Aquaculture is the farming of aquatic organisms, includingfish, molluscs, crustaceans and aquatic plants, in water . Tilapiaare currently known as ‘aquatic chicken’ due to their highgrowth rates, adaptability to a wide range of environmentalconditions and ability to grow and reproduce in captivity.Tilapia is freshwater fish. They are native to Africa, but wereintroduced into many tropical, subtropical and temperateregions of the world. In 2011 tilapia interred Iraq by Euphratesriver coming from Syria farms & distribute to many cites in Iraqincluding Baghdad, Basrah, Al-Nassiriya & Al-Qadissiyacausing problems with the original fishes because thecompetition & changing the food chain in aquatic bodes of Iraq.(INRHC, 2012). Tilapia used as biological control because thisfish feed on mosquito female (Malaria host) which transportingMalaria disease. (INRHC, 2012)Introduction:2
Figure (1): Main producer countries of Oreochromis niloticus. 3Source: El-Sayed, (2006).
The name ‘tilapia’ was derived from the AfricanBushman word meaning ‘fish’ (Trewavas, 1982).Tilapias represent a large number of freshwaterfish species within the family Cichlidae. Accordingto (Kaufman and Liem, 1982).Kingdom: AnimaliaPhylum: ChordataClass: ActinopterygiiOrder: PerciformesFamily: CichidaeGenus: TilapiaClassification:4
Nile Tilapia Mozambique TilapiaBlue Tilapia Red TilapiaPopular Cultured Tilapias:5
Major cultured species:Figure (2): Aquaculture production of tilapia by species in million tonesas reported by the FAO. 6Source: Mark et al.,(2004).
Environmental Requirements:Parameter Range Optimumfor growthReferenceSalinity (ppt) Up to36Up to 19 El-Sayed (2006).D.O.(Mg/L)Downto 0.1> 3 Magid and Babiker(1975); Ross (2000).Temperature(Cᵒ)8 - 42 22 - 29 Sarig (1969); Morgan(1972); Mires (1995).PH 3.7 - 11 7 - 9 Ross (2000).Ammonia(Mg/L)Up to7.1< 0.05 El-Shafey (1998); Rednerand Stickney (1979).Table 1: Limits and optima of water quality parameters for tilapia.7
Tilapias are very good aquaculture speciespartially because they are omnivorous meaningthat they feed on a low trophic level. They areable to produce high quality protein from lessrefined protein sources thus making themeecologically attractive as sources of animalprotein for humans (Jauncey, 1998). The bestgrowth performance of tilapia is exhibited whenthey are fed a balanced diet that provides aproper balance of protein, carbohydrates, lipids,vitamins, minerals.Nutritional Requirements of Tilapia:8
Nutritional requirements of fish differ fordifferent species and more importantly varywith life stage. According to Fitzsimmons,(1997) fry and fingerlings require diets withhigher protein, lipids, vitamins and mineralsand lower carbohydrates as they are developingmuscle, internal organs and bones with rapidgrowth. From various studies the proteinrequirements of juvenile tilapia have beenreported to range between 30-56% (Jauncey,1998; Suresh, 2003).9
(Allowance) in practical feeding of fish involvestwo options. One is to feed the fish to satiation and theother is to feed a restricted ration (Suresh, 2003). Bestgrowth is normally achieved by feeding to satiation.But satiation levels are not necessarily the mosteconomic feeding levels, because food conversion atsatiation levels is often poor. Also, it is difficult todetermine satiation levels in fish because foodconsumption occurs in the water medium. This maylead to overfeeding, which is wasteful and deleteriousto water quality. As a result, restricted rations arerecommended for feeding fish (Suresh, 2003).Feeding rate:11
Table 3:Feeding rates and frequencies for various sizes ofTilapias at 28 co, (Juancey and Roos 1982).Size Daily feeding (% of fish weight) Times fed daily2 day old to 1g 30 – 10 81 – 5 g 10 – 6 65 – 20 g 6 – 4 420 – 100 g 4 – 3 3 – 4> 100 g 3 312Source: Fish Base, (2006).
Reproduction and Seed Production:Tilapia can reach sexual maturity between 50 and100 gm. If placed in ponds, tilapia will readilyspawn, and, within a short time period, a pond canbecome overloaded with fingerlings.Tilapia are mouth brooders. The male establishesa territory and builds a round nest in the pondbottom. The nest’s diameter correlates to the male’ssize. The female enters the nest and lays her eggs.13
The eggs are then fertilized by the male. Thefemale then collects and incubates the eggs,which are yellow-colored, in her mouth. Tilapiaeggs hatch in about four to eight days. Afterhatching, the fry remain in the female’s mouthfor another three to five days. Fry begin to swimfreely in schools, but may return to the mouth ofthe female when threatened. Females may spawnevery four to six weeks but may spawn sooner ifeggs or fry are removed during mouth brooding.14
Sex Distinguishing:Male papilla for urine & fertilizationFemale papilla with oviduct onlyAnus (feces &urine excrete)Figure (3): Distinguishing between Tilapia sexes.Anus (feces excretion only)Source: Fish Base, (2006).
16And defend the fryFemales incubate eggsReproduction:Eggs of Tilapia
17Video (1): Parental care in TilapiaSource: Fish Base, (2006).
The introduction of tilapia into those areas was for:1. Farming as food fish.2. Recreational fishing.3. Aquatic weed control.4. Research purposes.Conclusion:18Tilapia is still a source of high-quality proteinsuitable for human consumption, at a relativelylow cost. Developing countries in Asia are theleaders of world aquaculture production .
Tilapia have many attributes that make them anideal candidate for aquaculture. These include:1. Fast growth.2. Tolerance to a wide range of environmentalconditions.3. Resistance to stress and disease.4. Ability to reproduce in captivity and shortgeneration time.5. Feeding on low trophic levels and acceptance ofartificial feeds immediately after yolk-sacabsorption.19
References:El-Sayed, A.M. (2006). Tilapia culture in salt water: Environmental requirements,nutritional implications and economic potentials. Eighth Symposium onAdvances in Nutritional Aquaculture. November 15–17, Nuevo Leon, Mexico.Fish Base. (2006). Species Summaries for Tilapia. www.fishbase.org. Last accessed:15 May 2006.Fitzsimmons, K. (1997). Introduction to tilapia nutrition. In: Proceedings of theFourth International Symposium on Tilapia in Aquaculture, pp. 9-12. Ithaca, N.Y.: Northeast Regional Agricultural Engineering Service Publication, No. NRAES– 106.INHRC (Iraq Natural History Research Center & Museum).(2012). Tilapia fish andits danger for Iraqi Environment. Baghdad University.http://www.nhm.uobaghdad.edu.iq/ArticleShow.aspx?ID=24 .ISSG (Invasive Species Specialist Group).(2006). Ecology of Oreochromis spp.Global Invasive Species Database. 12 January 2006.Jauncey, K. (1998). Tilapia Feeds and Feeding. Pisces Press, Stirling, Scotland, 241pp.Jauncey, K. and Ross, B. (1982). A Guide to Tilapia Feeds and Feeding. University ofStirling, Stirling, Scotland, 111 pp.20
Kaufman, L. and Liem, K.F. (1982). Fishes of the suborder Labroidei (Pisces:Perciformes): phylogeny,ecology and evolutionary significance. Breviora 472, 1–19.Magid, A., and M. M. Babiker.(1975). Oxygen consumption and respiratory behaviourof three Nile fishes. Hydrobiologia 46: 359–367.MARK S. PETERSON, WILLIAM T. SLACK, NANCY J. BROWN-PETERSON, AND JENNIFERL. MCDONALD.(2004). Reproduction in Nonnative Environments: Establishment ofNile. Tilapia, Oreochromis niloticus, in Coastal Mississippi Watersheds.Copeia,2004(4), pp. 842–849Pillay, T.V.R. (1990). Aquaculture Principles and Practices. Fishing News Books,Blackwell Science,Oxford, UK, 575 pp.Redner, B. D., and R. R. Stickney. (1979). Acclimation to ammonia by Tilapia aurea.Trans. Am. Fish. Soc. 108:383–388.Suresh, V. (2003). Tilapias. In: Lucas, J.S. and Southgate, P.C., (Eds.) Aquaculture:Farming of Aquatic Animals and Plants, pp. 321-345. Oxford, UK: BlackwellPublishing.Trewavas, E. (1982). Tilapias: taxonomy and speciation. In: Pullin, R.V.S. and Lowe-McConnell,R.H. (eds) The Biology and Culture of Tilapias. ICLARM ConferenceProceedings No. 7, ICLARM, Manila, Philippines, pp. 3–13.21References: