Reproductive potential of Nile tilapia (Oreochromis niloticus Linnaeus, 1757) in the Golinga reservoir in Ghana

Abstract

The study investigated the reproductive potential of Oreochromis niloticus by assessing the developmental stages of gonads, the fecundity and the environmental conditions (water quality) in which the fish lives. It was conducted for six months (November 2006-April 2007) with fortnight sampling of fish. Of a total of 115 fishes sampled, males were 42 and females 73. Of the 73 females 14 were gravid. For the stages of gonad development, immature (white coloured gonads) were 7.14%, maturing (yellow coloured gonads) represented 7.14%, ripe (deep green coloured gonads) was 50% and those spent (red, flaccid coloured gonads) were 35.7%. Fecundity of the fish ranged from 137-250 oocytes/eggs. Gonado-somatic index (4.49) and condition factor (4.07) were highest in April. The pattern of gonad development indicated that spawning in the species was not synchronized, however, spawning peaked in April. The water quality parameters measured were within the tolerable limits for growth of the fish.