Aspects of the Biology of Clarias Gariepinus in Anambra River Basin. 1. Oocyte Diameter, Fecundity and Sex Ratio

Abstract

Aspects of the reproductive biology of the African catfish, C. gariepinus Burchell, caught from Anambra River Basin, Nigeria were investigated. The oocyte diameter had bimodal size distribution, suggesting the possibility of multiple spawning cycles in a year. Fecundity was between 9,000 and 25,000 ova and was linearly related to fish ovarian weight, gonadosomatic index, fish weight and standard length. The 1:1.07 mean yearly ratio of male: female was not statistically significant (P > 0 05).