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 Title Page
 Species account
 Culture
 Production systems
 Sources of information and selected...
 Production considerations






Group Title: Florida Cooperative Extension Service circular 1051
Title: Culture of hybrid tilapia
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00049209/00001
 Material Information
Title: Culture of hybrid tilapia a reference profile
Series Title: Circular
Physical Description: 5 p. : ill. ; 28 cm.
Language: English
Creator: Chapman, Frank A
Florida Cooperative Extension Service
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville
Publication Date: 1992
 Subjects
Subject: Fish culture -- United States   ( lcsh )
Tilapia -- Breeding   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 3-4).
Statement of Responsibility: Frank A. Chapman.
General Note: Cover title.
General Note: "July 1992."
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00049209
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 26725401

Table of Contents
    Copyright
        Copyright
    Title Page
        Page i
        Page ii
    Species account
        Page 1
    Culture
        Page 1
    Production systems
        Page 2
    Sources of information and selected references
        Page 3
        Page 4
    Production considerations
        Page 5
        Page 6
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida




/0/

July 1992


Circular 1051


Culture of Hybrid Tilapia

A Reference Profile





Frank A. Chapman
















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


':;-"''- TY OF FLORIDA LIBRARIES














I 0


o SI
SCIENCE
LIBRARY


Frank A. Chapman, Assistant Professor, Fisheries and Aquatic Sciences, University of Florida








Species account

Taxonomy and distribution
Tilapia is a generic term used to designate a
group of commercially important food fish belonging
to the family Cichlidae; the expression is
derived from the African native Bechuana word
"thlape", meaning fish. Cichlids are classified in
the large order Perciformes, and inhabit the fresh
and brackish waters of Africa, the Middle East,
coastal India, Central and South America. True
tilapias, however, are native only to Africa and the
Middle East. Although exotic to the United States,
populations of tilapia are now established in
Arizona, California, Hawaii, Florida, Nevada, North
Carolina, and Texas.

Cichlids are well known as colorful aquarium
fish, and for their ability to adapt to new environ-
ments. Cichlids also display highly organized breed-
ing activities. Because of their complex evolutionary
biology, cichlid classification and naming is one of
confusion and constant modification. Consequently,
the tilapias have recently been classified into three
genera. A distinguishing characteristic between the
genera is the type of care the parents provide to
their young. In the species of the genera
Sarotherodon and Oreochromis the parents will
incubate and protect the young in their mouths
(mouth brooding); in particular the Oreochromis
species are distinguished by maternal mouth-brood-
ing where parental care of the young is performed
primarily by the female. In contrast, incubation of
eggs in a lake or pond bottom built-in "nest" is
exhibited by those species belonging to the genus
Tilapia.

For simplicity purposes, all three genera and
hybrids in this text will be referred to as tilapia.
Important commercial species include: the
Mozambique or Java tilapia (Oreochromis
mossambicus, also known as Tilapia mossambica),
blue tilapia (0. aureus, a.k.a. Tilapia aurea), Nile
tilapia (0. niloticus, a.k.a.Tilapia nilotica), Zanzi-
bar or Wami tilapia (0. hornorum, a.k.a.Tilapia
urolepis), and the redbelly tilapia (O.zilli, a.k.a.
Tilapia zilli).

Culture

History
Tilapia have been raised as food for human con-
sumption for a long time; tilapia farming is believed
to have originated some 2,500 years ago.


Tilapia have also been transplanted to many
countries outside their native range and are now
farmed worldwide. In the United States, commer-
cial culture of tilapia is concentrated in Arizona,
California, and Florida. It is not clear, however,
what species of tilapia are under cultivation.
A collection of hybrid stocks currently constitute
the bulk of the commercial production. The hybrids
under cultivation are female mouth-brooders and
believed to have originated from genetic crosses of
predominantly blue tilapia (0. aureus) and ancil-
lary 0. niloticus, 0. mossambicus, and 0. hornorum
species. Some evidence of genes from T. rendalli
and S. melanotheron are also apparent. Two popu-
lar hybrids are the Florida red, a species cross
between 0. aureus and 0. mossambicus, and the
hybrid between the 0. aureus and 0. niloticus
tilapias. The aurea strain is principally used be-
cause of its tolerance to cold water temperatures.

Life history characteristics
Tilapia are known for their ability to sexually
mature at a small size, around 8-10 cm (3-4 in.) in
body length, and a young age (sometimes when 2-3
months old). Adult fish are known to live six to
eight years, but some fish eleven to twelve years of
age have been reported. In temperate regions, the
spawning season of tilapia usually begins during
the spring months when water temperatures rise,
and spawning continues throughout the year as
long as water temperatures are above 22'C (72'F).

As mentioned above, tilapia have an elaborate
breeding behavior and are substrate nest builders.
In most cases, males establish and aggressively.
defend territories. Nests are built in the'form of
shallow pits in the pond bottom, and are used for
courting and spawning. After the female releases
her eggs and fertilization takes place, most parent
tilapia will pick up the eggs from the nest, incu-
bate, and protect their young in their mouths
(mouth brooders). A few species will leave the eggs
on the spawning substrate and incubate the
embryos by fanning water through them with their
fins.

Depending on age, body size, and mode of egg
incubation, female tilapia have a large variation in
the number of eggs they produced. Blue female
tilapia are reported to lay around 9-10 eggs per
gram of body weight (around 4,500 eggs/pound).
The eggs of hybrid tilapia are yellow-brown in color,
egg shaped, and will sink to the bottom when
spawned. The eggs vary in size from an average of
2 to 4 mm (0.08-0.16 in.) in diameter, depending on








Species account

Taxonomy and distribution
Tilapia is a generic term used to designate a
group of commercially important food fish belonging
to the family Cichlidae; the expression is
derived from the African native Bechuana word
"thlape", meaning fish. Cichlids are classified in
the large order Perciformes, and inhabit the fresh
and brackish waters of Africa, the Middle East,
coastal India, Central and South America. True
tilapias, however, are native only to Africa and the
Middle East. Although exotic to the United States,
populations of tilapia are now established in
Arizona, California, Hawaii, Florida, Nevada, North
Carolina, and Texas.

Cichlids are well known as colorful aquarium
fish, and for their ability to adapt to new environ-
ments. Cichlids also display highly organized breed-
ing activities. Because of their complex evolutionary
biology, cichlid classification and naming is one of
confusion and constant modification. Consequently,
the tilapias have recently been classified into three
genera. A distinguishing characteristic between the
genera is the type of care the parents provide to
their young. In the species of the genera
Sarotherodon and Oreochromis the parents will
incubate and protect the young in their mouths
(mouth brooding); in particular the Oreochromis
species are distinguished by maternal mouth-brood-
ing where parental care of the young is performed
primarily by the female. In contrast, incubation of
eggs in a lake or pond bottom built-in "nest" is
exhibited by those species belonging to the genus
Tilapia.

For simplicity purposes, all three genera and
hybrids in this text will be referred to as tilapia.
Important commercial species include: the
Mozambique or Java tilapia (Oreochromis
mossambicus, also known as Tilapia mossambica),
blue tilapia (0. aureus, a.k.a. Tilapia aurea), Nile
tilapia (0. niloticus, a.k.a.Tilapia nilotica), Zanzi-
bar or Wami tilapia (0. hornorum, a.k.a.Tilapia
urolepis), and the redbelly tilapia (O.zilli, a.k.a.
Tilapia zilli).

Culture

History
Tilapia have been raised as food for human con-
sumption for a long time; tilapia farming is believed
to have originated some 2,500 years ago.


Tilapia have also been transplanted to many
countries outside their native range and are now
farmed worldwide. In the United States, commer-
cial culture of tilapia is concentrated in Arizona,
California, and Florida. It is not clear, however,
what species of tilapia are under cultivation.
A collection of hybrid stocks currently constitute
the bulk of the commercial production. The hybrids
under cultivation are female mouth-brooders and
believed to have originated from genetic crosses of
predominantly blue tilapia (0. aureus) and ancil-
lary 0. niloticus, 0. mossambicus, and 0. hornorum
species. Some evidence of genes from T. rendalli
and S. melanotheron are also apparent. Two popu-
lar hybrids are the Florida red, a species cross
between 0. aureus and 0. mossambicus, and the
hybrid between the 0. aureus and 0. niloticus
tilapias. The aurea strain is principally used be-
cause of its tolerance to cold water temperatures.

Life history characteristics
Tilapia are known for their ability to sexually
mature at a small size, around 8-10 cm (3-4 in.) in
body length, and a young age (sometimes when 2-3
months old). Adult fish are known to live six to
eight years, but some fish eleven to twelve years of
age have been reported. In temperate regions, the
spawning season of tilapia usually begins during
the spring months when water temperatures rise,
and spawning continues throughout the year as
long as water temperatures are above 22'C (72'F).

As mentioned above, tilapia have an elaborate
breeding behavior and are substrate nest builders.
In most cases, males establish and aggressively.
defend territories. Nests are built in the'form of
shallow pits in the pond bottom, and are used for
courting and spawning. After the female releases
her eggs and fertilization takes place, most parent
tilapia will pick up the eggs from the nest, incu-
bate, and protect their young in their mouths
(mouth brooders). A few species will leave the eggs
on the spawning substrate and incubate the
embryos by fanning water through them with their
fins.

Depending on age, body size, and mode of egg
incubation, female tilapia have a large variation in
the number of eggs they produced. Blue female
tilapia are reported to lay around 9-10 eggs per
gram of body weight (around 4,500 eggs/pound).
The eggs of hybrid tilapia are yellow-brown in color,
egg shaped, and will sink to the bottom when
spawned. The eggs vary in size from an average of
2 to 4 mm (0.08-0.16 in.) in diameter, depending on








the species and number of spawns. After fertiliza-
tion, eggs hatch in 2 to 4 days, depending on water
temperature. Newly-hatched embryos absorb their
yolks in 3 to 4 days. The free-swimming young are
then protected by their parents for several days. In
mouth-brooding tilapias, incubation, hatching, and
care of the young may last a period of about three
weeks. After yolk absorption, young tilapias
actively feed on a varied diet, such as plankton and
detritus.

Production systems
In the United States, tilapia are considered
important for their food value. These fish have also
been popularized for their use in waste-water treat-
ment schemes and aquatic-weed control programs.

Because of the diversity of culture systems it is
impractical to describe all the different operations
used for raising tilapia commercially. Life stages
and culture technology for commercial production
of hybrid tilapia in the United States are described
in Figure 1. Domestic production of hybrid tilapia
consist mainly of all-male populations, and are
raised primarily as a high-quality fish for human
food. Culture is carried out in indoor tanks, water
recirculating systems, outdoor raceways, ponds,
and floating cages. In several states, primarily
Florida and California, tilapia are also fished
commercially. "Extensive" pond culture methods
for tilapia, traditional in many countries through-
out the world, are not commonly used in the United
States. For example, culture of tilapia in wastewa-
ter fed ponds, a viable and less expensive produc-
tion system, is not considered acceptable for
ecological or sanitary reasons.

Tilapia growth rates are influenced by a variety
of factors; water temperature, sex, supplemental
feeding, and stocking density noticeably affect their
growth rate. Tilapia are susceptible to cold water
temperatures, and will not over-winter in most
temperate climates. Most hybrid tilapia will stop
eating at water temperatures below 16C (61F),
and will begin to die at around 13"C (55'F). Water
temperatures between 25-32C (77-90'F) are
preferred for raising hybrid tilapia in intensive
culture.

In populations of tilapia, males grow faster and
more uniform in size than females. A predomi-
nantly male population also tends to reduce repro-
duction, overpopulation and stunting offish in pro-
duction ponds. For these reasons, a common cul-
ture practice is to raise an all-male population. A


monosex population can be achieved in several
ways. Customarily, fish are visually sexed at a
young age (20-30 g) and females discarded from the
grow-out system. Another common method for
obtaining an all-male population is achieving sex
reversal by oral administration of androgenic
hormones (e.g. a mixture of 60 mg of methyl testos-
terone per kilogram of food will treat approximately
5,000 newly hatched fry, fed 2-4 times per day for
3-4 weeks). Use of hormones in sex reversal offish
is currently under evaluation by the U.S. Food and
Drug Administration. Faster growth rates and
monosex populations are also obtained by crossing
different species. For example, crosses betweenO.
0. niloticus and 0. aureus produce a high percent-
age of males. A recently developed technique for
obtaining a monosex male population is by produc-
ing "supermales" (see Tave 1990). Supermales are
produced by hormonal sex reversal and artificial
chromosomal manipulations.

Little data are available on the efficiency of
hybrid tilapia to convert feed into meat. With the
use of high-quality formulated diets, the feed con-
version should range between 0.33 to 0.67 g offish
weight gain per gram of practical diet consumed
(e.g 1.5-3 pounds of feed/1 pound of fish). Young
hybrid tilapia are easily weaned and grow fast to
market size when fed formulated diets. Fast
growth rates are common when fish are fed food-
stuffs containing levels of 35-50% protein for fish <
1 g (0.04 oz); 30-40% for 1-5 g (0.04-0.18 oz) fish and
25-30% for 5-25 g (0.18-0.88 oz) animals. For larger
fish, recommended dietary levels vary from 25%
protein for fish raised in ponds, 28-32% when
reared in cages, to 35-40% when fish are grown in
tanks. Tilapia growth rates also increase with mul-
tiple daily feedings (3-8 times a day depending on
fish size). Feed allowance for young fish (< 25 g) is
usually 6-15% of their body weight per day, and
older fish (>25 g), 1-3% of their body weight.

Recommended stocking densities for table-size
tilapia production are extremely variable, and vary
according to fish size and system of production. In
fed and aerated production ponds, young (50 g)
hybrid tilapia are usually stocked at 9,500 to
19,500 fish per hectare (4,000 to 8,000 fish/acre).
In tanks or raceways, tilapia of 25-50 g (0.88-1.77
oz) in body size are stocked at densities between
140 and 248 fish/m3 (4-7 fish/ft3) of container space.
In final grow-out production cages, stocking densi-
ties for 60-100 g hybrid tilapia range from 250 to
400 fish per cubic meter (7-11 fish/ft3) of cage.
When cages are placed in ponds, the pond stocking








density cannot exceed those numbers (e.g. fish/acre)
which would be achieved by growing the fish free-
swimming in the pond.

The estimated time to raise hybrid tilapia from
egg to food-size fish is highly variable, but is usu-
ally in a range between 6 and 12 months. The time
required is primarily dependant on water tempera-
ture, fish density, and quality of diet.

Product forms
Hybrid tilapia are commonly sold as red or
golden tilapia. Live tilapia are marketed in the 450
to 680 grams (1-1.5 pound) range, and yield be-
tween 30 to 39 percent whole fish to boneless fillets.
Fish are most often traded as whole (dressed and
undressed), fresh and frozen. Nutritive value of hy-
brid tilapia is considered around: 96 kcal/100 grams
of raw meat, 19.2% protein and 2.3% fat by weight.

A serious problem when marketing tilapia is "off-
flavor"; the flesh offish having a musty/muddy odor
and flavor. Holding the fish in clean and continuous
flowing water for 7 to 10 days will usually reduce
the problem.

Future outlook
In the United States, production and sale of
tilapia have severe legal restrictions and are pro-
hibited in many states. Those persons interested in
raising or selling tilapias should contact the appro-
priate agency in their state.

To the author's knowledge, only a handful of
tilapia operations in the United States have been
considered successful aquaculture business ven-
tures. High costs of production, environmental
constraints (e.g. low water temperatures), lack of
consumer product demand, and competition from
high quality, low cost imported fish are major con-
straints for development of the tilapia aquaculture
industry.

Promising species for commercial grow-out
include the 0. niloticus and 0. aureus species, and
their corresponding hybrids. Cage culture in large,
man-made bodies of water or heated effluents, and
harvesting from established exotic populations ap-
pear as promising and immediate competitive alter-
natives for economic solvency of tilapia enterprises.


Sources of information and
selected references
A wealth of information has accumulated on the
biology and culture of tilapia. Most of the informa-
tion that exists in the literature, however, empha-
sizes husbandry methods in extensive pond culture
conditions. In the United States, little has been
published on commercially raising hybrid tilapia to
market size. Listed below are some essential
sources for information and general references on
culturing tilapia. Numerous leaflets, pamphlets,
and guides for raising tilapia have also been pro-
duced by cooperative extension offices across the
country.
A special permit is required for the possession of
tilapia in the state of Florida. Please contact the
Florida Game and Fresh Water Fish Commission
and your county extension agent if you are inter-
ested in farming tilapias.

Aquaculture Magazine, P.O. Box 2329,
Asheville, North Carolina 28802.

Balarin, J.D. and R.D. Haller. 1982. The intensive
culture of tilapia in tanks, raceways and cages.
In: Muir, J.F. & R.J. Roberts (eds.). Recent
Advances in Aquaculture. Croom Helm Ltd:
London, England.

Fishelson, L. and Z. Yaron (compilers). 1983.
International symposium on tilapia in aquacul-
ture. Tel Aviv University: Tel Aviv, Israel.

Fisheries and Aquatic Sciences Department.
University of Florida, 7922 NW 71"t St.,
Gainesville, Florida 32606. Telephone:
(904) 392-9617.

Florida Game and Fresh Water Fish Commission.
Aquaculture Project, 3900 Drane Field Rd.,
Lakeland, Florida 33803. Telephone:
(813) 644-9269 or (800) 282-8002.

Hepher, B. & Y. Pruginin. 1981. Commercial fish
farming: with special reference to fish culture in
Israel. John Wiley & Sons: New York,
New York.

National Aquaculture Information Center.
National Agricultural Library, Room 304, 10301
Baltimore Blvd., Beltsville, Maryland 20705.
Telephone: (301) 344-3704.








Popma, T.J. and B.W. Green. 1990. Sex reversal of
tilapia in earthen ponds. International Center
for Aquaculture: Auburn University, Alabama.

Pullin, R.S.V. 1988. The second international sym-
posium on tilapia in aquaculture. International
Center for Living Aquatic Resources Manage-
ment (ICLARM): Manila, Philippines.

Pullin, R.S.V. and R.H. Lowe-McConnell (eds.).
1982. The biology and culture of tilapias. Inter-
national Center for Living Aquatic Resources
Management (ICLARM): Manila, Philippines.

Seafood Business Magazine. Journal Pub., P.O.
Box 908, Rockland, Maryland 04841.

Seafood Leader Magazine. Waterfront Press Co.,
1115 NW 46t St., Seattle, Washington 98107.

Tave, D. 1990. Supermale tilapia. Aquaculture
Magazine 16(2): 69-72.

Trewavas, E. 1983. Tilapiine fishes of the genera
Sarotherodon, Oreochromis, and Danakilia.
Cornell University Press: Ithaca, New York.

Torrans, L. 1988. Blue tilapia culture in Arkansas.
University of Arkansas Cooperative Extension
Program, EC560: Pine Bluff, Arkansas.


Useful unit conversions
Temperature relations: 'F = ('C x 1.8) + 32
"C = ('F- 32)/ 1.8


You Have
meter (m)
centimeter (cm
millimeter (mr
hectare (ha)
liter (1)
cubic meter (m
gram (g)
gram (g)
kilogram (kg)
liters per minu
(/min)


Multiply By
39.37
i) 0.394
n) 0.039
2.471
0.264
3) 35.31
0.0022
0.0353
2.205
te
0.264


grams per liter (g/1) 1.0


To Get


Divide By


To Get
inches (in.)
inches (in.)
inches (in.)
acres (A)
gallons (gal)
cubic feet (ft3)
pounds (Ib)
ounces (oz)
pounds (Ib)

gallons per
minute (gpm)
parts per
thousand (ppt)


You Have









Production considerations


Tilapia are well known for their broad tolerance to environmental conditions. However, little information
is available on the culture of hybrid tilapia for commercial purposes in the United States. For these reasons,
biological and environmental optimum parameters for production of hybrid tilapia are difficult to ascertain.
The values presented below indicate expected life cycle attributes and water quality averages or ranges for
maximum survival, growth, and reproduction of hybrid tilapias under culture conditions. Figures are to be
used only as guidelines and based on personal experience of the author, as well as scattered information in
the aquaculture literature.


Life history characteristics
" Age at sexual maturity (months): 5-6
" Size at sexual maturity (grams): 28-350
" Stocking ratio for spawning: 2-5 females to 1 male
" Annual spawns: 7-10 broods
" Spawning success e.g. spawns/week: 20-30%
" Eggs/gram offish: 1-4
" Survival of egg to fry (< 5 g): 70-90%
* Survival of fry to
fingerling (5 to 30 grams): 60-90%
* Survival of fingerling to
market (30 to 680 grams): 70-98%


Environmental requirements


* Water Temperatures for
Optimum growth:
Optimum spawning and
embryo development:
" Dissolved Oxygen (DO):
" Carbon Dioxide:
" Salinity:
" Turbidity:
" pH:
a Alkalinity:
" Total Ammonia Nitrogen (TAN):


28-320C

25-300C
above 3.0 mg/1
below 15 mg/1
0-28 ppt
25-100 mg/1
6.0-8.5
50-700 mg/1
0.5-1 mg/1


Figure 1. Life stages and primary culture technology for hybrid tilapla.


EX RE VERSA L

TRO/GhlS














































































COOPERATIVE EXTENSION SERVICE,UNIVERSITY OF FLORIDA, INSTITUTE OF FOODAND AGRICULTURAL SCIENCES,JohnT. Woeste,
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 institutions that
function without regard to race, color, sex, age, handicap or national origin. Single copies of extension publications (excluding 4-H and youth
publications) 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, Florida32611. Before publicizing
this publication, editors should contact this address to determine availability.




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