1. TILAPIA CULTURE by Leonard Lovshin
Department of Fisheries and Allied Aquacultures
Auburn University, AL U.S.A.
Tilapia Culture by Leonard Lovshin, Department of Fisheries and Allied Aquacultures, Auburn University, Alabama.

2. Tilapia are native to Africa, Israel and Jordan
Water Temperatures
for:
Best growth- above 770F
Spawning - above 680F
Tilapia are native to the lakes and rivers of Africa, Israel and Jordan and have been present on African dinner plates for thousands of years. Over 80 tilapia species have been identified in Africa. Tilapia have been introduced to most tropical and temperate climate countries in the world. Tilapia need water temperatures above 770F to grow well, 680F to reproduce and will die in water below 50 to 540F. Tilapia must be placed in warm water sources or in greenhouses to survive winter water temperatures in temperate climates.
Death- 50 to 540F

3. Popular Cultured Tilapias
Nile Tilapia
Mozambique Tilapia
Blue Tilapia
Red Tilapia
Only 3 or 4 tilapia species are farmed widely. Presently, Nile tilapia is the most popular tilapia for culture because of its fast growth. The red tilapia variety is popular because consumers are attracted to its pleasing color and some red tilapia strains can be cultured in full strength sea water. The red coloration is a genetic mutation found in Nile, Mozambique and Blue tilapia. The blue tilapia is native to Israel and is more tolerant to cold water temperatures than most tilapia. The Nile tilapia has a banded caudal fin which distinguishes it from the blue tilapia. Mozambique tilapia was the first and most widely distributed tilapia species outside of Africa and is present in most Asian countries. However, its slow growth and dark color have reduced its importance as a culture fish.

4. Food Habits Tilapia feed low on the food chain phytoplankton
Tilapia feed low on the food chain. The tilapia intestine is over 3 times the body length, indicating that tilapia are primarily herbivorous.Tilapia feed on zooplankton when they are small but feed almost exclusively on phytoplankton and other forms of algae as juveniles and adults.
zooplankton

5. 1. All tilapia can be 2. Mozambique tilapia
Tilapia can be cultured in fresh and salt water.
1. All tilapia can be
grown in fresh water.
2. Mozambique tilapia
and red tilapia with
Mozambique tilapia
genes can be grown
in salt water.
Most tilapia are cultured in fresh water. However, as land with access to fresh water becomes limiting, more farmers are trying to culture tilapia in brackish and sea water. The Mozambique tilapia and red tilapia with Mozambique ancestors can be grown in full strength sea water. Nile tilapia and Blue tilapia will grow well in water up to 15 ppt saltwater. All species of tilapia reproduce best in fresh water or salt water with salinities lower than 10 ppt.

6. Reproduction Males dig and defend a nest Females incubate eggs
and defend the fry
Males dig a bowl shaped nested in soft bottom substrates. Nests are located in shallow water. The male defends his nest territory from invasion by other males. Males and females reach sexual maturity when they are 3 to 5 months of age. Females ready to spawn enter a nest and after a short courtship, lay their eggs on the nest bottom. The male quickly fertilizes the eggs. The female picks up the fertilized eggs in her mouth for incubation. The female leaves the nest area to care for her eggs. The male is ready to spawn with another female. The female will incubate the eggs in her mouth for 5 to 6 days before they hatch. The female will continue to care for the yolk-sac fry in her mouth. Fry that are free-swimming and leave the females mouth to feed are still cared for by the female. At any sign of danger, the female signals the fry and they swim back into her mouth for protection. The female cares for the eggs and fry for 2 to 3 weeks. During this time, she does not eat. Females can spawn 4 to 6 times a year where water temperature permit. Females spawn about 1 to 2 eggs per gram body weight. A 400 g female can spawn between 400 to 800 eggs. Tilapia egg fecundity per spawn is low but egg and fry survival are high because of female care. Fry are 8 to 10 mm long at hatch.

7. Tilapia can be spawned in:
1. ponds
2. cages
Tilapia spawn naturally in a variety of containers. Most cultured tilapia are spawned in small earthen ponds. Fry and small fingerlings are periodically harvested from the ponds with a seine net. Normal stocking density in earthen ponds is 1 brooder per m2 and a ratio of 1 male for every 2 to 3 females. Tilapia can also be spawned in small mesh cages ( hapas ) or in concrete or fiberglass tanks. Tilapia do not need a soft substrate to spawn. Males, though unable to dig a nest, still defend a territory and females lay their eggs on the hard bottom. Stocking density in cages or tanks is 3 to 5 brooders per m2 and a ratio of 1 male to 1 female.
3. tanks

8. Fry can be harvested: 1. 18 days after hatch 2. 40 days after hatch
Removing fry from spawning ponds 18 days after stocking brood fish results in higher numbers of fry per female but survival of fragile fry is reduced due to handling stress. Larger fry ( 1 g ) can be captured 40 days after stocking brood fish to increase survival. However, cannibalism of large fry on small fry lowers the number of fry harvested per female. Most tilapia farmers prefer to harvest fry 18 days after stocking brood fish because the number of offspring per female available for stocking nursery ponds is higher than waiting 40 days after stocking brood fish to harvest fry.

9. Fry can be: 1. Partial harvested 2. Completely harvested Fry removal
Small fry ( 0.05 g ) can be harvested 18 days after stocking brood fish by partial seine harvest of full ponds or by pond draining to remove all fry. Pond margins are seined with a 1.6-mm mesh net daily to remove fry. Daily seining is continued for 1 month after which the pond is drained and a new spawning cycle started. Complete fry harvest is accomplished by draining the pond water to a sump or catch basin. Brood fish are removed from the catch basin before fry removal. Brood fish are lifted from the catch basin with a large mesh net that was placed in the catch basin before the pond was filled with water and the spawning cycle started. After brood fish are removed, fry are captured with 1.6-mm mesh nets or dip-nets. Spawning ponds must be poisoned or completely dried to eliminate any fry that remain in the pond after harvest before the next spawning cycle is started. Often, male and female brooders are held separately for a 7 to 10 day rest period before restocking in the spawning pond.
Brooder removal
Fry removal

10. Eggs can be removed from females:
Incubating tilapia eggs
Some farmers prefer to remove the eggs from the mouths of females and incubate the eggs artificially. Farmers collecting eggs must be able to easily collect the females. Brood fish are stocked into hapas to facilitate female collection. Females are collected 5 days after placing them with the males to assure that eggs and not fry are collected. The eggs are transferred to a hatchery and placed in incubators with clean flowing water. The recently hatched yolk-sac fry are removed from the incubators and place in containers with clean flowing water to allow them to absorb their yolk sacs and become stronger. When the fry are free swimming and looking for food, they can be transferred to ponds with zooplankton or placed in larger containers where they are fed a nutritious powdered feed.
Yolk-sac tilapia fry

11. Tilapia can be cultured as:
1. Mixed sexes - males and females together
2. Mono-sex - only males
Tilapia reach sexual maturity at 3 to 5 months of age and will reproduce in grow-out ponds. To reduce the possibility of unwanted reproduction and stunting in grow-out ponds, male tilapia are cultured alone. Male tilapia are preferred because they grow faster than the females.

12. Grow-out: Mixed-sex Culture Advantages: 1. Technically easy
Disadvantages:
1. Small harvest weight
2. Mixed sizes at harvest
Mixed-sex tilapia are easy to raise and permit low income, inexperienced farmers an opportunity to farm fish. Mixed-sex tilapia fingerlings can be grown to 100 to 150 g in 4 to 6 months before offspring from unwanted reproduction becomes a problem. Ponds that are not harvested in 4 to 6 months quickly fill with offspring that compete for food with the stocked tilapia. Tilapia growth slows and many small tilapia are harvested. However, mixed-sex tilapia yields per pond area can be very high and is a good method to culture tilapia if a small fish is acceptable by consumers.

13. 2. Uniform size at harvest Disadvantages: 1. Technically difficult
Mono-sex culture
Advantages:
1. Large harvest weight
2. Uniform size at harvest
Disadvantages:
1. Technically difficult
Often, a small tilapia is unacceptable to consumers and a larger fish is required. Stocking mostly male fish will result in a larger weight and more uniform size at harvest because few tilapia offspring are present in the grow-out pond. However, producing mostly male tilapia fingerlings and growing them to harvest requires understanding monosex tilapia culture techniques. Inexperienced tilapia farmers often have problems producing male tilapia fingerlings for stocking into their culture ponds.

14. increase final harvest weight.
Stocking a predacious fish with mixed-sex tilapia will control tilapia density and
increase final harvest weight.
Largemouth bass in the U. S. A.
Stocking a predacious fish together with the mixed-sex tilapia will reduce or eliminate tilapia offspring from grow-out ponds. Eliminating small tilapia will result in the stocked tilapia reaching a larger harvest weight than in ponds where offspring are not controlled. Examples of predacious fishes are the largemouth bass found in North America and the peacock bass native to South America. Predacious fishes must be stocked at a small size so that they are unable to eat the stocked tilapia.
Peacock bass in
South America

15. Mono-sex male tilapia populations can be produced by:
1. Visual selection
2. Hybridization
3. Sex-reversal
4. Genetic manipulation
Male Populations
Male tilapia populations can be produced by visual selection, hybridization, sex-reversal and genetic manipulation.

16. Visual Selection of the Genital Papilla
Female papilla with
oviduct
anus
Male papilla
Tilapia with a minimum weight of 25 to 30 g can be separated by visual inspection of the genital papilla. The male genital papilla is pointed and contains only the small urogenital pore which is difficult to observe. The female papilla is rounded and contains a small opening to the urinary duct and a larger oviduct. Selection is usually based on the presence or absence of the oviduct. Males are stocked for further growth while females can be used as brood stock or discarded. Visual selection of male tilapia is costly because of the extra labor needed to separate males from females.
anus

17. Hybridization Male Hornorum tilapia All-male hybrid tilapia
Two species of tilapia can be crossed to yield all-male offspring. The male Hornorum tilapia can be hybridized with the female Nile tilapia and offspring are all-male. However, the hybrid is fertile and can backcross with female Nile and Hornorum tilapia. Only genetically pure Hornorum and Nile tilapia will result in 100% male offspring. Maintaining pure lines of Nile and Hornorum tilapia over a long period of time is difficult. Additionally, hybrid fry yield per female is low compared with fry yield per female from pure species spawns.
Female Nile tilapia

18. Sex Reversal of Tilapia Fry
During the last 10 to 15 years, the most popular way to produce all-male populations is with hormone sex reversal of tilapia fry. Recently hatched tilapia fry obtained by harvest from spawning containers 18 days after brood fish are stocked or hatched from eggs taken from females are fed a powdered diet containing a male steroid for 20 to 28 days. Fry that would have been females if fed a steroid-free diet, will be functional males at the end of the hormone treatment. While all-male populations are hard to produce with sex reversal treatment, 95 to 98 % males are commonly produced.

19. Genetic Manipulation 1) XXF + XYM 2) XY”F” x XYM 3) XXF x YYM estrogen
XXF XY”F”
2) XY”F” x XYM
XXF + 2 XYM + YYM
3) XXF x YYM
100% XYM
Female Nile tilapia are homozygous ( XX ) and male Nile tilapia are heterozygous ( XY ) for sex. A pairing of genetically normal male and female Nile tilapia will result in 50 % male and 50% female offspring. Normal fry that are fed estrogen for 28 days will result in phenotypic all-female fry. However, 50% of these feminized fry are genetic females ( XX ) and 50% are genetic males ( XY ). These females are individually paired with normal males. A genetic female ( XX ) paired with a genetic male ( XY ) will have offspring that are 50% male and 50% female. Females from this crossing are discarded. When a genetically male female ( XY ) is crossed with a genetic male ( XY ) the offspring will be 25% female ( XX ) and 75% males ( 50% XY and 25 % YY ). Again, individual pairings with a genetic female ( XX ) are required to determine which male is YY. The YY males or “ supermales “ will sire 100% male offspring ( XY ) when paired with genetic ( XX ) females.

20. Tilapia are raised in: Small earthen ponds
Tilapia have been raised in small hand dug, family ponds for years. Commonly, mixed-sex tilapia fingerlings are stocked and fed with household food scraps and on-farm by-products. Pond waters can be fertilized with animal manures. The Guatemalan farmer in this photo uses the manure from the chickens placed in the enclosure over his pond to fertilize the pond water. The fish harvest is consumed by his family or sold to neighbors.

21. Tilapia are raised in: Large Earthen Ponds
Farmers that produce tilapia to sell in local or distant markets often stock large earthen ponds with male tilapia. Tilapia are stocked at 1 to 3/m3 in earthen ponds. When the tilapia reach a large size and are ready for harvest, they are removed from the pond with a seine net. Harvesting tilapia with a seine from a large pond is difficult work as the fish is adapt at jumping over or swimming under the seine.

22. Tilapia Raised In Floating Cages
Tilapia can be grown at 100 to 300/m3 in floating cages located on lakes and reservoirs. Water is freely exchanged between the cage and the water body holding the cage to remove fish wastes from the cage. Tilapia are easily cared for and harvested from a cage but must be protected against theft. Mixed-sex tilapia can be grown in cages enclosed with large-mesh net material because females are unable to reproduce and the cage does not fill up with offspring. Eggs drop through the cage mesh before the males can fertilize the eggs and females can collect them in their mouths. Most farmers growing tilapia in cages prefer to stock male tilapia.

23. Tilapia are raised in:
Circular tanks with partial water exchange and mechanical aeration
Tilapia can be cultured at 50 to 100/m3 in small, circular tanks with partial water exchange and mechanical aeration. One tank volume or less may be exchanged per day. Tanks are constructed with a drain located in the center of the tank. A circular water current generated by mechanical aerators carries feces and other settleable wastes to the drain for easy removal from the tank. Tilapia are easily harvested from small tanks and high yields are possible with small amounts of water exchange.

24. Raceways with constant water exchange
Tilapia are raised in:
Raceways with constant water exchange
Raceways have a constant water exchange which allows the highest tilapia stocking rates and yields per area of culture unit. Tilapia can be stocked 300 to 500/m3. Raceways can be circular or rectangular in shape. Water volume may be exchanged 1 to 5 times per hour. The flowing water sweeps fish feces from the culture unit. Notice that the water falls from one culture unit to the next by gravity. As the water passes from the higher culture unit to a lower one, the water is reoxygenated and can be reused 2 or 3 times without reduction in fish yield. However, a large quantity of water is required and supply by gravity is more economical than pumping.

25. Tilapia are raised in:
Indoors with water reuse, mechanical aeration and oxygen injection
Tilapia are commonly raised in culture units located indoors in regions with temperate climates to permit year round growth. Little freshwater is added to the culture unit to conserve water temperature. Suspended and dissolved fish wastes are removed from the water with mechanical and biological filtration to allow reuse of the water. Oxygen concentrations are maintained with mechanical aeration and often, injection of pure oxygen. Tanks are stocked with 10 to 50 tilapia/m3. Most tilapia produced in the United States are cultured in enclosed, water reuse systems because of the temperate climate.

26. Tilapia ponds can be fertilized with organic and inorganic fertilizers to increase yield
Fertilizing pond waters with organic and inorganic fertilizers increases tilapia yields by promoting the growth of phytoplankton and zooplankton consumed by the tilapia. Tilapia ponds are commonly located next to livestock enclosures so that manures are easily washed into the ponds during cleaning. Associating tilapia with ducks is a common practice in Asia.

27. Tilapia can be fed to increase yield
Most commercial tilapia farmers feed their tilapia to increase growth and yields. Tilapia have small stomachs and should be fed 2 to 3 times per day.

28. Tilapia can be fed Pelleted diets Agricultural by-products sinking
wheat bran
cottonseed meal
Tilapia can be fed agricultural by-products or pelleted diets that sink to the pond bottom or float on the water surface. Most commercial tilapia farmers use pelleted diets and prefer floating feeds if they are available. Tilapia raised in cages, tanks with partial water exchange and raceways must be fed nutritionally complete pelleted diets. Tilapia raised in large or small earthen ponds with no water exchange can be fed agricultural by-products or pelleted diets.
floating
rice bran

29. Tilapia can be sold to Neighbors and Friends
These young boys in Northeast Brazil are selling fresh tilapia door to door.

30. Tilapia can be purchased
At supermarkets and fish shops
fresh and frozen fillets
whole on ice
Tilapia are a popular food fish in the United States and are sold in supermarkets live, gutted and scaled with the head on, and as boneless fillets. About 89,220 tons of whole and filleted tilapia were import into the U. S. in 2000.

31. Tilapia farming in the U. S.
Most production is from enclosed, water reuse system
because of cold winter water temperatures.
Production costs are high.
Most tilapia are sold live or whole iced.
Presently, U. S. producers can’t compete with producers
in tropical climates for processed tilapia.
Fresh fillets are imported from Central and South America.
6. Frozen fillets are imported from Asia.
Most tilapia farmed in the U. S. are grown in enclosed, water reuse systems to prolong the growing season through the winter. The cost of growing tilapia in enclosed systems is higher than the cost of growing tilapia in earthen ponds and cages because of the high cost of heating and pumping water. Tilapia farmed in tropical climates cost less to raise than tilapia farmed in temperate climates. Thus, U. S. tilapia farmers have a difficult time competing economically with tilapia raised outside the U. S. in countries with tropical climates and imported to the U. S. by plane and ship. Over 80% of tilapia farmed in the U. S. are sold live because foreign tilapia growers can not compete for the live tilapia market. However, over 90% of the whole frozen and fresh and frozen processed tilapia sold in the U. S. is imported from Asia and Central and South America.

32. Advantages of Farming Tilapia
Feeds low on the food chain
Accepts wide range of feeds
Resistant to poor water quality, disease and handling
Good flesh quality
5. Fingerlings easy to produce year round
Tilapia have numerous qualities that favor it for farming. Tilapia feed low on the food chain, lowering the cost of growing tilapia in systems with abundant natural foods. Tilapia will accept a wide variety of agricultural by-products and pelleted feeds and they are resistant to poor water quality,disease and handling. Fingerlings can be produced year round where water temperatures permit. Tilapia have a firm, mild tasting, white flesh attractive to consumers.

33. Disadvantages of raising tilapia
Reach sexual maturity at a young age
Males grow faster than females
Difficult to harvest from earthen ponds with a seine
4. Low percentage of fillet removed from body
Tilapia have disadvantages as a culture fish. They are sensitive to low water temperatures and are best cultured in regions with a tropical climate. Tilapia reach sexual maturity at a young age and will spawn during growout to large market sizes. Male tilapia are favored for culture because reproduction during growout is reduced and males grow faster than the females. Tilapia are hard to capture from earthen ponds with a seine net because they will jump over and swim under a seine. The percentage of flesh by weight removed from the whole fish as a boneless fillet is about 33 %, low when compared with most farmed fish.

34. U. S. tilapia Production in 2000:
Over 3.1 billion pounds of farmed tilapia are harvest world-wide yearly.
Major producers are:
China > Philippines > Thailand
U. S. tilapia Production in 2000:
18,191,000 lbs
Tilapia are farmed in many countries. China, including Tiawan, is the world leader of farmed tilapia harvesting over 1,540,000 tons in The Philippines and Thailand are also major producers of tilapia in Asia. Brazil, Colombia, Ecuador and Costa Rica harvest most of the tilapia farmed in the Americas. U. S. tilapia farmers harvested 18.2 million pounds in 2000.

35. EAT MORE TILAPIA
Harvest of farmed tilapia will continue to grow as consumers become more familiar with the tasty, firm white flesh of this fish. Look for tilapia in the seafood section of your local supermarkets.

36. The
End