For aquaculture, note that there are five subspecies with different characteristics: Sarotherodon m. melanotheron Rüppell, 1852; Sarotherodon m. heudelotii (Duméril, 1861); Sarotherodon m. leonensis (Thys van den Audenaerde, 1971); Sarotherodon m. paludinosus Trewavas, 1983 and Sarotherodon m. nigripinnis (Guichenot 1861); full descriptions and a synonymy are in Trewavas (1983).

Common names: English - black-chinned tilapia (somewhat confusing as melanic patterns on the head and body are variable among and within subspecies); French - carpe (also confusing; used only in Côte d’Ivoire).

History of use: Used for centuries as a food fish; found in West African brackish waters and adjacent freshwaters (mainly lagoons, estuaries, the lower reaches of rivers and neighboring lakes and reservoirs) from Senegal to the former Zaïre; a popular aquarium fish, first imported to Europe in 1907; its potential for aquaculture was ignored until recent attempts were made to adapt for extensive aquaculture the highly productive traditional brushpark fisheries or ‘acadjas’ (brushwood bundles in shallow lagoons, that attract fish and provide shelter and abundant food, especially periphyton) from which large quantities of this species are harvested (7-20 t ? ha-1 ? year-1 of fish from 20 to 560 g) (Hem and Avit 1996); other pond, cage and enclosure trials had proven unsuccessful, except for producing small fish around 50 g (indicative growth data for manured and supplementary-fed ponds, 0.5- 0.7 g ? day-1 up to 25-35 g with stunting thereafter, net annual production, 1.9-3.5 t/ha; cages, 0.5 to 0.7 g?day-1 up to 50-60 g and 0.1-0.2 g?day-1 thereafter); such trials, in Benin, Côte d’Ivoire and Nigeria used Sarotherodon m. melanotheron; very recent work in Côte d’Ivoire (Agnèse 1996; Gilles et al. 1998) has shown much faster growth (more than 2 g?day-1) in fish that originated near Dakar, Senegal, presumably Sarotherodon m. heudelotii, or Sarotherodon m. paludinosus; these were grown to over 200 g in six months, with a feed conversion ratio (weight of food given : wet weight of fish harvested) of 1.7.

Production statistics: none yet available.

Where farmed: Region - West Africa, FAO Area Africa-01, Inland

Countries: Benin, Côte d’Ivoire, Ghana, Nigeria and Sénégal, and probably others in this region, all on a limited scale.

Climate and Environmental Tolerance: tropics; natural temperature range 17-33°C; cannot reproduce below 20 to 23°C; wide salinity tolerance, 0-45 ppt, prefers 10-15 ppt; relatively acid-tolerant, grows and reproduces at pH 3.5 to 5.2 over acid sulfate soils (Campbell 1987; Trewavas 1983); information is lacking on lethal limits; these and tolerance ranges probably vary among subspecies and populations.

Current farming methods: Hatchery methods still under development; reproduces readily in enclosures, ponds and tanks; monthly fry (1 g) production of 200,000 to 250,000 achieved from a raceway system; a spawning female produces 200-900 eggs; size at first sexual maturity is variable among populations, from 4.0-4.5 cm SL for stunted populations to 13.4 cm; male parent normally mouthbroods the eggs and larvae; fry feed mainly on plankton (progressively more zoo- than phytoplankton) detritus and aquatic larvae; diet thereafter is omnivorous, including detritus (Pauly et al. 1988 quantified this detritivory and compared growth parameters), plankton, invertebrates and plant material, especially periphyton; fry readily accept feeds based on cereal bran, peanut cake, fishmeal and vitamins (Campbell 1987).

Grow-out methods are under development for ponds, cage and enclosure systems; adults readily accept agricultural by-products and feeds in powdered, mash or pellet form (Campbell 1987).

Processing and Marketing: No summary information available; assume main products are fresh, whole, ungutted fish or whole smoked or dried fish; value-added products, such as fillets, are expected if intensive systems are developed; large fish (>350g) and value-added products could enter global tilapia markets; smaller fish (ca 50 g) are important in domestic markets.

Likely Future Trends: Could become important in aquaculture in West Africa, if systems under development fulfill early promise; of interest for brackish water aquaculture in other regions because of its wide salinity tolerance; for this, adequate appraisals of possible environmental impacts are essential prior to introductions given former bad experiences with tilapia introductions (Oreochromis mossambicus); thorough documentation of the characteristics of different subspecies and populations, and their conservation for use in breeding programs, are needed.

References:

Agnèse, J.F. 1996. La recherche au service du développement: l’exemple du programme GENETICS./Research for development: the GENETICS programme. EC Fisheries Cooperation Bulletin 9(3):15-17. (In French and English).

Campbell, D. 1987. A review of the culture of Sarotherodon melanotheron in West Africa. UNDP/FAO African Regional Aquaculture Centre, Aluu, Port Harcourt, Nigeria. Working Paper ARAC/87/WP/5, 20 p.

Gilles, S., J.B. Amon-Kothias and J.-F. Agnèse. 1998. Comparison of brackishwater growth performances of Sarotherodon melanotheron (Cichlidae) from three West African population, p. 199-210. In J.-F. Agnèse (ed.) Genetics and aquaculture in Africa. ORSTOM, Africa 326 p.

Hem, S. and J.L.B. Avit. 1996. Acadja-enclos: un système d’exploitation piscicole extensive en Côte d’Ivoire, p. 48-55. In R.S.V. Pullin, J. Lazard, M. Legendre, J.B. Amon-Kothias et D. Pauly (éds.). Le Troisième Symposium International sur le Tilapia en Aquaculture. ICLARM Conf. Proc. 41, 630 p. [English version available in p. 45-53 of the same conference proceedings series].

Pauly, D., J. Moreau and M.L. Palomares. 1988. Detritus and energy consumption and conversion efficiency of Sarotherodon melanotheron (Cichlidae) in a West African lagoon. J. Appl. Ichthyol. 4:190-193.

Trewavas, E. 1983. Tilapiine fishes of the genera Sarotherodon, Oreochromis and Danakilia. British Museum (Natural History), London. 583 p.

Roger S.V. Pullin