Evaluation of practical diets with three levels of protein and lipids for juvenile Hemichromis fasciatus Peters (Teleostei, Cichlidae)

Abstract

Three experimental diets, containing 29, 37 and 44% protein levels, with respectively 20.0, 20.6 and 21 kJ/g crude energy contents were prepared and their effect on growth and feed utilisation were evaluated for juveniles (1.2 g) of Hemichromis fasciatus, a cichlid commonly used as “police” fish in tilapia ponds of sub-saharian countries. The significantly highest growth (SGR=1.90) and protein retention efficiency (PRE=35.3%) were obtained in outdoor rearing structures with the 29% protein diet. However, no significant difference was found for feed conversion ratio and energy retention efficiency. Most of the parameters tended to decrease with increasing dietary protein and lipid level. As a consequence, although adults of Hemichromis seem to depend essentially on tilapia fry for their feeding, the present study suggests that a
dietary protein close to 29% with a P / E ratio of about 15 mg protein per kJ energy is better for H. fasciatus juveniles than higher levels. This trend meets what is observed with some other cichlids as the Nile tilapia. A design using lower ranges of dietary protein and lipid needs to be investigated.

Key words: Hemichromis, protein diets, fish feeding, Cameroon