Reproduction and Breeding Cycle of Some Commercially Important Fish Species in Gbedikere Lake, Bassa, Kogi State, Nigeria

Abstract

This study was carried out to examin the reproduction and breeding cycle of some commercially important fish species in Gbedikere Lake, between July and December, 2007. 553 fish samples comprising Gymnarchus niloticus, Clarias gariepinus, Tilapia zilli and Oreochromis niloticus were obtained for the study. Samples were sexed, measured and weighed for meristic and morphometric parameters. Egg diameter was determined using ocular lens diameter and stage micrometer. Fecundity in each ovary was determined by direct enumeration using digital counter and recorded. The result showed that the male G. niloticus had 102.0 cm length and 12.5 g weight and the females had 86.0 cm length and 13.6 g as size at first maturity with a corresponding mean standard length at entry with 2 mesh net of 18.50 cm while 12.0 cm length/17.0 g weight, 17.0 cm length/4.6 g weight with 19.0 cm as corresponding mean standard length at entry with 2 meshes was obtained for Clarias gariepinus. Tilapia zilli and Oreochromis niloticus had 34.3 cm (length)/17.0 g (weight), 17.0 cm length/4.6 g weight with 19.0 cm; 34.1 cm length/6.0 g weight, 20.5 cm length/4.3 g weight with 10.80 cm length respectively for males and females.