Length at First Sexual Maturity of Oreochromis Niloticus in Ekoli Creek, Bayelsa State, Nigeria

This study investigated the length at first sexual maturity (Lm50) of Oreochromis niloticus in Ekoli Creek, Bayelsa State, Nigeria. Fish samples were collected monthly from artisanal fishers from August 2023 to April 2024. A total of 324 fish specimens comprising 145 females and 179 males were examined. Gonadal maturity stages were classified into immature (stages 0–2) and mature (stages 3–6) following standard reproductive assessment procedures (Mous et al., 1995). Length at first sexual maturity (Lm50) was estimated using logistic regression analysis as described by Sparre and Venema (1998). Results showed that female O. niloticus attained first sexual maturity at 23.89 cm, while males attained maturity at 54.60 cm. The findings indicate that females matured earlier than males. This information provides baseline data for fisheries management and conservation of Nile tilapia in Ekoli Creek.