insectivorous diet.

Importance. — In Minnesota, this
dace is not as hardy as the northern
species, but is frequently used as
bait for crappies in the southern
part of the State.

EMERALD SHINK Nofroph oHierino/des

LIFE HISTORY

Description. — B o d y thin and
streamlined, snout blunt; scales sil-
very colored, with no black pig-
ment, loose and easily removed;
mouth large with thin black lips
running to tip of nose; dorsal fin
behind point of pelvic-fin attach-
ment; anal fin pointed (as is dor-
sal) and containing about 9 rays.

Range and breeding habits. — The
lake emerald shiner is found in
large lakes and rivers, usually in
large schools in open waters. Its
lange includes the larger glacial
lakes in Hudson Bay, the Great
Lakes drainages, and the larger
tributaries of the Mississippi River.

The emerald shiner spa\yns over
gravel shoals from the middle of
May to early June. The fish aver-
age 1% inches at the end of the first

year and 3 inches at the end of the
second.

Food. — The food of the emerald
shiner consists largely of insects,
most of which are terrestrial. This
shiner has been known to feed on
entomostracans, algae, small fish,
fish eggs, terrestrial insects, aquatic
insects, and oligochaete worms.
The studies of several workei^s with
the lake emerald shiner show that,
in general, the food percentages are
as follows: Water fleas, 26.8; algae,
7.}); water boatmen, 1.0; nuiyflies,
l.;^>; caddisflies, 2.1; chironomids,
0.7; terrestrial insects, 7.9; miscel-
laneous insects, 26.3; fish eggs, 2.9;
crustacean debris, 10.7 ; and miscel-
laneous, 3.2.

Importance. — The emerald shiner
is often used for bait despite the
fact that it dies quickly and its

110

COMMON SHINER

scales come oft' easily. It is a jrood pike. Hardy in cold weather, this
bait for bass, perch, and walleye fish is a favorite for winter fishing.

COMMON SHINER Notropls corn uf us

Also called Skipjack.

LIFE HISTORY

Description. — Color silvery on
sides, white on belly when alive;
scales large, high, and narrow on
side of the body ; no barbel ; dorsal
fin inserted directly over pel vies; a
size of 8 inches, or more, attained
by males.

Range. — This minnow is common
in nearly all cool creeks and lakes
of northeastern United States. It
occurs from southern Canada along
the Atlantic coast to Virginia ; cen-
trally, southward to northern Ala-
bama, and westward from Ozark
region of Missouri to Arkansas
River system in Arkansas and
Oklahoma.

Breeding habits. — B r e e d i n g
males have large tubercles over the
top of the head, and body and fins
are brightly colored orange and
pink. It spawns on stream riffles
over gravelly bottoms, but its
abundance in some inland lakes
may mean that it is successful in

spawning on gravel shoals in quiet
waters. The spawning season is
short in Michigan, extending from
the latter part of May into June;
it begins somewhat earlier in Min-
nesota's western w^aters. Studies
in Michigan have shown that the
common shiner grows about 2 inches
the first year and requires 2 or 3
years to reach maturity.

Little or no success has been ob-
tained in stripping the eggs from
this fish. To raise this species,
rearing ponds should be arranged
to allow adult fish to swim up-
stream from the ponds to lay their
eggs. The young will then drift
downstream and grow in the ponds,
as do other species.

Food. — Only in the most recent
food studies have the subspecies of
this minnow^ been considered sepa-
rately. Here, the food habits of
the northern {frontalis) and the
southern (chrysocephalus) are con-
sidered together.

111

SOME IMPORTANT BAIT FISHES

The common shiner is omnivor-
ous in its feeding habits. It has
been known to eat algae, insects,
fish, phxnts, entomostracans, hy-
drachnids, protozoans, and des-
mids. Stomachs of this species
have contained in some instances
100 percent insects; in other, 100
percent algae and other plants.

The studies of several workers show
that, in general, the food percent-
ages are as follows: Insects, 37.2;
algae and other plants, 39.9 ; plank-
ton, 11.8; fish, 7.1; sand and silt,
1.1; and miscellaneous foods, 2.9.

Importance. — It is used widely
as bait for bass and pike, but is
one of the less-hardy bait fishes.

SPOTFIN SHINER Nofrop/s spifopferus

Also called Blue Minnow.

LIFE HISTORY

Description. — Body thin from
side to side, deep from top to bot-
tom ; dorsal fin with black pigment
on one or two membranes between
posterior rays ; breeding males often
steel blue wdth orange fins and
small, pointed tubercles on snout;
females and young fish silvery blue
in color.

Range. — The spotfin shiner pre-
fers rapid-running streams, but is
sometimes found in clear, weedy
lakes. It occurs from the eastern
part of the Dakotas to New Eng-
land, except in Lake Superior and
its tributaries, and south in the cen-
tral Mississippi basin to the Ten-
nessee River drainage of Alabama,
and to central Missouri.

Breeding habits. — The spotfin
shiner spawns from May to August
on gravelly riffles or over sandy
shoals. The adhesive eggs are
often laid on logs and dock pilings,
in crevices of submerged tree
trunks, and even in old pails.

Food. — The food of this shiner
consists mostly of insects. It has
been knowni to eat both aquatic and
terrestrial insects, small fishes, vege-
table matter, small crustaceans,
plankton, and carp eggs. Food
studies by several workers show
that in general, the food percent-
ages are as follows: Midge larvae,
17.5; mayfly nymphs, 6.2; insects,
64.7; and miscellaneous, 11.5.

Importance. — The spotfin is a
good bait species for crappies and
pike; it is active, and is hardy on
the hook and in the live box.

112

BRASSY MINNOW

BRASSY MINNOW Hybognathus hankinsoni

Also called Grass Minnow.

LIFE HISTORY

Description. — Small minnow
with large, easily removed scales;
scales not small and crowded be-
liind head ; brassy sheen on sides of
body; snout blunt and rounded,
mouth small; fins short, rounded
on tip and free edges; lining of
body cavity black, intestine (coiled
like a watch spring) more than
twice as long as body.

Range. — One of the most com-
mon and widespread bait fishes of
the Great Lakes region, except
Lake Erie in Ohio; ranges from
Montana to southern Ontario, and
the Lake Champlain region, south-
ward to Missouri, Nebraska, and
Colorado in the West. This min-
now is often found in small creeks,

commonly in bog streams, and
sometimes in lakes.

Breeding. — Little is known of its
spawning habits, but adhesive eggs
probably are scattered over bottom
sand, mud, or debris early in the
spring when water temperatures
reach 50° to 55° F. Growth is
slow and maturity probably is
reached at the age of 2 years with
a length of 2% to 3 inches. Larger
specimens may be raised in ferti-
lized ponds.

Food. — The food of the brassy
minnow is varied. A summary of
food studies made by two investi-
gators indicates the following per-
centages : Zooplankton, 25.9 ; phyto-
plankton, 31.6; aquatic insects,
21.3 ; plants, 3.4 ; surface drift, 16.1 ;
and silt, 1.7.

BLUNTNOSE MINNOW Hyborhynchus notatus

113

SOME IMPORTANT BAIT FISHES

LIFE HISTORY

Descriptio7i. — First obvious ray
of the dorsal fin thickened, stand-
ing out from followino; rays; scales
small and crowded behind the head ;
mouth small, horizontal, a.nd under
tlie snout; back flat and straight;
lateral line complete from head to
tail ; breeding male with a tiny
blisterlike swelling of skin at each
corner of mouth, tubercles on snout
only; spot at base of tail dark but
diffuse; body ca.vity lined with
black ; intestine less than twice body
length. The males grow larger
than the females, attaining a maxi-
mum length of 4 inches.

Range and breeding habits. —
This minnow resembles the fathead
minnow (p. 78) in appearance,
breeding ha.bits, and distribution.
It is more abundant than the fat-

head in the large, clearer lakes
and firm-bottomed streams. In
Michigan, the bluntnose has been
called tlie most conmion minnow in
inla.nd waters. Spawning begins
the latter part of May and continues
through August in Michigan, but
may begin 1 month earlier in west-
ern Minnesota. Water tempera-
tures of 70° F. or higher are neces-
sary before spawning takes place.
A female may spawn a.t least twice
in one season, and eggs are laid
under any flat object on the bottom
in water as deep as 8 feet (fig. 43),
A depth of 6 inches to 3 feet is pre-
ferred. A count of eggs in 10
females averaged 2,005 eggs per
fish. The eggs hatch in 7 to 15 days.
The young reach marketable size
by fall and spawn the following
spring. The maximum age is about
4 years.

FiouBE 43. — Spawning boards strung in pond for bluntnose minnow.

114

STONEROLLER

Food. — Because good keys for
the separation of minnow species
were not available until recent
years, much of the literature and
the records of stomach contents for
the bluntnose minnow has probably
been confused with those of the fat-
head minnow. More recent studies
indicate that the feeding habits of
these two species are similar; so the
records, general as they are, could
apply to either species.

The bluntnose minnow is known
to eat diatoms, algae, aquatic in-
sects, entomostraca.ns, fish eggs, fish
fry, and oligochaete worms. Oc-
casionally this minnow will eat its
young. Some stomachs of the
blunt-nosed minnow contain only
phytoplankton ; others, only sur-
face drift ; and others large percent-
ages of insects, higher plants, zoo-
plankton, debris, or silt. A sum-
mary of food studies by several

workers shows that, in general, the
food percentages are as follows : In-
sects, 15.9; crustaceans, 3.5; ento-
mostracans, 2; surface drift, 10.7;
annelids, 0.5 ; zooplankton, 6.9 ;
phytoplankton, 35; plants, 8.7;
algae and diatoms, 4,9; and silt and
debris, 11.8.

Importance. — T h i s minnow is
easily propagated and has been
widely introduced. It has been
propagated in Michigan at the rate
of 104,800 fish (250 pounds) an
acre. In general, this species seems
less prolific than the fathead min-
now, but in Ohio, 473,350 to an acre
of water have been raised. This
species will not withstand crowding
in minnow containers so well as the
fathead minnow. It is important
as a food for game fish, because of
its preference for large lakes where
jrame fish are abundant.

STONEROLLER Camposfoma anoma\Mm

Also called Racehorse Chub.

LIFE HISTORY

DeHcription.. — I'lump, sturdy

black crescent on dorsal fin of
adults; large tubercles on top of
mrnnowTundersiung suckerlike li^ad of breeding males; lining of
mouth with horny ridge forming abdominal cavity black, intestine
the lower lip; scales large, some- very long and wound spirally
times flecked with black pigment; around air bladder.

115

SOME IMPORTANT BAIT FISHES

Range. — The stoneroller is a min-
now of creeks and small rivers, and
prefers rocky, shady streams with
swift water. Of very wide distribu-
tion, it is common in southern Mich-
igan, Minnesota, and Wisconsin,
and is found from the St. Lawrence
southward to northern Alabama ex-
cluding the extreme southeastern
United States, and westward from
Wyomino: to Texas.

Breeding hahits. — T his fi s h
spawns from May to June 15.
(yreat numbers ascend streams,
where the bright-colored males ex-
cavate funnel-shaped cavities sev-
eral inches deep and guard these
and the eggs for a short time. The
stoneroller minnow reaches matur-
ity during its second or third sum-
mer. Males attain a size of 6 inches
and females less than 5.

Food. — The stoneroller is chiefly
a bottom feeder. It has been known

to eat algae, diatoms, small amounts
of zooplankton, a few aquatic in-
sects, and plant tissue. Sand and
clay are often found in the intes-
tinal tract, but are probably taken
along with the various foods. A
study of 20 specimens from the
Oswego River system (New York)
showed food percentages as follows :
Midge larvae, 10; diatoms, 50;
algae, 10 ; and sand and silt, 80.

ImportaTice. — The stoneroller is
tenacious of life, and is regarded as
one of the best baits for bass. In
Minnesota, it is widely sold under
the name of racehorse chub. One
dealer has experimented with prop-
agation of this minnow in shallow
ponds supplied with a slow-moving
current. The first attempts were
moderately successful, but were not
on a large enough scale to be
practical.

WESTERN MUD MINNOW Umbra llmi

LIFE HISTORY

Description. — Tail tin rounded ;
dorsal fin far back on body with
iibout 12 rays; dark vertical bar
at base of tail; scales on Head (no
other fish described in this section
l)ossesses scales there). This fish

is not a true minnow, but is re-
lated to the northern pike. It
grows to a length of 5 inches.

Range and, breeding hahits. —
This species is distributed from
Manitoba through the Great Lakes
region to Quebec and Lake Cham-

116

WESTERN MUD MINNOW

pliiiii, southward in tlie central
basin to the Upper Oliio River
system, and in northwestern Ten-
nessee, nortlieastern Arkansas, and
Kansas. It prefers sprino;-fed,
soft -bottomed pools, and weedy
streams and ponds. It is common
in bo^ijy or stagnant places.
Spawning- takes place in early
spring, usually upstream in small
brooks.

The mud minnow hibernates in
the mud and will go dow^n 4 to 9
inches. It may be found in the
mud in a horizontal position or in
a vertical position with the head
upward. When alarmed, it usu-
ally buries itself in the mud.

Food. — The food of the mud
minnow is mostly of an animal
nature. It has been known to eat
insects, spiders, mites, amphipods,
entomostracans, snails, leeches,
oligochaete w o r m s , nematodes,
earthworms, rotifers, protozoans,
and algae and other plants. A
summary of the records indicates
that mud minnows will take as
much as 80 percent of their food
from insect fauna, some have taken
90 percent amphipods, others have
taken 50 ])ercent entomostracans.
More than 20 percent of the stom-

ach contents of others has been
plant food. More than 50 percent
of the food of some stomachs has
been mollusks, and in one collec-
tion 40 percent of the stomach con-
tents was surface drift.

Stomach analyses by various
workers show^ed that the digestive
tracts of mud minnows contained
the following average percentages :
Insects, 45.6; amphipods, 11.1; en-
tomostracans, 16.3; mollusks, 12.3;
arachnids, 0.16; plants, 7.1; surface
drift, 4.6; algae, 1.4; miscellane-
ous, 1.24; and silt, 0.2.

Importance. — The mud minnow
is very hardy, but is not a popu-
lar bait species, except in Wiscon-
sin, as it is not very active.

Evermann (1901) had the fol-
lowing to say regarding this fish:

So pei'sistently do they cling to life
that it is really difficult to kill them.
* * * Its unexcelled tenacity of life is,
however, about the only thing it has to
recommend it as a bait minnow. Its
somber, unattractive color prevents it
being readily seen by game fishes, and
its tendency to pull down or get to the
bottom also militates against it. But
bass and pickerel and pike do some-
times take it and, in spite of its de-
ficiencies, the Mudfisli is a good thing to
have in one's minnow pail.

117

BIBLIOGRAPHY

Allan, Philip F.

1952. How to grow minnows. Published by the author. Fort Wcjrth, Tex.
63 pp.

Ambeus, J. L., C. M. Ambrus, and J. W. E. Harrisson.

1951. Pi-evention of Proteus hydrophilus infection (red leg disease) in frog
colonies. American Jour. Pharmacy, vol. 123, No. 4, p. 129. April.
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1954. SympcjsiunL Research on tish diseases : A review of progress during
the past 10 years. Trans. American Fisheries Soc, vol. 83, part II, pp. 217-349.
Ball, Robert C, and Edward H. Bacon.

1954. U.se of pituitary material in the propagation of minnows. U. S. Fish
and Wildlife Service, Progressive Fish-Ciilturist, vol. 16, No. 3, pp. 108-113.
July.
Bauman, Aden C.

1946. Bait minnow production in ponds. Missouri Conservationist, vol. 7,
No. 6, pp. 2-5. June.

Burrows, Roger E.

1949. Prophylactic treatment for control of fungus (f^aprolec/nia pnrasilica)

on salmon eggs. U. S. Fish and Wildlife Service, I'rogressive Fish-Culturist,

vol. 11, No. 2, pp. 97-103. April.
Cooper, Gerald P.

1935. Some results of forage fish investigations in Michigan. Trans. American
Fisheries Soc, vol. 65, pp. 132-142.

1936. Age and growth of the golden shiner (Notemigotius cnjsolcucas auratuH),
and its suitability for propagation. Papers Michigan Academy Science, Arts
and Letters, vol. 21 (1935), pp. 587-597.

Davis, Herbert S.

1947. Care and di.seases of trout. U. S. Fish and Wildlife Service, Research
Report 12. 98 pp. [Reprint.]

1953. (^ulture and diseases of game fishes. University of California I'ress,
Berkeley and Los Angeles. 332 pp.

DoDiE, John.

1948. Minnow propagation. Minnesota Department of Conservation, Bull.
No. 13. 24 pp.

EvEHtMANN, B. W.

1901. Bait minnow.s. Sixth Annual Report of New York Forest. Fi.sh and
Game Commission (1900), pp. 307-356.
Fish, Frederic F.

1938. Treat — think — and be wary, for tomorrow they may die. Some advice
on the prevention and treatment of fish diseases. U. S. Bur. Fisheries, Pro-
gressive Fish-Culturist, No. 39. \)\i. 1-9. June-July.

lf>47. A technique for controlling infectious di.sease in hatchery fish. Trans.
American Fisheries Soc, vol. 74 (1944), pp. 209-222.

118

BIBLIOGRAPHY

Hasler, Arthur D., Hans P. Thomsen. and John Neess.

1946. Facts and comments on raisinfr two common bait minnows. Wisconsin
Conservation Department, Bull. No. 210. 14 pp.

HuBBS, Carl L., and Gerald P. Cooper.

1936. Minnows of Michigan. Cranbrook Institute Science, Bull. No. 8. 95 pp.,
illus. November.
Irwin, W. H.

19 — . Commercial production of bait minnows. Oklahoma A. and M. College,
4 pp. [Mimeographed.]
Klak, George E.

1940. Neascus infestation of black-head, blunt-nosed, and other forage min-
nows. Trans. American Fisheries Soc, vol. 69 (1939), pp. 273-278.
Langlois, T. H.

1929. Breeding habits of the northern dace. Ecology, vol. 10, No. 1, pp. 161-

163. January.
1941 a. Bait culturists guide. Ohio Division Conservation and Natural Re-
sources, Bull. 137. 18 pp., 5 figs.
1941 b. Observations on bait culture. Ohio Division Conservation and Natural
Resources, Bull., pp. 18-19. August.
Markus, Henry C.

1934. Life history of the blackhead minnow {Pimephalcs inomelas). Copeia
1934, No. 3, pp. 116-122.

1939. Propagation of bait and forage fish. U. S. Bur. Fisheries, Fishery Cir-
cular 28. 19 pp., 10 figs.

McKernan, Donald L.

1940. A treatment for tapeworms in trout. U. S. Bur. Fisheries, Progressive
Fish-Culturist, No. 50, pp. 33-35. May-June.

Meehean, O. Lloyd.

1934. The role of fertilizers in pondfish pro<luction. II. Some ecological as-
pects. Trans. American Fisheries Soc, vol. 64, pp. 151-154.

1937. Control of predacious insects and larvae in ponds. U. S. Bur. Fisheries,
Progressive Fish-Culturist, No. 33, pp. 15-16. November.
RIellen, Ida M., and Robert J. Lanier.

1935. 1001 questions answered about your aquarium ; toy fishes — fresh, brackish
and salt water, also your garden pool and terrarium. Dodd, Mead and Com-
pany, New York.

O'Donnell, D. John.

1947. The disinfection and maintenance of trout hatcheries for the control of
disease, with special reference to furunculosis. Trans. American Fisheries
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1940. The breeding behavior of the common shiner, Notropis cornutus
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119

BIBLIOGRAPHY

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120

TABLE OF EQUIVALENTS

1 liter =1,000 milliliters or 1,000 grams.

1,000 liters =1,000,000 grams.

1 : 1,000 =0.1 percent.

1 : 10,000 =100 parts per million.

1 : 100,000 =10 parts per million.

1 part i^er mil-
1 i o n ( p. p.
m.) — 1 gram in 1,000 liters of water.

=1 gram in 264 gallons.

= 1 gram in 35.5 cubic feet.

=1 ounce (avoir.) in 28,350 liters.

=1 ounce (avoir.) in 7,480 gallons.

=1 ounce (avoir.) in 1,000 cubic feet.

=8.34 lbs. per million gallons.

1 part per
thousand (p.

p. th.) = 1 gram per liter.

=1 ounce (avoir.) per cubic foot.
1 part per 100

(1%) =1 gram in 100 grams of vi^ater.

= 10 grams in 1,000 grams (1 liter).
=37.8 grams in 1 gallon.
=283 grams in 1 cubic foot.

= 1 ounce in 100 ounces (avoir.) or 0.75 gallon.
=10 ounces in 1 cubic foot.
0.5% solution-. =0.7 ounce per gallon.
1% solution__.=1.3 ounces per gallon of water.
2.5% solution-. =3.3 ounces per gallon.

121

INDEX

Aeration, 40, 41-42, 54, 55

Antibiotics, 55-56, 57

Bacterial disease, 53, 55, 57, 58-59

Baltimore minnow, 100

Birds, control, 63, 87

Black grub, 59-60, 63

Blacknose dace, 105-106

Black spot, 59-60

Blue minnow, 112

Bluntnose minnow, 113-115

Brassy minnow, 43, 44, 113

Campostoma anornalum, 115

Carassius auratus, 100

Catostomus commersonnii, 68

Chrosomus eos, 108

Chrosomus erythrogasler, 109

Chub:

Creek, 85-94

Hornyhead, 103-104

Racehorse, 115

Rainbow, 107

Redtail, 103

River, 104-105
Columnaris, 58
Common shiner, 111-112
Common sucker, 68
Copepods, 55, 57, 61
Counting fish, 37-39, 73-74, 79, 91, 95
Crayfish, 27, 65
Creek chub, 85-94
Dace:

Blacknose, 105-106

Finescale, 107-108

Horned, 85

Longnose, 106-107

Northern, 102

Northern redbelly, 108-109

Pearl, 102-103

Southern redbelly, 109-110

Yellowbelly, 108
Dams, 9-13
Dipping diseased fish, 43, 44, 53-54, 57,

58, 60
Diseases and parasites, 50-61

122

Disinfecting, 37, 43-44, 61-62

Dropsy, 58

Dry fallowing, 24

Emerald shiner, 110

Equivalents, table, 121

External parasites, 52, 53, 54, 55, 57,

59-61, 62
Fathead minnow, 27, 78-85
Feeding, 27-28, 43, 45, 75, 77-78, 82-83,

93-94, 98-99, 102
Fertilizing, 24-26, 49, 75-76, 82, 84, 101
Finescale dace, 107-108
Fin rot, 53, 55, 58
Flatworms, 59-60
Flushing diseased fish, 52-53
Fungus disease, 40, 42, 52, 54, 57-58
FuruncuJosis, 55, 56, 59
Gear, care, 37, 43, 62
Gill disease, 53, 54, 55
Golden shiner, 27, 94-100
Goldfish, 100-102
Grading fish, 39, 76, 85
Grass minnow, 113
Hardening eggs, 71
Hardening fish, 29-37, 76-77, 84-85, 94,

99, 102
Hatching eggs, 72-73, 92
Herbicides, 46-50
Holding fish, 42-45, 77-78, 84-85, 94,

99-100
Horned dace, 85
Hornyhead chub, 103-104
Hyhognathus hankinsoni, 113
Hybopis (Nocomis) micropogon, 104
Hyborhynchus noiatus, 113
Indiana minnow, 100
Insect control, 62-63
InternaUtreatment, 56-57
Intestinal infections, 56, 57
Lake shiner, 44
Leatherback, 108
Leatherback minnow, 102
Live box, 29, 76
Longnose dace, 106-107

INDEX

Margariscus margarita, 102
Minnow:

Baltimore, 100

Blue, 112

Bluntnose, 113-115

Brassy, 43, 44, 113

Fathead, 27, 78-85

Grass, 113

Indiana, 100

Leatherback, 102

Missouri, 100

Silvery, 27

Tuffy, 78

Western mud, 116-117
Missouri minnow, 100
Muskrat damage, 65
Nets, 34-37, 43
Northern dace, 102
Northern redbelly dace, 108 109
Notemigonus crysoleucas, 94
Notropis atherinoides, 110
Noiropis cornutus, 111
Notropis spilopterus, 112
Parasites, 50-56, 57, 59-61
Pearl dace, 102-103
Pfrille neogaea, 107
Pimephales promelas, 78
Pituitary injection, 92
Plant control, 45-50
Ponds:

Artificial, 4-20, 103

Growing, 45, 80, 82-83, 92-93, 96, 98

Holding, 44-45, 71, 77

Natural, 21-22, 75, 76, 78, 92, 95, 96-97,
98, 99
Predacious fish, 63-64, 82, 87
Predator control, 62-65
Prolonged treatment, 54-56, 60, 61
Racehorse chub, 115
Raceway, 86-89
Rainbow chub, 107
Redtail chub, 103
Rhinichthys atratulus, 105
Rhinichthys cataractae, 106
River chub, 104-105
Roach, 94

Salamander, 64-65

Salt treatment, 42, 51-52, 57. 60

Seines, 29-30, 76

Semotilus airomaculatus, 85

Shiner:

Common, 111-112

Emerald, 110

Golden, 27, 94-100

Lake, 44

Spotfin, 112
Silvery minnow, 27
Skipjack, 111
Slicker, 105
Snakes, 63

Sorting fish, 39, 76, 85
Southern redbelly dace, 109-110
Spawning raceway, 86-89
Spotfin shiner, 112
Stocking:

Adults, 26-27, 80-81, 84, 89-90, 97-98,
101

Fry, 74-75, 80-81, 82, 93, 98
Stoneroller, 115-116
Stripping, 71, 86, 92, 106, 111
Sucker, 68-78
Sulfa drugs, 56-57, 59
Tanks, 40-44, 85, 94
Tapeworm, 56, 57, 60
Tempering. — See Hardening fish.
Transporting fish, 40-42
Traps, 30-34
Tuff}' minnow, 78
Turtles, 63
Ulcer disease, 55
Umbra limi, 116
Water supply, 5-7

Water temperature, 40, 42, 44, 54, 58, 69,
71, 72, 79, 81, 83, 84, 85, 89, 91,
93, 94, 96, 98, 99, 100, 103, 104,
106, 109, 113, 114
Weed Control, 45-55
Weighing fish, 37-39
Western mud minnow, 116-117
White sucker, 68-78
Worms, parasitic, 56, 57, 59-60
Yellowbelly dace, 108
Yellow grub, 63

123

NOTES

124

, S. GOVERNMENT PRINTING OFFICE; 1956 O— 36791 3

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