Preliminary study on the domestication of broodstock of an ornamental aquarium fish, <i>Synodontis obesus</i> (Teleostei: Mochokidae) in concrete tanks

Abstract

The state of ornamental aquarium fish export trade in Cameroon is largely undeveloped. This is due mainly to lack of technical know-how concerning domestication and breeding. Synodontis obesus broodfish has been domesticated for six months in concrete tanks located at Buea, Cameroon using local food materials and plankton species, without fertilization. The broodfish were domesticated under temperatures ranging from 20.4-24°C, pH, (6.6-10.0); dissolved oxygen, (0.75-11.0mg/l) and electrical conductivity, (40.5-523 µS/cm) in the experimental concrete tanks. Dissolved oxygen concentration was enhanced using an air blower. The average rate of aeration was 3.6 hours per day using an automatic timing device. The results also revealed that the levels of dissolved oxygen concentration were higher between the hours of 1200 and 1700 (5.2-6.0mg/l) even without aeration. Primary productivity was considerably increased by the aeration of the tanks at 3.6 h day^-1. Brood fish were fed a mixture of 375g of tapioca, 100g of crushed boiled cabbage and 150g of crushed dried crayfish. The broodstock of this ornamental aquarium fish species may not survive in concrete tanks without the right type and quantity of supplementary food.

Keywords: ornamental, aquarium, experimental tanks, broodstock, Synodontis obesus, domestication

Tropical Freshwater Biology 2003/2004 Vol. 12/13: 137-153