• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Table of Contents
 Introduction
 Fingerling production
 Raising food fish
 Back Cover














Group Title: Circular - Florida Cooperative Extension Service ; 710
Title: Catfish farming in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00072581/00001
 Material Information
Title: Catfish farming in Florida
Series Title: Circular (Florida Cooperative Extension Service)
Physical Description: 17 p. : ill. ; 31 cm.
Language: English
Creator: Walsh, S. J
Lindberg, W. J
Publisher: Univ. of Fla.
Place of Publication: Gainesville Fla
Publication Date: 1986
 Subjects
Subject: Fish culture -- Florida   ( lcsh )
Catfishes -- Florida   ( lcsh )
Genre: non-fiction   ( marcgt )
 Notes
Statement of Responsibility: S.J. Walsh and W.J. Lindberg.
 Record Information
Bibliographic ID: UF00072581
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 20664762

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page
    Table of Contents
        Table of Contents
    Introduction
        Page 1
    Fingerling production
        Page 1
        Brood stock management
            Page 1
            Page 2
        Spawning management
            Page 3
            Page 4
        The hatchery
            Page 5
        Fry management
            Page 6
            Page 7
        Raising fingerlings
            Page 8
            Page 9
            Page 10
    Raising food fish
        Page 11
        Rearing facilities
            Page 11
            Page 12
        Water quality
            Page 13
        Stocking
            Page 14
        Feeding
            Page 14
        Disease and pest control
            Page 15
        Harvesting and processing
            Page 16
            Page 17
    Back Cover
        Back Cover
Full Text



Circular 710


July 1986


S.J. Walsh and W.J. Lindberg


Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences I University of Florida / John T. Woeste, Dean






















CaO#/& 'admiin




S. J. Walsh and W.J. Lindberg*
















*Graduate student, Department of Zoology and the Florida State Museum; and Assistant Professor Aquaculture Extension Specialist, Depart-
ment of Fisheries and Aquaculture, Institute of Food and Agricultural Sciences; University of Florida, Gainesville, FL 32611.
Cover illustration adapted by Darrae Norling from Atlas of North American Freshwater Fishes, North Carolina State Museum of Natural History.
Graphic design by Kelly Hancock.







Contents



Introduction .... .. ..... ........ 1
Fingerling Production. .. .................................. 1
Brood Stock Management. ....... ...................................... 1
Selection of Brood Stock. ..................................... 1
Determining Sex .......... ................................... .... 2
N nutrition ................................ ........ 3
Stocking ........................ ......... 3

Spawning Management ............................................... 3
Use of Spawning Shelters. ....... ................................... 3
Spawning Methods ............................................ ......... 4

The Hatchery ................................................... ......... 5
Trough Construction ............... ................................... 5
Water Quality............ ....................................... ....... 6
Disease Control....................................................... 6

Fry Management ........................................................ 6
Handling Fry ............... ............................................. 6
Counting Fry ............................................................ 7
Feeding Fry ............................................................ 7

Raising Fingerlings ........... ........................................ 8
Pond Preparation and Pest Control ............ .......................... 8
Stocking Fry ..... .................................................. 8
Feeding Fingerlings. ............... ..................... 9
Harvesting ................................ ............................ 9
G reading .................................. .................. ........ 10
Counting ............ ....... ................... ............... .........10
Transporting Fingerlings .......... .................................11
Raising Food Fish. ... ............... ...........................11
Rearing Facilities ...................................... ................11
Pond Construction. ...................................... 11
Alternative Facilities ................ ................... ................... ..12

Water Quality ............ ........ ................... ............... .........13

Stocking .................. .. ............ ....................... .........14
Acclimating Fingerlings ................................... .................. 14

Feeding .................................................................. 14
Disease and Pest Control ..................................... ................. 15
Diseases and Parasites ................................... .................. 15
Weed Control ......... ....................................................15
Other Pests ............. ................... ................. ......... 16

Harvesting and Processing ............. ................... ................. 16









INTRODUCTION


Commercial catfish farming is an important
agricultural industry in the United States, although
Florida has lagged behind other southeastern states. More
than 100,000 acres of water are currently used to pro-
duce around 225 million pounds of catfish yearly in the
United States. Of this market, about 275,000 pounds of
food-sized fish were raised on 88 acres in Florida during
1981. The low commercial production of catfish in
Florida, compared with other southeastern states, is
primarily the result of marketing and environmental con-
straints. A lack of adequate processing facilities for farm-
raised fish and soils that are not suited for large, con-
ventional embankment ponds have impeded development
of the catfish aquaculture industry in the state.
Nonetheless, catfish farmers are increasing their
endeavors in Florida and prospects for future develop-
ment of the industry may be promising.
This publication addresses the basic techniques and
procedures used in culturing catfish and is intended to
be a general guide for the farmer who is contemplating
raising catfish in Florida on a commercial basis. Catfish
farmers often specialize either in producing food-sized
fish for processing and marketing to wholesale and retail
outlets, or in spawning and rearing fry and fingerlings
for stocking to grow-out ponds and other aquatic systems
(e.g., raceways and cages).
Before building facilities and attempting to raise cat-
fish, one must become thoroughly familiar with
marketing potential, investment costs, and environmen-
tal constraints that apply to a given area. Prices of farm-
raised catfish for consumption are currently non-
competitive with wild-caught fish in Florida. Moreover,
consumers in the state seem to have a preference for
"shorts" or sharpiess," i.e., fish of a relatively small-
sized dressed carcass (2-5 ounces). Farmers who may be
considering production of food fish should investigate
marketing outlets for their product well before construct-
ing facilities and stocking fish. Likewise, anyone intend-
ing to produce fingerlings for sale as seed stock should
be sure that they will be able to sell and transport their
fish successfully. Producers must make a preliminary
assessment of expected economic expenditures and
returns to determine the potential profitability of catfish
farming. The greatest capital outlays will be land, pond
construction, equipment, and supplies. Major operating
costs are feed, fingerlings (for rearing as food fish), labor,
fuel, electricity, chemicals, and processing or transpor-
tation costs. A marketing analyst should be consulted for
assistance in estimating economic investments and prof-
its. Environmental constraints such as the feasibility of


pond construction, and water quality and quantity must
be carefully considered when planning a fish farm and
making an economic analysis.
Several unique features of Florida's topography,
climate, and aquatic systems show promising avenues for
development of the catfish farming industry. Construc-
tion of appropriate ponds for culturing catfish may be
severely limited by soil types and topography throughout
much of the state except in parts of the panhandle.
However, there may be good potential for rearing fish
by nontraditional methods such as in raceways or in cages
placed in canals, borrow pits, or other suitable bodies of
water. Because of the warm climate and long growing
season, Florida farmers could possibly supply fingerlings
or fresh food fish to markets in other states out-of-season
or on a year-round basis. Cultivation of yellow bullheads
(Ictalurus natalis), brown bullheads (I. nebulosus), white
catfish (I. catus), or other species could provide alter-
natives to rearing channel catfish (I. punctatus). Some
of these species might be suitable for supplementing cur-
rent consumer markets, and they may be more amenable
to culture under certain conditions than are channel cat-
fish. However, culture techniques are best known for
channel catfish, and the methods and procedures outlined
here are those that apply principally to channel catfish
unless otherwise noted.



FINGERLING PRODUCTION

Brood Stock Management

Selection of Brood Stock
Successful fingerling producers select high quality
brood fish and maintain them in good health to obtain
maximum yields of offspring. Many catfish producers
prefer to buy mature fish rather than waiting for finger-
lings to reach spawning age. The best source of brood
fish is a reputable hatchery. However, be careful not to
buy culls, or fish that have been discarded because they
have undesirable traits. Fish-farming trade magazines
usually carry advertisements for brood stock available
through established producers and growers. It is advisable
to inspect brood fish closely before buying to ensure that
healthy fish are obtained.
Avoid purchasing fish recently taken from the wild,
since they are often unreliable spawners and their finger-
lings may grow more slowly and be less resistant to
diseases than fingerlings from established hatchery stocks.









INTRODUCTION


Commercial catfish farming is an important
agricultural industry in the United States, although
Florida has lagged behind other southeastern states. More
than 100,000 acres of water are currently used to pro-
duce around 225 million pounds of catfish yearly in the
United States. Of this market, about 275,000 pounds of
food-sized fish were raised on 88 acres in Florida during
1981. The low commercial production of catfish in
Florida, compared with other southeastern states, is
primarily the result of marketing and environmental con-
straints. A lack of adequate processing facilities for farm-
raised fish and soils that are not suited for large, con-
ventional embankment ponds have impeded development
of the catfish aquaculture industry in the state.
Nonetheless, catfish farmers are increasing their
endeavors in Florida and prospects for future develop-
ment of the industry may be promising.
This publication addresses the basic techniques and
procedures used in culturing catfish and is intended to
be a general guide for the farmer who is contemplating
raising catfish in Florida on a commercial basis. Catfish
farmers often specialize either in producing food-sized
fish for processing and marketing to wholesale and retail
outlets, or in spawning and rearing fry and fingerlings
for stocking to grow-out ponds and other aquatic systems
(e.g., raceways and cages).
Before building facilities and attempting to raise cat-
fish, one must become thoroughly familiar with
marketing potential, investment costs, and environmen-
tal constraints that apply to a given area. Prices of farm-
raised catfish for consumption are currently non-
competitive with wild-caught fish in Florida. Moreover,
consumers in the state seem to have a preference for
"shorts" or sharpiess," i.e., fish of a relatively small-
sized dressed carcass (2-5 ounces). Farmers who may be
considering production of food fish should investigate
marketing outlets for their product well before construct-
ing facilities and stocking fish. Likewise, anyone intend-
ing to produce fingerlings for sale as seed stock should
be sure that they will be able to sell and transport their
fish successfully. Producers must make a preliminary
assessment of expected economic expenditures and
returns to determine the potential profitability of catfish
farming. The greatest capital outlays will be land, pond
construction, equipment, and supplies. Major operating
costs are feed, fingerlings (for rearing as food fish), labor,
fuel, electricity, chemicals, and processing or transpor-
tation costs. A marketing analyst should be consulted for
assistance in estimating economic investments and prof-
its. Environmental constraints such as the feasibility of


pond construction, and water quality and quantity must
be carefully considered when planning a fish farm and
making an economic analysis.
Several unique features of Florida's topography,
climate, and aquatic systems show promising avenues for
development of the catfish farming industry. Construc-
tion of appropriate ponds for culturing catfish may be
severely limited by soil types and topography throughout
much of the state except in parts of the panhandle.
However, there may be good potential for rearing fish
by nontraditional methods such as in raceways or in cages
placed in canals, borrow pits, or other suitable bodies of
water. Because of the warm climate and long growing
season, Florida farmers could possibly supply fingerlings
or fresh food fish to markets in other states out-of-season
or on a year-round basis. Cultivation of yellow bullheads
(Ictalurus natalis), brown bullheads (I. nebulosus), white
catfish (I. catus), or other species could provide alter-
natives to rearing channel catfish (I. punctatus). Some
of these species might be suitable for supplementing cur-
rent consumer markets, and they may be more amenable
to culture under certain conditions than are channel cat-
fish. However, culture techniques are best known for
channel catfish, and the methods and procedures outlined
here are those that apply principally to channel catfish
unless otherwise noted.



FINGERLING PRODUCTION

Brood Stock Management

Selection of Brood Stock
Successful fingerling producers select high quality
brood fish and maintain them in good health to obtain
maximum yields of offspring. Many catfish producers
prefer to buy mature fish rather than waiting for finger-
lings to reach spawning age. The best source of brood
fish is a reputable hatchery. However, be careful not to
buy culls, or fish that have been discarded because they
have undesirable traits. Fish-farming trade magazines
usually carry advertisements for brood stock available
through established producers and growers. It is advisable
to inspect brood fish closely before buying to ensure that
healthy fish are obtained.
Avoid purchasing fish recently taken from the wild,
since they are often unreliable spawners and their finger-
lings may grow more slowly and be less resistant to
diseases than fingerlings from established hatchery stocks.









INTRODUCTION


Commercial catfish farming is an important
agricultural industry in the United States, although
Florida has lagged behind other southeastern states. More
than 100,000 acres of water are currently used to pro-
duce around 225 million pounds of catfish yearly in the
United States. Of this market, about 275,000 pounds of
food-sized fish were raised on 88 acres in Florida during
1981. The low commercial production of catfish in
Florida, compared with other southeastern states, is
primarily the result of marketing and environmental con-
straints. A lack of adequate processing facilities for farm-
raised fish and soils that are not suited for large, con-
ventional embankment ponds have impeded development
of the catfish aquaculture industry in the state.
Nonetheless, catfish farmers are increasing their
endeavors in Florida and prospects for future develop-
ment of the industry may be promising.
This publication addresses the basic techniques and
procedures used in culturing catfish and is intended to
be a general guide for the farmer who is contemplating
raising catfish in Florida on a commercial basis. Catfish
farmers often specialize either in producing food-sized
fish for processing and marketing to wholesale and retail
outlets, or in spawning and rearing fry and fingerlings
for stocking to grow-out ponds and other aquatic systems
(e.g., raceways and cages).
Before building facilities and attempting to raise cat-
fish, one must become thoroughly familiar with
marketing potential, investment costs, and environmen-
tal constraints that apply to a given area. Prices of farm-
raised catfish for consumption are currently non-
competitive with wild-caught fish in Florida. Moreover,
consumers in the state seem to have a preference for
"shorts" or sharpiess," i.e., fish of a relatively small-
sized dressed carcass (2-5 ounces). Farmers who may be
considering production of food fish should investigate
marketing outlets for their product well before construct-
ing facilities and stocking fish. Likewise, anyone intend-
ing to produce fingerlings for sale as seed stock should
be sure that they will be able to sell and transport their
fish successfully. Producers must make a preliminary
assessment of expected economic expenditures and
returns to determine the potential profitability of catfish
farming. The greatest capital outlays will be land, pond
construction, equipment, and supplies. Major operating
costs are feed, fingerlings (for rearing as food fish), labor,
fuel, electricity, chemicals, and processing or transpor-
tation costs. A marketing analyst should be consulted for
assistance in estimating economic investments and prof-
its. Environmental constraints such as the feasibility of


pond construction, and water quality and quantity must
be carefully considered when planning a fish farm and
making an economic analysis.
Several unique features of Florida's topography,
climate, and aquatic systems show promising avenues for
development of the catfish farming industry. Construc-
tion of appropriate ponds for culturing catfish may be
severely limited by soil types and topography throughout
much of the state except in parts of the panhandle.
However, there may be good potential for rearing fish
by nontraditional methods such as in raceways or in cages
placed in canals, borrow pits, or other suitable bodies of
water. Because of the warm climate and long growing
season, Florida farmers could possibly supply fingerlings
or fresh food fish to markets in other states out-of-season
or on a year-round basis. Cultivation of yellow bullheads
(Ictalurus natalis), brown bullheads (I. nebulosus), white
catfish (I. catus), or other species could provide alter-
natives to rearing channel catfish (I. punctatus). Some
of these species might be suitable for supplementing cur-
rent consumer markets, and they may be more amenable
to culture under certain conditions than are channel cat-
fish. However, culture techniques are best known for
channel catfish, and the methods and procedures outlined
here are those that apply principally to channel catfish
unless otherwise noted.



FINGERLING PRODUCTION

Brood Stock Management

Selection of Brood Stock
Successful fingerling producers select high quality
brood fish and maintain them in good health to obtain
maximum yields of offspring. Many catfish producers
prefer to buy mature fish rather than waiting for finger-
lings to reach spawning age. The best source of brood
fish is a reputable hatchery. However, be careful not to
buy culls, or fish that have been discarded because they
have undesirable traits. Fish-farming trade magazines
usually carry advertisements for brood stock available
through established producers and growers. It is advisable
to inspect brood fish closely before buying to ensure that
healthy fish are obtained.
Avoid purchasing fish recently taken from the wild,
since they are often unreliable spawners and their finger-
lings may grow more slowly and be less resistant to
diseases than fingerlings from established hatchery stocks.









Be especially careful to avoid any sources having a history
of channel catfish virus disease, since this pathogen is un-
treatable and can spread quickly and destroy an entire
stock. Inbred strains are less desirable than genetically-
superior crossbred strains. Healthy brooders should be
full-bodied and free of sores or hemorrhages on the skin.
Thin or emaciated fish may be old, diseased, or underfed.
Catfish farmers generally prefer brooders in the 2-10
pound range; smaller females do not produce as many
eggs as larger ones, and bigger fish may be difficult to
handle. Channel catfish reach optimal breeding condi-
tion in three to four years, when 40-50% of the fish may
be expected to spawn under good conditions. Scientists
are currently attempting to breed strains that will mature
earlier. Proper nutrition of mature fish throughout the
year is essential to ensure successful spawning, because
the number and size of eggs produced by a female is
strongly influenced by diet.
It is important to select the proper ratio of male and
female brooders. A ratio of two or three females for each
male is ideal. One male can mate with two or more
females in a single spawning season if the eggs are moved
to a hatchery or incubation chamber. Although catfish
normally produce offspring in a 1:1 sex ratio, do not take
this for granted when buying brooders. Males grow faster
than females, so when fish reach 2-3 pounds, up to 80%
of the largest individuals in the population may be males.
It is advisable to determine the sex of each brooder you
buy to ensure a proper ratio of males and females.

Determining Sex
Both primary and secondary sex characteristics are
useful in distinguishing males and females. Primary sex
characteristics are those features specifically involved in
reproduction, whereas secondary sex characteristics are
not directly involved in spawning. The primary
characteristic used to distinguish the sexes is the urogenital
opening; the secondary characteristics relate to coloration
and body shape.


Male (left), female (right).


Male (right), female (left).

Secondary characteristics are most prominent during
the spawning season. Males are usually larger and have
broader heads than females of the same age. As the
spawning season approaches, males become lean, develop
large muscular heads that are wider than their bodies, and
sometimes become darker, especially on the lower jaw.
Females' heads are narrower than their bodies when
viewed from above. They also develop soft, greatly
distended bellies as the spawning season approaches.
Preliminary identification of sex should be confirmed
by examining the urogenital opening. This is particularly
important with young fish and during the fall or winter
when secondary sex traits are less pronounced. With prac-
tice, one can reliably use the following method to deter-
mine the sex of fish as small as one pound:
The fish should be turned upside down for examina-
tion of the genital area, which can be seen as a fleshy area
about midway between the pelvic and anal fins. Two
openings should be visible when examined closely: the one
nearest the head is the anus, and the one nearest the tail
is the genital pore. In males the genital pore terminates
on a fleshy, nipple-like structure (the genital papilla),
which usually becomes swollen and somewhat rigid as
spawning season nears. The genital area of females is oval
and flat, with the anus separated from two other open-
ings by a small flap of skin. The slit or groove toward
the tail end contains a urinary pore and the genital pore.
Immediately prior to and during the spawning season,
the entire genital area of the female becomes red, swollen,
and may be covered with a thin layer of mucus.
A probe is useful in determining the sex, especially in
young or nonbreeding fish. Immobilize the fish by
holding it belly upward with one hand grasping the head
and the other hand firmly holding the tail region. With
the fish's head below your chest and the tail held away
from your body, arch the fish's belly upward. This will
allow the male genital papilla or the female slit to become
more visible. Then have an assistant carefully and gently










slide a blunt probe, such as a thin wire, over the genital
area toward the tail, with the point leading the probe.
Be cautious not to break the skin or penetrate the flesh
with the probe. If the point of the probe catches in the
genital opening, the fish is most likely a female. Draw-
ing the probe across the genital area in the opposite direc-
tion, from the tail side toward the head, should cause the
probe to catch on the genital papilla if the fish is a male.

Nutrition
Good spawning success requires a proper diet for
brooders, especially in the fall and early spring months.
During warm weather feed a nutritionally complete diet
of about 35-40% protein at a concentration of 1-2% of
the stock body weight daily (Table 1). Catfish do not re-
quire feeding when water temperature falls below 50 F
(10 C). When water temperature is between 500 and 65
F (10-18 C), feed approximately 0.50-0.75% of the
fishes' body weight three times per week. Estimate the
amount to feed by observing feeding vigor, if possible.
This can best be accomplished by using a floating pellet.
During warm weather, the proper amount of food to of-
fer is that which will be eaten in about 10 minutes.
Feeding activity declines when the spawning season begins
and during cold weather.
Table 1. Recommended brood fish diet.

Ingredient Percent of Total
Soybean meal (44% protein) 50.5
Ground corn 14.93
Wheat shorts 6.0
Distillers dried solubles 7.5
Fish meal 15.0
Animal fat 3.0
Pellet binder 2.5
Dicalcium phosphate 0.5
Vitamin premix 0.75
Coated vitamin C 0.057
Trace mineral mix 0.075

Analysis:
Total crude protein 35.6%
Digestible energy 2640 kcal/kg
Energy to protein ratio (kcal/g) 7.3 : 1.0

Stocking
Total weight of brood fish should not exceed 1200
pounds per acre at any time, hence ponds should be
stocked initially at about 800 pounds of fish per surface
acre to allow for weight gain. Successful spawners should
gain about 50% of their weight from one spawning season
to the next. Old, sick, and undesirable brood fish should
be removed each spring and replaced with young brooders
to maintain the total initial stocking density and to
enhance vigor and productivity by reducing inbreeding.


The most popular brood ponds in more northern states
are between 1 and 10 acres; smaller ponds may undergo
extreme temperature changes and reduce spawning suc-
cess, while larger ponds are difficult to manage. Problems
with pond construction, temperature control, and weed
management in Florida waters dictate that the most con-
venient size for brood ponds should be '/,o-l acre. Brood
fish should be stocked in more than one pond to minimize
the likelihood of wholesale destruction of an entire stock
from disease, oxygen depletion, or other catastrophes.

Spawning Management

Channel catfish begin spawning in late spring when
water temperature reaches about 75 oF (24 C). Males
prepare nests in hollow logs or similar shelters and ag-
gressively attack intruders. A female that is attracted to
a nest will mate with the male over a period of several
hours, depositing a large, yellow, jellylike egg mass. The
number of eggs laid is dependent on the size of the female
and averages around 2,000-3,000 per pound of body
weight. A one pound egg mass will contain about
10,000-11,000 eggs. After spawning, the male chases the
female away and guards the eggs. A single male may
spawn with more than one female in one season.

Use of Spawning Shelters
Artificial spawning containers should be provided to
enhance spawning success and facilitate removal of eggs
and young. Commonly used items include milk cans, nail
kegs, ceramic or earthenware crocks, wooden boxes, am-
munition cans, and plastic or metal buckets and drums.
The spawning receptacle must be of sufficient size to ac-
commodate the brooding pair and should have an open-
ing just large enough for them to pass through. A hinged
lid will make it easier to check for spawning and to
remove eggs.
Spawning containers should be provided for 50-90%
of the males, by placing containers in water 12-30 inches
deep, 1-10 yards apart, and with the opening toward the
pond center. Each nest container can be marked with a
float or flag to indicate its position.
Containers should be placed in ponds at a time ap-
propriate for the target date of fingerling production.
Most spawning occurs at water temperatures between 75
and 85' F (24'-30 C), with an optimum around 800 F
(27 C). Because of the large latitudinal temperature gra-
dient in Florida, channel catfish can be expected to spawn
at quite different times between about March and July
throughout the state. As a result, more southern farms
may have the greatest potential for supplying early seed
stock to markets in the north.
Spawning activity sometimes diminishes for no ap-
parent reason. Additional spawning may often be
stimulated by lowering the water level of the pond about









one foot and then rapidly refilling the pond, or by occa-
sionally moving unoccupied containers. Since not all
females spawn and a proportion of the eggs, fry, and
fingerlings do not survive, about 1,000 fingerlings will
be produced per pound of healthy female brooder if
proper brood stock, hatchery, and rearing techniques are
used.

Spawning Methods
A variety of methods are commonly used to spawn cat-
fish. Some producers attempt to induce spawning by in-
jecting brooders with hormones. Such injections may be
useful in stimulating fish to breed out-of-season or in un-
natural enclosures such as pens and aquaria. Catfish will
respond to intraperitoneal injections of pituitary extract
from carp and other fish, as well as synthetic hormones.
Carp pituitary is typically given in doses of about 6 mg
per pound (450 g) of fish in three injections over 24 to
48 hours. Prespawning catfish also respond well to a
single injection of human chorionic gonadotropin (HCG)
at an optimum dose of about 800 International Units
(I.U.) per pound (450 g). Both ripe males and females
may be injected. The following methods are the most
popular techniques used in spawning catfish:

1. Spawning and Rearing Pond Method
This method requires the least skill, labor, and facilities.
Spawning containers are placed in the pond, and the fish
are allowed to spawn and hatch the eggs. Fry are left in
the pond and cultured until ready for harvest. This
method is unreliable, causes ponds to contain different
size and age groups, and is not recommended for com-
mercial production of catfish. In some cases it is a suitable
method of producing catfish for recreational angling or
noncommercial harvest.

2. Egg Transfer Method, Open Pond Spawning
This method is a productive way to spawn catfish but re-


Removal of egg mass from spawning container.


quires great technical and financial expenditure. Brooders
are allowed to spawn in containers within the pond, but
the fertilized eggs are removed and incubated in a hatch-
ery. Removal of eggs minimizes the spread of diseases
and parasites from the adults to the young, reduces preda-
tion on fry by the adults, and provides easier means to
control stocking densities.
Spawning containers should be examined every two to
four days, preferably in the late morning or afternoon,
since most spawning probably occurs during the night or
early morning. Eggs should be carefully removed as soon
as they are found. Since male catfish aggressively defend
their nests and can inflict painful bites, it is advisable to
wear gloves and exercise caution when removing eggs or
fry. Disturbed males may also eat or dislodge their eggs,
so it is sometimes best to first chase the male away from
the spawning container.
The adhesive egg mass should be gently scraped free of
the floor of the container using a plastic spatula or similar
device, and then carefully lifted into a bucket containing
pond water. Eggs may be left in a bucket in the shade
for 10 to 20 minutes, but if they are near hatching or if
transport to the hatchery will be longer, aeration should
be provided. Never place eggs in direct sunlight or
transport them in coolers and other tightly covered con-
tainers that might result in suffocation.

3. Fry Transfer Method, Open Pond Spawning
This method is similar to the egg transfer method, ex-
cept that the male brooder is allowed to incubate the eggs
until hatching. Newly-hatched fry are transferred from
the spawning containers to the hatchery or nursery ponds.
Spawning containers should be checked every three days,
and when an egg mass is found a small clump of eggs
should be gently pinched off and examined closely to
determine the approximate age of the clutch (Table 2).
Table 2. General characteristics used to estimate the age
of channel catfish eggs.
Approximate
Age** Estimated Days
Egg Appearance (780 F) to Hatching
No pulsations < 24 hours 7-8
Pulsating motions 1-2 days 6-7
Faint bloody streak 2-3 days 5-6
Blood throughout
egg 3-4 days 4-5
Eyes visible 4-5 days 3-4
Entire fish visible,
embryo occasion-
ally twists or moves 5-6 days 2-3
No bloody streaks 6-7 days 1-2
Hatching begins 7-8 days 0-1
* *For every 20 F above or below 780 F, subtract or add
one day to hatching time, respectively.
Remove the fry one day after the predicted hatching date.
Newly-hatched fry have a large yolk sac that impedes their


























Spawning pens.


movement, but they are still capable of swimming. Fry
can be carefully caught with a small fine-mesh net or gen-
tly poured into a bucket of pond water and transferred
to the nursery. After counting the fry (see "Counting
Fry"), they should be released into the nursery by slowly
submerging the bucket. If the water temperature of the
nursery differs from that of the brood pond, be sure to
properly acclimate the fry as during hauling and stocking.

4. Pen Spawning
Pen spawning uses submerged enclosures made of wood,
concrete, wire mesh, or a combination of materials.
Although this method requires additional construction
and labor costs, it has the advantage of allowing selec-
tive mating. Pen spawning techniques are not currently
in wide use in Florida, but there may be good potential
for this method in pit ponds, canals, sinkhole and solu-
tion lakes, reclaimed phosphate pits, and other aquatic
systems unusual or unique to the state.
Pens are usually built in at least 3 feet of water along a
bank to minimize the amount of materials needed and
for ease of observing and handling fish. Galvanized chain
link fence, plastic-coated wire mesh, or other nonrusting
materials should be used to construct rectangular pens
about 4 x 6 feet and extending 12-24 inches above the
water surface, with the narrow side open against the
shoreline. Adjacent pens can have common sides to fur-
ther reduce construction costs. Sides of the pen must be
embedded in the bottom to prevent brood fish from
escaping. Mesh size must be large enough to allow for
good water circulation, but not so large as to permit the
escape of brood fish; meshes of V2-2 inches are usually
satisfactory. A spawning container is placed in the pen,
usually with the receptacle opening toward the center of
the pond.
A pair of ripe brood fish of similar size should be in-
troduced into each pen. It is important to select fish,
especially females, that are nearly ready to spawn. Some
producers who use this method prefer to inject brood fish
with spawning hormones a day or two before placing


them in the pens. Cages should then be checked daily and
any female that is being harassed or injured by a male
should be removed at once. It is very important to
transfer the female soon after spawning to prevent her
from being seriously injured or killed by the male.
Following spawning, eggs may be moved to the nursery
or the male may be allowed to incubate them to hatching.
If spawning does not occur in one to two weeks, double-
check the sexes of the pair and exchange brood fish if
necessary.

5. Tank Method
Tank or aquarium spawning is the most intensive method
of spawning management because it requires considerable
investments of time, labor, and facilities. Aquaria, tanks,
or troughs of at least 50 gallons (200 liters) are used as
spawning enclosures. A pair of ripe brooders is selected
and spawning is induced by injecting the female or both
fish with pituitary extract or HCG. Depending on the
dose of hormone, spawning usually ensues within a day
or two of injection, but some females may require addi-
tional injections. As soon as spawning is completed, the
eggs are transferred to the hatchery and the aquarium can
be stocked with a new brood pair, or the same male can
be used with a fresh female following a resting period.
The tank method has several advantages over other
techniques: (1) variables such as temperature, light, and
water chemistry can often be controlled more easily; (2)
spawning period can sometimes be altered, allowing for
earlier seasonal production of fry or limiting spawning
to times that are convenient for the culturist; (3) fish that
might not otherwise spawn may often be induced to; (4)
diseases and parasites can be more easily controlled; (5)
selected matings can be performed and easily recorded.
Major disadvantages of the tank method are that (1) there
are greater risks of losses from power outages, plugged
pipes, and other mechanical failures; (2) the number of
eggs produced per man-hour may be lower than other
methods; (3) the tank method is comparatively expensive.


The Hatchery

The most efficient hatcheries use incubation chambers
for hatching eggs, since predation, cannibalism, and
disease can be reduced and stocking rates can be easily
monitored. Hatcheries range from simple wooden pad-
dlewheel troughs to more sophisticated devices available
through commercial equipment suppliers. Hatcheries
need not be elaborate, so long as good water quality and
disease control measures are maintained.

Trough Construction
A typical incubation chamber consists of a flat-
bottomed wooden, fiberglass, aluminum, or stainless steel
(14-gauge) trough about 8 to 10 feet long, 18 to 24
inches wide, and 10 to 12 inches deep (about 100 gallons).


























Hatchery trough with paddles.


Some hatcheries have a divider in the middle of the trough
for reinforcement and to allow eggs of different ages to
be incubated at the same time. To provide adequate aera-
tion, troughs are equipped with a series of paddles made
of galvanized tin or similar material. Paddles should be
mounted above the center of the trough on a one-inch
pipe shaft, driven by an electric motor at 30 rpm. Pad-
dles should be spaced at appropriate widths to accom-
modate six to eight wire-mesh baskets in which eggs are
suspended. Baskets made of 4 inch plastic-coated hard-
ware cloth and about 3 inches deep are hung by wires
from the sides of the trough so the waterline is just below
the basket tops. Paddles should be long enough to reach
well below the baskets to gently roll the egg masses and
force oxygen-rich water through them. Water should be
supplied to one end of the trough at a rate that will allow
one complete water exchange in about 45 to 60 minutes
(about 2 to 3 gallons per minute in a 100-gallon trough).
A standpipe may be fitted into a drain at the other end
of the trough to control water depth. The standpipe must
be screened to prevent fry from escaping, and should be
inspected and cleaned often to avoid clogging and trough
overflows. Provisions should be made for emergency
generators to supply power in case of electricity outages.

Water Quality
Proper water conditions are essential for successful
fingerling production. A clean water source such as a well
is best for hatching eggs, since risk of disease is minimized
if there are no fish or fouling organisms in the water sup-
ply. However, water from many wells and other sources
must often be aerated and warmed prior to filling
hatchery troughs.
Water temperature should be between 750 and 820 F
(24 and 28 C). Hatching occurs in about 6 days at an
optimal temperature of about 80 F for artificial incuba-
tion. Temperatures from 68 o to 86 F (20 to 30 C) can
be tolerated, but lower temperatures increase the hatching


time and might increase disease problems.
Oxygen levels in troughs must be maintained at a
minimum of 6 parts per million (ppm) to supply adequate
amounts to eggs and fry. Total hardness and total
alkalinity should exceed 20 ppm, and the pH should be
between 6.5 and 8.5 for best results. Acidic or soft water
can be corrected by adding limestone or a buffer on a
case-by-case basis.
Further information on water quality is contained in
Florida Extension Circular 715, "Management of Water
Quality for Fish."

Disease Control
Eggs and fry are highly susceptible to bacterial and
fungal infections. Proper treatment requires complete
familiarity with identification of pathogens and use of
chemicals; additional references and diagnostic
laboratories should be consulted for greater details of
material presented here.
The best disease control is prevention by maintaining
adequate aeration, clean water, and temperatures below
82 F (28 C). Equipment should be cleaned frequently
and disinfected to prevent contamination. Eggs should
be checked daily and any debris, shells, and dead or badly
infected eggs removed with a siphon. Bacterial and fungal
infections often appear as cloudy or cottonlike patches
on eggs and should be treated or isolated when first
detected. Chemical treatment may be successful provided
standard recommended doses are not exceeded. Con-
version tables and proper dosages are available in Plumb
et al. (Southern Coop. Ser. No. 225) and Jensen et al.
(Alabama Coop. Ext. Service Circ. ANR-327).
Bacterial outbreaks can be treated by dips or baths in
terramycin (20 ppm), potassium permanganate (3 ppm),
and other drugs. Eggs with fungal infections can be
treated with formalin (100 ppm for 15 minutes) and may
require simultaneous treatment for bacterial growth. For-
malin should never be used with eggs that are near hatch-
ing. Sanitary conditions maintained in the hatchery may
provide added protection from parasites, channel catfish
virus disease (CCVD), and other infections following
hatching.


Fry Management

Handling Fry
Within one to two days of hatching young sac fry
should be acclimated and transferred from the hatching
troughs to rearing tanks, troughs, vats, screened boxes,
or other facilities using a /2 inch or larger siphon or small
net. After hatching, sac fry swim through the egg baskets
and school together in tight clusters near the bottom. Fry
rely on their large yolks and do not begin to feed until










they become darkly pigmented and absorb their yolk sacs
(about three to four days after hatching). Rearing tanks
must have clean, well-aerated running water and should
be scrubbed and sterilized with a mild chlorine (1 tea-
spoon of household bleach per gallon of water for five
minutes) or formalin (1 part: 4000 parts water) solution
between each crop of fry. Be sure to thoroughly wash
chlorine or other antiseptics off equipment with three or
more rinses in fresh water. Keep young fry away from
bright lights to reduce stress.

Counting Fry
The number of fry transferred from hatching troughs
to temporary rearing chambers can be estimated using
volumetric or gravimetric methods. It is best to combine
clutches of fry that are about the same age in order to
facilitate counting and to keep equally-sized individuals
together. Estimate the number of fry by water displace-
ment in a household measuring cup or graduated cylinder
prior to introducing them into rearing tanks. A rough
estimate is that about 1,000 one-day-old fry will displace
one ounce of water. A more accurate approximation can
be obtained by counting a small sample of 200-300 fry,
measuring the amount of water that they displace, and
then recording the water level change for all fry. The total


Counting fry by water displacement in a graduated cylinder.


number of fry can then be estimated by the following
formula:


Total
Number =
of Fry


Total number in sample X change in
water level with all fry
Change in water level of sample


EXAMPLE:
(1) A sample of 300 fry displaces water level in a 100
ml graduated cylinder from 50 to 62 ml.
(2) The entire clutch of fry displaces the water level
in a larger container from 500 to 900 ml.
(3) The total number of fry can then be calculated:
TotalNumber = 300 x (900 500)
62 50
= 10,000



Estimating fry number by weight is similar to the above
method. Water in a container is weighed, a sample of fry
is counted and then added to the water, and the increase
in weight is recorded. The total weight of all fry is then
measured and the total number of fry can be approx-
imated using the same general formula as that for
volumetric counting. Estimating the number of fry by
these methods allows the producer to determine ap-
propriate stocking densities and feed allotments when
moving fry to facilities for growing fingerlings. In addi-
tion, the number of fingerlings graded into various size
classes must be counted when sold or transported to
markets (see "Grading Fingerlings").


Feeding Fry
Fry begin swimming up to the surface of the water and
around the edges of the tank when they are ready to feed.
Small ground pellets, "crumbles," and granules ("fry
starter") are typically used for feeding fry. A
nutritionally-complete, high protein diet is recommended
for maximum growth (ideal feed contains at least 45-50%
crude protein, of which 60% of the protein should be fish
meal). Initial food particles should be 0.35-0.60 mm
(standard seive gauge 30-40). Small particle feeds have
greater surface areas and may lose valuable nutrients by
leaching and erosion during processing or storage. Sup-
plemental vitamins, minerals, or other nutrients may be
required to fortify the diet. Young fry should be fed often
with enough meal that will be eaten in 15 to 20 minutes.
Avoid overfeeding and distribute meal over the water
surface using a screen or fine strainer. Since fry grow
rapidly the pellet size and amount of food must be
gradually increased (Table 3).










Table 3. Optimum feed particle size for catfish fry and
fingerlings.
Fish Size Particle Size
(inches) (millimeters)
< 0.5 0.42-0.60
0.5-1.0 0.60-0.84
1.0-1.5 0.84-1.19
1.5-2.5 1.19-1.68
2.5-4.0 1.68-2.38
4.0-6.0 2.38-3.36
> 6.0 3/16 inch pellet


Raising Fingerlings

Pond Preparation and Pest Control
Catfish can be grown to fingerling sizes, suitable for
marketing as seed stock, in a variety of rearing facilities
that include ponds, troughs, and raceways. In general,
many of the precautions and techniques of raising food-
sized fish in production ponds also apply to the methods
used in rearing fingerlings. To be successful, a producer
must maintain optimal water quality by practicing routine
procedures such as the following: (1) take care to exclude
all wild fish, predatory aquatic insects, tadpoles, and
other potentially noxious animals from rearing areas; (2)
monitor water chemistry frequently and take appropriate
remedial measures to control improper levels of dissolved
oxygen, pollutants, pH, sediments, etc.; (3) prevent
excessive growth of aquatic weeds and avoid overfeeding
and other sources of organic waste; (4) record water
temperature often and be especially cautious to avoid
heat-related stress; and (5) use appropriate drugs and
chemicals, following local regulations and suggested pro-
cedures, to contain or eliminate diseases and parasites on-
ly after conventional preventive measures have failed.
Diseases are a constant threat to cultivated catfish and
are of special concern to fingerling producers. Preven-
tion of serious diseases requires good management by
minimizing stressful conditions such as unfavorable en-
vironmental factors, improper handling, and poor nutri-
tion. Channel catfish virus disease (CCVD) poses a par-
ticular threat to fingerlings and requires special
consideration.
Channel catfish virus inflicts fingerlings less than 6
inches long and is highly contagious and usually fatal.
Symptoms include hemorrhaging at the base of the fins
and in the skin, distended abdomen filled with a clear,
yellowish fluid, exophthalmia (pop-eye), pale gills, and
erratic swimming behavior (these symptoms should not
be considered as exclusive evidence for the disease).
CCVD occurs primarily during hot weather when water
temperatures exceed 68 oF (20 C), and develops more
rapidly and results in greater losses as temperature in-
creases. Very few effective treatments are available for


viral diseases of fishes, hence CCVD must be prevented
to avoid losses of entire stocks. A diagnostic laboratory
or fisheries specialist should be consulted to verify
suspected cases of the disease. The following measures
are imperative to prevent outbreaks of CCVD:

1. Prevent stress from low oxygen.
2. Do not move fingerlings when water temperature is
over 85 F (29 o C). If fingerlings must be moved dur-
ing the summer, they should be handled gently and
as briefly as possible (however, do not move fish if
CCVD is suspected).
3. Prevent poor water quality from developing in rear-
ing facilities by avoiding excessive buildups of am-
monia, organic debris, and other toxic substances.
4. Avoid large outbreaks of external parasites on
fingerlings by using prophylactic measures. Do not
treat for external parasites if CCVD is already
present.
5. Avoid very high stocking densities (i.e., greater than
150,000 fry per acre).
6. Do not use nets or other equipment that have been
used in ponds or tanks where there has been a recent
CCVD outbreak, without first disinfecting in
Roccal (1,000 ppm for 5 minutes) or HTH (calcium
hypochlorite) at 40 ppm for 5 minutes.

Stocking Fry
The optimal number of fry to stock depends on the
management intensity, type of rearing facility, feeding
schedules, water temperature, and other factors. Initial
stocking density generally depends on the final size of
fingerlings desired at harvest. Growth rate is determined
by interactions between quantity of food consumed,
stocking density, and water temperature, hence size of
fingerlings at harvest may be highly variable (Table 4).

Table 4. Estimated fingerling size after 120- to 150-
day growing season under different stocking
regimes. Optimal management techniques are
required to attain these yields.
Fry Stocking Density Average Length
(fish per acre) (inches)
10,000 7-10
30,000 6-8
53,000 5-7
73,000 4-6
95,000 3-5
120,000 3-5
140,000 3-4
200,000 2-3
300,000 1-2
500,000 about 1










At very high stocking densities, it is unwise to offer maxi-
mum amounts of food because water quality can
deteriorate rapidly.
Fry should be stocked into rearing areas during the cool
evening or morning hours by slowly conditioning them
to the water, using aerated buckets or other containers
to transport them. Fry stocked in ponds may survive bet-
ter and can be more easily fed if they are provided with
shelters such as wooden or plastic boxes around which
they congregate. Some producers prefer to give added
protection to fry by temporarily holding them in screened
boxes within ponds until they reach slightly larger sizes.
To determine optimal stocking rate, divide the an-
ticipated total weight produced per acre by the weight of
the average sized fingerling desired for harvest. Since a
maximum feeding rate of 100 pounds of feed per acre
per day should generally not be exceeded, a maximum
of about 3,500 pounds of fish per acre can be attained
at harvest time. The following examples illustrate sam-
ple calculations required to estimate common stocking
rates:

Example 1. If 0.06 pound average fish (6 inches) are
desired for harvest, then the required
stocking per acre is:

Stocking rate/acre = Total pounds of fish/acre
Desired average weight
of fish (lbs)
3,500 pounds/acre
0.06 lb average weight
= 53,333 fish/acre

Example 2. If 0.02 pound average fish (4 inches) are
desired for harvest, then:
3,500 pounds/acre
Stocking rate/acre = 3 0
0.02 lb average weight
= 175,000 fish/acre


Feeding Fingerlings
Small fingerlings have large appetites and should be
fed nutritionally-balanced diets at least two to six times
daily for the first two weeks. As fingerlings grow, they
can be fed larger pellets (Table 3), but they begin to eat
less food in relation to their size. "Crumbles" or crushed
pellets can be replaced with '/1, inch pellets of at least
36% protein when fingerlings are four to six weeks old.
Extruded or floating pellets are preferred by most cat-
fish producers because the fish can be seen as they eat.
Savings in food costs of 10-15% can sometimes be re-
alized by using a combination of about 85% sinking and
15% floating pellets. However, feed loss must be avoided
by distributing pellets near areas where fingerlings con-
gregate and by placing sinking pellets over areas of hard


bottom and free of rooted vegetation. Shelters and con-
tainers can be used to attract fingerlings to desired feeding
areas.
The amount to feed is determined by fingerling size,
stocking density, and water temperature. Most suggested
feed schedules are rough guides and the manager must
use good judgement in estimating a proper allowance.
Standard recommended feeding rates are presented in
Table 5. Actual feed allowances, usually expressed as
pounds/acre/day, will vary widely but generally should
not exceed 35 pounds/acre/day during summer to pre-
vent oxygen shortages. In cold weather, fingerlings should
be fed 1.5%0 of their estimated weight three to six days
per week. Fingerlings fed from November to March in
Florida will probably gain at least 25-40% of their initial
body weight. Fish weight should be estimated weekly, and
perhaps daily, in order to make accurate adjustments of
feeding percentages. At very high stocking densities and
high water temperatures it is unwise to offer maximum
amounts of food because water quality can deteriorate
rapidly.

Table 5. Suggested feeding frequencies and allowances
for fry and fingerlings at different temperatures.
Feeding
Water Allowance Feeding
Temperature (% body Frequency
(0 F) weight/day)
> 87 2 2 times/day
80-86 6 4 times/day
68-79 3 2 times/day
58-67 2 1 time/day
50-57 2 alternate days
< 50 1 every 3-4 days

Harvesting
When fingerlings are 3-10 inches long they can be
harvested for marketing as seed stock. Harvesting can be
done year-round but is discouraged when water
temperature is over 850 F (290 C). Harvest during cool
morning hours and handle fingerlings as briefly as possi-
ble during warm months to lessen stress.
Fingerlings grown in ponds can be removed by seining
with a 100-200 foot net. About half of the seine should
be stretched and staked in the water, parallel to the shore
and about 50 feet from the bank near a hard-bottomed
feeding area free of debris. Excess netting at the ends of
the seine can be rolled or folded and hauling ropes ex-
tended from the seine to stakes on the shoreline. Finger-
lings should then be fed in the trapping area for a few
days to accustom them to the net. Harvesting is done by
pulling the net toward the shore and around the finger-
lings when they are actively feeding. Fish should then be
dipped from the seine and loaded directly into grading
vats or hauling equipment.



























Box-type grader for catfish fingerlings.


are first graded into uniform size classes. At least three
samples with a minimum of 200 fish each are counted
and weighed before, midway, and at the end of loading.
The weight per thousand fingerlings is estimated from the
samples. All of the fingerlings are then weighed as they
are loaded into the transport tank, and the total number
of fish is estimated from the average weight of the in-
dividual samples. For example, three samples of 200 fish
each might weigh 10, 11, and 12 ounces, or a total of 33
ounces (2.06 pounds) for 600 fish. If a total of 500 pounds
of fish is loaded into the tank, then the number can be
estimated as follows:



Sample Number = 600 fish
Sample Weight = 2.06 pounds
Total Weight = 500 pounds


The sharp pectoral and dorsal spines of fingerlings can
become tangled in nets and cause undue stress. Entangle-
ment can be reduced by dipping nylon seines and nets
in an asphalt-base net coat prior to harvesting, or by us-
ing polyethylene nets. Partial grading of different-sized
fingerlings can be done in the pond by using seines with
different mesh sizes (Table 6).
Some producers use traps to successfully harvest
fingerlings from ponds. Harvesting fish from raceways,
troughs, cages, and other facilities can be conveniently
accomplished using catchment basins, dip nets, and other
equipment.

Table 6. Seine mesh sizes and grader bar widths used
for separating size classes of fingerlings.
Smallest Fish Seine Mesh Grader Bar Spacing
Length (inches) (inches) inches millimeters
3 1/4 27/64 10.7
4 3/8 32/64 12.7
5 1/2 40/64 15.9
6-7 3/4 48/64 19.1
8-10 1 1 25.4

Grading
Fingerlings must be graded and counted into different
sizes before shipment. Grading is most easily done in
holding tanks or vats by using specially constructed boxes.
Box-type graders usually have aluminum or stainless steel
rods that are spaced at appropriate widths and retain cer-
tain size fish but allow smaller ones to pass through.
Recommended bar widths for grading fingerlings are
given in Table 6.

Counting
Fingerlings may be sold by weight, length, or a com-
bination of both. Counting them is more accurate if they


Total Number
of Fish


Number of fish in samples
X total weight of all fish
Weight of fish in samples
600 fish X 500 pounds
2.06 pounds
= 145,631 fish


The average weight in pounds of each 1,000 fish can then
be calculated:
Total Weight = 500 pounds
Total Number = 145,631


Pounds/1,000
fish


Total weight (pounds) X 1,000
Total number of fish
500 pounds X 1,000
145,631
= 3.4 pounds/1,000 fish


Tank with aerator for hauling fingerlings.









Transporting Fingerlings
Healthy fingerlings can be transported alive for
relatively long distances with proper equipment and
careful handling. Hauling tanks vary in design but should
always be well insulated and equipped with aerators or
agitators and filled with clean, fresh water. When using
tanks deeper than 30 inches or hauling crowded fish loads
it is necessary to use efficient aerators and to have bot-
tled oxygen for emergency backup. Oxygen should be
released through porous diffusers as small bubbles into
the water.
The number of fingerlings that can be safely hauled
depends on the tank volume, efficiency of the aeration
equipment, length of haul, water temperature, and size
and condition of the fish. Fingerlings should not be fed
for 12 hours prior to long hauls to prevent excessive
buildups of toxic wastes. Oxygen should be maintained
at levels greater than 4-5 ppm and the temperature should
be kept cool if possible (about 60 0 to 65 F). Some pro-
ducers add salt (0.4-0.8 pounds/100 gallons of water) to
transport tanks to reduce stress. Suggested loading den-
sities are presented in Table 7. If fingerlings are
transported in conventional hauling equipment, be sure
to keep them out of the agitator or aerator by screening
all intakes with '/6 inch mesh.


Table 7 Recommended loading densities for hauling
fingerlings. Densities are for water temperature
at 650 F and ideal aeration; reduce numbers
by 25% for each 10 o F rise in temperature.
Transport Time (hours)
Number of Fish 8 hrs 12 hrs 16 hrs
per pound
Load Density
(pounds fish/gallon water)
1 6.3 5.6 4.8
2 5.9 4.8 3.5
4 5.0 4.1 3.0
50 3.5 2.5 2.1
125 3.0 2.2 1.8
250 2.2 1.8 1.5
500 1.8 1.7 1.3
1,000 1.3 1.0 0.7
10,000 0.2 0.2 0.2


Catfish fry and small fingerlings can be shipped in 3-mil
polyethylene bags for short distances. Bags should have
four corners to prevent fish from congregating and suf-
focating in collapsed corners. Bags are doubled and par-
tially filled with water before placing fry in them, then
filled with oxygen (in a volume ratio of 3 units oxygen:
1 unit water) and securely tied with rubber bands or
string.


RAISING FOOD FISH

Rearing Facilities

Pond Construction
Pond culture is the most common type and often the
most productive way to raise catfish for marketing as
food. The number, size, depth, and shape of ponds
suitable for a given area are often limited by the local
topography, soil type, and available water supplies. In
areas with moderate topographical relief and nonporous
soils, embankment or hill ponds are often constructed by
building dams or earthen dikes across streams or runoff
basins. Areas with flat terrain or porous soils are generally
more suitable for leveed or excavated ponds, constructed
by cutting basins into the water table. In most states where
catfish are commercially produced, good conditions
generally exist for embankment and/or excavated ponds
ranging in size from about 1 to 20 acres or more. In
Florida, however, prevailing geological conditions are
generally not as suitable for conventional pond types used
for rearing catfish.
There are three relatively distinct geographical regions
in Florida insofar as pond construction and management
is concerned. These regions are west Florida (the panhan-
dle east to about Monticello), north Florida (north of
Ocala), and central and south Florida (south of Ocala).
These rough divisions correspond to general features of
the topography, soil types, water availability, and natural
fertility, but it should be realized that considerable local
variation exists throughout the state. Limited areas of the
panhandle have relatively impermeable hardpan clay soils
that support embankment ponds, which are currently the
most productive for raising catfish in the state. Many
areas of peninsular Florida have widely-fluctuating water
tables and relatively porous substrates and are not suitable
for embankment ponds; standing fresh waters in these
areas are generally in the form of natural solution lakes,
swamps, and excavated or leveed ponds. The diversity
of soil types and vegetation in peninsular Florida results
in considerable variation between sites with respect to
nutrient availability and productivity.
Because of the diversity of geological and climatic con-
ditions throughout the state, it is impossible to provide
uniform guidelines for pond construction in Florida.
Before attempting to construct a pond, one should make
a careful assessment of the topography, soil, water
availability and chemistry, nutrient content, and other
physical features of the proposed site to determine the
most appropriate type of pond for the area. In general,
traditional embankment ponds formed by damming
streams or runoff areas in sloping valleys, ravines, or
other hilly terrains are possible mainly in northwest
Florida. In other regions of the state, ponds that are most
promising for catfish culture would be of the excavated









Transporting Fingerlings
Healthy fingerlings can be transported alive for
relatively long distances with proper equipment and
careful handling. Hauling tanks vary in design but should
always be well insulated and equipped with aerators or
agitators and filled with clean, fresh water. When using
tanks deeper than 30 inches or hauling crowded fish loads
it is necessary to use efficient aerators and to have bot-
tled oxygen for emergency backup. Oxygen should be
released through porous diffusers as small bubbles into
the water.
The number of fingerlings that can be safely hauled
depends on the tank volume, efficiency of the aeration
equipment, length of haul, water temperature, and size
and condition of the fish. Fingerlings should not be fed
for 12 hours prior to long hauls to prevent excessive
buildups of toxic wastes. Oxygen should be maintained
at levels greater than 4-5 ppm and the temperature should
be kept cool if possible (about 60 0 to 65 F). Some pro-
ducers add salt (0.4-0.8 pounds/100 gallons of water) to
transport tanks to reduce stress. Suggested loading den-
sities are presented in Table 7. If fingerlings are
transported in conventional hauling equipment, be sure
to keep them out of the agitator or aerator by screening
all intakes with '/6 inch mesh.


Table 7 Recommended loading densities for hauling
fingerlings. Densities are for water temperature
at 650 F and ideal aeration; reduce numbers
by 25% for each 10 o F rise in temperature.
Transport Time (hours)
Number of Fish 8 hrs 12 hrs 16 hrs
per pound
Load Density
(pounds fish/gallon water)
1 6.3 5.6 4.8
2 5.9 4.8 3.5
4 5.0 4.1 3.0
50 3.5 2.5 2.1
125 3.0 2.2 1.8
250 2.2 1.8 1.5
500 1.8 1.7 1.3
1,000 1.3 1.0 0.7
10,000 0.2 0.2 0.2


Catfish fry and small fingerlings can be shipped in 3-mil
polyethylene bags for short distances. Bags should have
four corners to prevent fish from congregating and suf-
focating in collapsed corners. Bags are doubled and par-
tially filled with water before placing fry in them, then
filled with oxygen (in a volume ratio of 3 units oxygen:
1 unit water) and securely tied with rubber bands or
string.


RAISING FOOD FISH

Rearing Facilities

Pond Construction
Pond culture is the most common type and often the
most productive way to raise catfish for marketing as
food. The number, size, depth, and shape of ponds
suitable for a given area are often limited by the local
topography, soil type, and available water supplies. In
areas with moderate topographical relief and nonporous
soils, embankment or hill ponds are often constructed by
building dams or earthen dikes across streams or runoff
basins. Areas with flat terrain or porous soils are generally
more suitable for leveed or excavated ponds, constructed
by cutting basins into the water table. In most states where
catfish are commercially produced, good conditions
generally exist for embankment and/or excavated ponds
ranging in size from about 1 to 20 acres or more. In
Florida, however, prevailing geological conditions are
generally not as suitable for conventional pond types used
for rearing catfish.
There are three relatively distinct geographical regions
in Florida insofar as pond construction and management
is concerned. These regions are west Florida (the panhan-
dle east to about Monticello), north Florida (north of
Ocala), and central and south Florida (south of Ocala).
These rough divisions correspond to general features of
the topography, soil types, water availability, and natural
fertility, but it should be realized that considerable local
variation exists throughout the state. Limited areas of the
panhandle have relatively impermeable hardpan clay soils
that support embankment ponds, which are currently the
most productive for raising catfish in the state. Many
areas of peninsular Florida have widely-fluctuating water
tables and relatively porous substrates and are not suitable
for embankment ponds; standing fresh waters in these
areas are generally in the form of natural solution lakes,
swamps, and excavated or leveed ponds. The diversity
of soil types and vegetation in peninsular Florida results
in considerable variation between sites with respect to
nutrient availability and productivity.
Because of the diversity of geological and climatic con-
ditions throughout the state, it is impossible to provide
uniform guidelines for pond construction in Florida.
Before attempting to construct a pond, one should make
a careful assessment of the topography, soil, water
availability and chemistry, nutrient content, and other
physical features of the proposed site to determine the
most appropriate type of pond for the area. In general,
traditional embankment ponds formed by damming
streams or runoff areas in sloping valleys, ravines, or
other hilly terrains are possible mainly in northwest
Florida. In other regions of the state, ponds that are most
promising for catfish culture would be of the excavated










or leveed type. Your Soil Conservation Service (SCS)
District Conservationist and other specialists should be
consulted for resource analysis, planning assistance, and
standards, regulations, and specifications pertaining to
pond construction.

A few general recommendations should be followed
when considering building a catfish pond for commer-
cial production. Because of weed control, high water
temperatures, and other management problems, large
ponds would generally be more difficult to use for cat-
fish culture in Florida. Consequently, ponds in the '/,o- /4
acre size range are suggested for use. The depth of the
pond should be planned so that there will be a minimum
water depth of 4-6 feet during the driest time (survey in
April or May). This may mean that a basin depth of 8-12
feet is needed in regions where water levels fluctuate
widely. Much greater depths are discouraged because of
the danger of oxygen depletions during hot weather.
Ponds should have gently sloping basins and well-
vegetated shorelines to prevent erosion. If possible, pro-
visions should be made to allow for complete draining
of the pond for harvesting and prior to stocking.
Harvesting will also be easier if there are no stumps, logs,
and debris present. The pond must have an acceptable
spillway and overflow drain if runoff discharge is ex-
pected. The overflow pipe can be fitted with a sleeve of
larger pipe and the spillway should be wide enough so
that the maximum flow is less than 3 inches deep in order
to prevent fish from escaping. In extremely permeable
soils, plastic or rubber pond sealants or liners may be used
to eliminate water loss from seepage, but use of such
sealers can be relatively expensive for larger ponds in
terms of installment costs for labor and materials. Some
ponds and natural lakes, particularly in central and
northern Florida, are poor in nutrients and have relatively
low productivity. Artificial fertilization of these waters
to improve productivity and enhance food availability is


Raceway culture system.


generally not recommended, due to associated problems
with weed control and oxygen levels. Feeding catfish with
prepared feeds is strongly encouraged to promote optimal
growth and eliminate the need for supplemental fertiliza-
tion of a pond.

Alternative Facilities
Because of various contraints that limit the efficiency
and desirability of constructing ponds in many areas of
Florida, use of other facilities may provide great poten-
tial for raising catfish in certain regions. Raceway systems
have been successfully used by some producers, although
they require more intensive management than pond
culture. Raceways consist of series of long, narrow
earthen or concrete channels through which there is a
continuous flow of water. They may be either open
systems, in which water flows through the raceways and
waste treatment facility without recycling, or closed
systems, in which water is recycled through an auxiliary
storage reservoir, the raceway, and the waste treatment
pool. Raceways require a ubiquitous supply of high-
quality water. Construction of raceway systems should
be done under the supervision of experienced profes-
sionals, due to their complex design and operation. They
should be trapezoidal or parabolic in cross section, with
bottom widths of 4-15 feet and a grade of 1-3 feet per
100 linear feet (1-3% slope). Each section should be no
more than 100 feet long (sections may be constructed in
series by installing earth or concrete check dams or
bulkheads at the lower end of each section). Water depth
should be about 3 feet at the upper end and 4 feet at the
lower end of each section. A settling basin (lagoon) is built
below the last section of a raceway to collect organic
wastes. Size and depth of the lagoon must be determin-
ed after considering the number of sections to be installed
and the size of the water reservoir. The lagoon should
be wider and deeper than the raceway sections so that
water movement will be slow enough to allow suspended
wastes to settle, and should be drained and cleaned after
each crop of fish is harvested.
Cage culture of catfish represents a second potentially
good alternative to pond culture in Florida but still lacks
the technology that provides all growers with consistent
results. Some of the advantages to this method are: (1)
cages can be put in many types of water, such as ponds,
lakes, canals, borrow pits, etc., some of which might not
otherwise be especially suitable for aquaculture; (2) cages
allow for a combination of cultures in ponds, such as rais-
ing catfish in cages with bass and bream in open water;
(3) cages can be used to rear small fish to large enough
sizes to escape predation before releasing into a pond;
and (4) cages allow for easy and complete harvest, by
either removing fish all at once or periodically. The ma-
jor disadvantages of using cages are that (1) fish are under

























Floating cages can hold catfish forgrowout where tradition-
al pond culture is not practiced.

a great deal of stress and may succumb to diseases and
parasites more easily if they are crowded; (2) treatments
for diseases are more difficult to administer; (3) feeding
management of caged fish must be relatively intense; and
(4) poaching becomes easier.
Cages are made of vinyl-coated wire, polyethylene,
nylon, or other corrosion-resistant mesh on PVC, wood,
or metal frames and are suspended freely in the water
column. Many cage designs and sizes have been used, but
most are 1-2 cubic yards (0.8-1.5 cu. meters) and made
of 1/2 inch or larger mesh. Cages may be either cylindrical
or rectangular, but the design and placement in the water
must allow for a depth of at least 3 feet of water in the
cage. Tops of cages are usually made of a solid opaque
material, such as plywood or aluminum sheeting, and
must have a feeding ring. The feeding ring is an enclosed
cylinder of wood, mesh ('/s inch), or other suitable
material attached to the top of the cage and extending
about 4 inches above the top and 12-16 inches beneath
the water surface. Producers generally give caged fish
floating feeds, which should be placed within the feeding
ring to insure that food does not pass outside of the cage.
Cages may be attached to metal or wooden stakes or piers
in an open body of water, or they can be floated using
styrofoam pontoons, plastic bottles, or other bouyant
materials. They should be floated with the lid about 3-6
inches above the water and with at least 12-36 inches be-
tween the cage and the bottom of the pond or lake, so
that fish wastes are adequately dispersed. Cages should
be placed at least 10 feet apart. It is important to fre-
quently check caged fish for signs of stress, infections,
and parasites and to treat them accordingly if necessary.
Clean cages periodically to remove growths of filamen-
tous algae.

Water Quality

As with hatching fry, the rearing of food-sized fish
depends vitally on good water quality. The most impor-


tant water quality characteristics include dissolved ox-
ygen, temperature, pH, total alkalinity, and total hard-
ness. Standard instruments and kits for measuring these
parameters are available through commercial suppliers.
Water quality should be checked once per day around
sunrise.
The pH of water to be used for catfish culture should
be between 6.5 and 8.5. Water that is not in this range
can be treated with effective buffering compounds, such
as agricultural lime to increase pH, and hydrochloric acid
or aluminum sulfate to decrease pH. If the total alkalinity
or total hardness of pond water is below 20 mg/liter add
lime during the late fall or early winter. Ponds in Florida
near limestone or similar sediments ordinarily should re-
quire few corrections for total alkalinity and hardness.
Growth of catfish is greatest at water temperatures of
80 -85 F (27 -29 o C) and is least at temperatures below
60 oF (16 C). This translates into a maximum growing
season of 200 or more days per year in many areas of
Florida. Catfish can tolerate the normal low water
temperatures in the state, but their survival, growth, and
food conversion may be jeopardized by combinations of
high water temperature, low dissolved oxygen, high stock-
ing density, disease, and other chemical and biological
interactions. Consequently, Florida farmers should make
a special effort to carefully monitor summer water quality
and take remedial measures if poor water conditions
develop that may adversely affect fish health.
Dissolved oxygen concentrations should be measured
frequently and maintained above 4-5 ppm. Oxygen levels
fluctuate widely and may be influenced by factors such
as algal blooms and plant growth, wind, cloud cover,
amount of decaying organic sediments, and temperature.
Oxygen in the water is lowest at sunrise and can be low
on overcast or rainy days, due to respiration by algae,
bacteria, fish, and other organisms, and the lack of ox-
ygen production by algae and aquatic plants. Algae are
the main producers and users of oxygen. Moderate wind
action helps to aerate water near the surface, but strong
winds may stir up oxygen-deficient sediments and cause
low oxygen levels throughout the water. To reduce stress
and physical harm to fish from low oxygen, a successful
producer must measure oxygen often, take preventive
measures, and have emergency aeration equipment
available. A variety of aeration devices are on the market
or can be built with relative ease, ranging from tractor-
propelled paddlewheel aerators to floating, electrically-
powered models. Pond owners can further reduce prob-
lems associated with low oxygen by aerating incoming
water if necessary and maintaining a proper algal bloom
by not overfeeding the fish.
Water should never contain pollutants or toxicants.
Certain metals, pesticides, and other compounds can be
extremely toxic to fish. Galvanized equipment may release
enough zinc to kill catfish, and copper toxicity may result










from use of copper-based pipes and other materials. It
is best to use plastic pipes, coated screens, and other non-
metal equipment whenever possible. Catfish are very sen-
sitive to chlorine, so treated municipal water (usually con-
taining < 2 ppm chlorine) should only be used if first
dechlorinated with 7 ppm sodium thiosulfate to 1 ppm
chlorine. Pesticides must always be used with extreme
caution.
Salinity concentration of water is of special concern
to farmers drawing their water supplies from coastal
areas. Channel catfish can withstand salt in small
amounts, but salinity should be checked if high levels are
suspected. Channel catfish can tolerate salinities up to
12 parts per thousand (o/oo), but they will not breed if
the level is over 7 o/oo (full strength sea water is about
30-35 o/oo). Higher salinity levels may result in
physiological stress. Avoid abrupt changes between fresh
and salty water.
Stocking

Catfish can be stocked in the late fall, winter, or early
spring. Summer stocking must be avoided since high
water temperatures and low oxygen in hot weather greatly
increase stress and the possibility of death due to suffoca-
tion, disease, and other factors. If possible, avoid mov-
ing or handling fish in the afternoon and avoid drastic
changes in water temperature. Fingerlings for stocking
should be moved as quickly as possible in well aerated
containers (see "Transporting Fingerlings").
The number of fish to stock depends on many factors,
including water quality, size and efficiency of facilities
and equipment, length of the growing season, feeding
schedule, and size of fish desired for marketing. In
general, fish are stocked according to the surface area
of the water. If fish are not to be fed, stocking densities
in ponds should not exceed 100-200 fish per surface acre.
Fingerlings (4-8 inches) can be stocked in ponds at den-
sities of 1,000-3,000 or more fish per acre and harvested
in one to two seasons if feeding is planned. Raceways can
be successfully stocked with as many as 2,000 fingerlings
per 100 foot section when optimal water conditions ex-
ist. Initial stocking densities of 12 fingerlings per cubic
foot of cage are possible. Regardless of the facilities
used and degree of management intensity, lower stock-
ing densities reduce risk of losses to oxygen shortages,
parasites, and infectious diseases. Fewer fish should be
stocked in waters that may become very hot in the sum-
mer or that have excessive water quality and weed prob-
lems. Higher stocking densities result in smaller fish at
harvest if they are not fed at the same rates as fish
stocked at lower densities. Water quality becomes limiting
at high feeding rates. Prudent managers are aware of the
limits of their facilities, equipment, and water conditions
and stock fish at densities that are appropriate to their
harvest goals.


Acclimating Fingerlings


Before stocking fish in a pond or other rearing area,
adjust the water temperature and other water quality fac-
tors in the fingerling transport tank to match the pond
water. This should be done by gradually transferring
small amounts of water from the pond into the hauling
tank until the tank water temperature equals that of the
pond. Catfish can generally withstand a change of 10
F if the water is tempered over several minutes. For
greater temperature differences, one must be very careful
to slowly equalize water temperatures before moving
fingerlings from the transport tank to the pond. It is best
to adjust water temperature about 1 o F every ten minutes.
Improper acclimation can directly cause fish to die from
temperature shock. If fish are not killed by the shock,
they may be weakened and become more susceptible to
infectious diseases and parasites.


Feeding

Catfish grown at high densities require a nutritionally
complete feed to maximize growth and maintain good
health. Commercially-prepared feeds should contain all
essential nutrients and consist of 32-40% protein.
Floating pellets or a combination of sinking and floating
pellets are desirable in most situations. Fingerlings less
than 6 inches should be given pellets smaller than V'/6 inch
(Table 3). Fish over V pound can be fed /,6-'/s inch
pellets. Food must be stored in cool, dry areas to reduce
mold and loss of nutrients that may result from excessive
heat. Maximum storage time for feeds is usually 4 to 6
weeks.
Food should be distributed at the same locations and
at the same time once or twice each day. Do not feed at
night, since oxygen requirements of fish increase after
feeding and oxygen levels in the water normally decrease
at this time. The mid-morning or early afternoon hours
are good times to feed. Make sure that food is accessible
to all fish by distributing it over broad areas and along
upwind shorelines. Do not overfeed since uneaten food
can foul the water. Conversely, avoid underfeeding
because it can result in poor health, lower growth rates,
and greater size variation of harvested fish. Observe
feeding activity to make sure that all food is consumed
in about 10 to 20 minutes.
Recommended feeding allowances for catfish are
based on a percentage of the body weight or standing crop
weight. Since the conversion efficiency of food is in-
fluenced by many factors, such as stocking density, water
quality, temperature, and fish size, suggested feeding
rates are only approximate guides and the producer must
exercise good judgement in establishing a feeding pro-
gram. Ideally, fish cultured for food should be fed 1-3%










from use of copper-based pipes and other materials. It
is best to use plastic pipes, coated screens, and other non-
metal equipment whenever possible. Catfish are very sen-
sitive to chlorine, so treated municipal water (usually con-
taining < 2 ppm chlorine) should only be used if first
dechlorinated with 7 ppm sodium thiosulfate to 1 ppm
chlorine. Pesticides must always be used with extreme
caution.
Salinity concentration of water is of special concern
to farmers drawing their water supplies from coastal
areas. Channel catfish can withstand salt in small
amounts, but salinity should be checked if high levels are
suspected. Channel catfish can tolerate salinities up to
12 parts per thousand (o/oo), but they will not breed if
the level is over 7 o/oo (full strength sea water is about
30-35 o/oo). Higher salinity levels may result in
physiological stress. Avoid abrupt changes between fresh
and salty water.
Stocking

Catfish can be stocked in the late fall, winter, or early
spring. Summer stocking must be avoided since high
water temperatures and low oxygen in hot weather greatly
increase stress and the possibility of death due to suffoca-
tion, disease, and other factors. If possible, avoid mov-
ing or handling fish in the afternoon and avoid drastic
changes in water temperature. Fingerlings for stocking
should be moved as quickly as possible in well aerated
containers (see "Transporting Fingerlings").
The number of fish to stock depends on many factors,
including water quality, size and efficiency of facilities
and equipment, length of the growing season, feeding
schedule, and size of fish desired for marketing. In
general, fish are stocked according to the surface area
of the water. If fish are not to be fed, stocking densities
in ponds should not exceed 100-200 fish per surface acre.
Fingerlings (4-8 inches) can be stocked in ponds at den-
sities of 1,000-3,000 or more fish per acre and harvested
in one to two seasons if feeding is planned. Raceways can
be successfully stocked with as many as 2,000 fingerlings
per 100 foot section when optimal water conditions ex-
ist. Initial stocking densities of 12 fingerlings per cubic
foot of cage are possible. Regardless of the facilities
used and degree of management intensity, lower stock-
ing densities reduce risk of losses to oxygen shortages,
parasites, and infectious diseases. Fewer fish should be
stocked in waters that may become very hot in the sum-
mer or that have excessive water quality and weed prob-
lems. Higher stocking densities result in smaller fish at
harvest if they are not fed at the same rates as fish
stocked at lower densities. Water quality becomes limiting
at high feeding rates. Prudent managers are aware of the
limits of their facilities, equipment, and water conditions
and stock fish at densities that are appropriate to their
harvest goals.


Acclimating Fingerlings


Before stocking fish in a pond or other rearing area,
adjust the water temperature and other water quality fac-
tors in the fingerling transport tank to match the pond
water. This should be done by gradually transferring
small amounts of water from the pond into the hauling
tank until the tank water temperature equals that of the
pond. Catfish can generally withstand a change of 10
F if the water is tempered over several minutes. For
greater temperature differences, one must be very careful
to slowly equalize water temperatures before moving
fingerlings from the transport tank to the pond. It is best
to adjust water temperature about 1 o F every ten minutes.
Improper acclimation can directly cause fish to die from
temperature shock. If fish are not killed by the shock,
they may be weakened and become more susceptible to
infectious diseases and parasites.


Feeding

Catfish grown at high densities require a nutritionally
complete feed to maximize growth and maintain good
health. Commercially-prepared feeds should contain all
essential nutrients and consist of 32-40% protein.
Floating pellets or a combination of sinking and floating
pellets are desirable in most situations. Fingerlings less
than 6 inches should be given pellets smaller than V'/6 inch
(Table 3). Fish over V pound can be fed /,6-'/s inch
pellets. Food must be stored in cool, dry areas to reduce
mold and loss of nutrients that may result from excessive
heat. Maximum storage time for feeds is usually 4 to 6
weeks.
Food should be distributed at the same locations and
at the same time once or twice each day. Do not feed at
night, since oxygen requirements of fish increase after
feeding and oxygen levels in the water normally decrease
at this time. The mid-morning or early afternoon hours
are good times to feed. Make sure that food is accessible
to all fish by distributing it over broad areas and along
upwind shorelines. Do not overfeed since uneaten food
can foul the water. Conversely, avoid underfeeding
because it can result in poor health, lower growth rates,
and greater size variation of harvested fish. Observe
feeding activity to make sure that all food is consumed
in about 10 to 20 minutes.
Recommended feeding allowances for catfish are
based on a percentage of the body weight or standing crop
weight. Since the conversion efficiency of food is in-
fluenced by many factors, such as stocking density, water
quality, temperature, and fish size, suggested feeding
rates are only approximate guides and the producer must
exercise good judgement in establishing a feeding pro-
gram. Ideally, fish cultured for food should be fed 1-3%









of their weight at least once per day during the growing
season. Avoid feeding more than 35 pounds per acre per
day in hot weather unless emergency aeration is available.
Feeding allowances must be increased as fish grow. Often
this is done by feeding as much as the fish will eat each
day without leaving excess food floating on the water.
Alternatively, standing crop weight can be estimated
weekly to make appropriate adjustments in the amount
to feed. Estimate crop weight by removing a small sam-
ple of fish, weigh them, and multiply the average weight
of individuals in the sample by the total number of fish
present in the pond. Catfish held over winter should be
fed sinking pellets at about 1 % of their weight every 2
to 3 days when water temperature is below 65 F (18
C). Feeding rates should be reduced by 50% or more dur-
ing very hot weather (water temperature > 85 F) and
on rainy or overcast days. However, if aerators are
available and fish are to be commercially produced, they
should be fed to near satiation. Otherwise, fish will grow
too slowly and return on investment may be too low to
be profitable.


Disease and Pest Control

Catfish are susceptible to a large array of parasites and
disease organisms, as well as being affected by a host of
other plant and animal pests. In many cases, healthy fish
may be resistant to or tolerant of pathogenic organisms
if poor water quality and stressful conditions are minimal.
At the other extreme, some catfish diseases may be highly
contagious and debilitating, including those that directly
cause or contribute to fish death. Other organisms that
are not as intimately associated with the fish, such as
aquatic plants and algae, may contribute directly or in-
directly to poor fish health under adverse conditions.
Because of the variety of diseases and pests that af-
flict catfish, and the variable conditions with which they
may operate, comprehensive and uniformly-applicable
recommendations for their control cannot be made. The
best way to ensure good fish health is to prevent un-
favorable biological conditions from developing, by
carefully monitoring all aspects of an aquaculture system,
and to quickly isolate, identify, and properly treat any
disease or pest problems that arise. A successful manager
becomes familiar with procedures of identifying, prevent-
ing, and/or treating common pest agents and consults
with diagnostic laboratories or specialists when dealing
with unknown problems. Be sure to check local regula-
tions governing the use of chemicals when treating culture
systems with herbicides, pesticides, or medications.
For more detailed information concerning disease iden-
tification and control, consult Florida Extension Circular
716, "Introduction to Fish Parasites and Diseases and
Their Treatment."


Diseases and Parasites

The large number of microscopic diseases and larger
parasites that infect catfish range from those that are
relatively benign and generally not harmful under nor-
mal conditions, to those that cause high mortalities and
have no effective treatments. A good disease management
program consists of precautionary measures to ensure
clean water and healthy environmental conditions. Stress
plays a major role in lowering the resistance of fish to
pathogens, and all factors that may contribute to stressful
conditions must be kept minimal. These include main-
taining adequate oxygen levels, avoiding extreme
temperatures, and handling or moving fish as little as
possible. Chemicals should be used to treat disease out-
breaks only when preventive measures have failed, and
it is essential that appropriate medications be ad-
ministered in proper dosages for treating specific diseases.
For this reason, early detection and correct diagnosis of
disease organisms is imperative if chemotherapy is to be
successful. Some of the behavioral signs that may indicate
a possible disease problem include: (1) a reduction or
cessation of feeding; (2) erratic or lethargic swimming;
(3) schooling just below the surface; or (4) swimming or
scraping against the substrate or objects in the water.
Physical signs that diseased catfish may exhibit include:
(1) excessive mucous production; (2) abnormal colora-
tion (lighter or darker, grayish or bluish, etc.); (3) ero-
sion or fraying of the fins or skin; (4) sores, hemorrhages,
or unusual growths on the body or fins; (5) swollen,
eroded, or pale gills; (6) a swollen abdomen filled with
a cloudy, clear, or bloody fluid; or (7) bulging of the eyes
(exophthalmia). If an infectious disease or parasite out-
break is suspected, quick action should be taken to
isolate, identify, and treat if necessary. Some individuals
and laboratories diagnose fish diseases and recommend
treatments, but unfortunately there are few diagnostic
centers in Florida that provide these services. If diseased
fish are to be sent to a laboratory for inspection, live fish
showing symptoms of the disease should be selected and
shipped alive in cooled bags or packed freshly on ice. Be
sure to notify the laboratory that you are sending fish
and give them any necessary information that may be
helpful in identifying or treating the disease.
Weed Control
Excessive algal blooms or rampant growths of aquatic
plants can be detrimental to catfish by causing oxygen
depletions, and may impede harvesting and reduce
available habitat. In Florida, exotic plants such as
hydrilla, water hyacinth, and water pennywort can
become extremely dense and cause acute problems. A
moderate growth of aquatic weeds generally does not pre-
sent a major problem in catfish ponds, but dense infesta-
tions should be avoided. Weeds that become a nuisance









must be correctly identified and properly controlled us-
ing aquatic herbicides or biological agents. Approved her-
bicides must be used with caution, following specific
recommendations and restrictions stated on the label.
Stocking of hybrid grass carp, Tilapia, or other her-
bivorous fishes to control aquatic weeds should be done
under the supervision of the Florida Game and
Freshwater Fish Commission.
Microscopic algae that are suspended in the water play
a beneficial role in the ecology of a pond by providing
food to invertebrates, eliminating some organic wastes,
and producing oxygen through photosynthesis. A healthy
pond should have a moderate level of planktonic algae
to keep conditions in balance. A proper algal bloom can
be measured by lowering a white object, such as a painted
board, into the water. If the water is not stained from
organic compounds, the board should be visible to about
2-4 feet beneath the surface. If the water is excessively
turbid, has a distinct green color, or a white object can-
not be seen more than a few inches below the surface,
algae could be too dense and there may be a danger of
oxygen depletions at night. Extremely dense growths of
algae are cause for concern. Attached filamentous algae
can often be controlled with triploid grass carp, again
under the supervision of the Florida Game and
Freshwater Fish Commission. Large phytoplankton
blooms are not practically controlled, even with copper
compound herbicides. When excessive blooms occur,
monitor dissolved oxygen frequently and be prepared
with emergency aerators. Also, reduce nutrients that pro-
mote blooms by decreasing the level of feeding.

Other Pests
Florida catfish producers should be aware of other
potential pests that may negatively affect catfish survival
or health. Flying forms of fire ants can kill fish if they


Seine harvesting of larger ponds can be mechanized with a
modest crew.


Seine harvesting of small ponds may be unmechanized with
few people.


are ingested, and should be controlled with appropriate
pesticides. Alligators, some snakes, and other predators
that may eat fish should be kept out of rearing facilities
by using fences or other structures. Farmers that use sur-
face water supplies should prevent wild fish from enter-
ing catfish ponds by screening or filtering all inlet pipes,
streams, etc.

Harvesting and Processing

Catfish stocked as fingerlings in the early spring should
attain at least one pound by the following fall and can
be harvested for consumption. It is generally preferable
to harvest most or all of the stocked crop in a pond in
one season unless larger dressed fish are desired. Many
producers drain their ponds completely following
harvesting and remove organic sediments or allow them
to oxidize.
Harvesting methods vary between farming operations,
depending on the preferences of the producer. Fish are
generally removed by seining, trapping, trot lines, or
hook-and-line angling. Total harvest is most easily
achieved by seining or trapping, especially if the rearing
facility is drained or if fish are concentrated into a
harvesting basin. Seining should be done with a large,
coated net of 1 V2 inch mesh. Catching fish by this method
will be easier if the pond water is lowered or if fish are
coaxed into a harvesting pool or lured near the seine by
feeding them in a prescribed area over several days prior
to harvesting. Catfish can be successfully trapped using
wooden-slat traps, nylon hoop nets, and wire-mesh fun-
nel traps. Hook-and-line angling is generally most
popular in stocked catch-out ponds or fee-fishing areas.
Harvesting for commercial sale of fish should be done
when transport to processing facilities will be immediate.
Do not feed fish for one day prior to harvesting.










Catfish are processed by removing the head and spines,
skinning and eviscerating the fish, washing, and
thoroughly packing them on ice. Properly dressed fish
packed in ice can be held for up to 6 days if they are to
be marketed fresh. Fish to be frozen should be wrapped
in plastic bags or airtight containers and immediately
frozen (frozen fish should not be held for more than a
few months). Before marketing your product, prepare
and taste a representative sample of the fish crop. If any
off-flavor is detected, the fish should not be sold for


public consumption.
Most large-scale producers ship their crops to fish pro-
cessing factories, or have the necessary equipment and
labor to process themselves. There are few commercial
processing facilities in Florida, so producers in the state
should be prepared to process their own crop or possibly
transport them relatively long distances to processing
plants in other southeastern states. Alternatively, depend-
ing on local markets, fish might be sold live at roadside
stands or through fish-out ponds.


Portions of this publication are adapted from Producing Channel Catfish Fingerlings, J. Jensen et al., (Ala. Coop.
Ext. Ser., Circular ANR-327) and Channel Catfish Production in Ponds, J. Jensen, (Ala. Coop. Ext. Ser., Circular
ANR-195). The authors also thank John Jensen for providing photographs used in this publication.


The names of trademarks mentioned in text or photographs are used solely for educational purposes and do not constitute an endorsement
by the University of Florida and do not imply approval to the exclusion of other suitable products.


























































This publication was produced at a cost of $1,677.00, or 84 cents per copy, to provide information on catfish
farming in Florida. 6-2M-88

COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, K.R. Tefertiller,
director, in cooperation with the United States Department of Agriculture, publishes this information to further the purpose of the May 8 and
June 30, 1914 Acts of Congress; and is authorized to provide research, educational information and other services only to individuals and institu-
tions thatfunction without regard to race, color, sex or national origin. Single copies of Extension publications (excluding 4-H and Youth publica-
tions) are available free to Florida residents from County Extension Offices. Information on bulk rates or copies for out-of-state purchasers is
available from C.M. Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesville, Florida 32811. Before publicizing this publication,
editors should contact this address to determine availability.





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