Reproductive Biology of the Blackchin Tilapia Coptodon guineensis in the Niamone-Kalounaye MPA, Casamance, Senegal

The blackchin tilapia Coptodon guineensis is a highly prized fish species in Senegal. It is one of the most sought-after food species. The species is heavily caught by local fishermen in the Casamance estuary. This study was carried out in order to obtain basic scientific information on the reproductive parameters of the tilapia Coptodon guineensis in the Marine Protected Area of Niamone-Kalounayes. The individuals studied were sampled over a one-year period from June 2021 to May 2022 using a 250m long beach seine with a 25mm mesh size. Overall, a total of 338 individuals of Coptodon guineensis (195 males and 143 females) were sampled. Thus, the sex ratio obtained was in favor of males (1:0.7). The study shows a significant monthly change in the gonadosomatic index. The species has two breeding periods, a dry season in April, May and June with peak breeding in May and a second breeding period at the end of the rainy season in September and October. In the study area, males reach the size of first sexual maturity (Lm50) at a smaller size (11cm) compared to females (12cm). This study, considered the first of its kind in the area, is of crucial importance. The results will be used as a reference for a better management plan for the species in the MPA, but also to combat overfishing and fishing pressure that the species is suffering from in the area, especially in the Casamance estuary.