Reproductive Biology of Sarotherodon melanotheron in the Dominli Lagoon, Ghana

Condition indices, sex ratio, length at sexual maturity, fecundity and gonadosomatic indices of Sarotherodon melanotheron in the Dominli lagoon were investigated with the aim of providing basic information on the reproductive biology of the species for fisheries management and considerable aquaculture development in the study area. Condition indices which varied from 3.42 to 4.53 indicated that the fish were in good conditions. Sex ratio of 1:1.5 in favour of the females and length at first sexual maturity (Lm) of 13.4 cm SL were determined for the fish. The fecundity ranged from 97 to 379 eggs with a mean of 206 eggs suggesting the less-fecund nature of the fish in the lagoon. The presence of mature gonads encountered throughout the study is a suggestive continuous recruitment into the population. S. melanotheron which sexually matures at a larger size necessitates an upward review of the current minimum mesh size (5.1 cm) of fishing nets used in the lagoon so as to allow the fish to spawn at least once in its lifetime prior to exploitation.