Aspect of Reproductive Biology of Chrysichthys nigrodigitatus (Lacepède 1803) in Asejire Reservoir, Nigeria

Background and Objective: Knowledge of fish reproduction is crucial to survival and abundance for sustainable use. Thus, a study on the sex ratio, size structure and gonad somatic index (GSI) of Chrysichthys nigrodigitatus in Asejire Reservoir was conducted in Asejire Reservoir, Nigeria to provide information on aspects of reproductive biology for sustainable management. Materials and Methods: The 251 samples of Chrysichthys nigrodigitatus were randomly collected from fishers’ catch for seven months covering the wet and dry seasons of 2022 to assess sex ratio, size structure and gonadosomatic indices following standard procedures. Data generated were analysed using descriptive and inferential statistics at α_0.05. Results: Samples examined had a joint sex ratio of 1:1.5 indicating a more dominant female population across both seasons. The GSI value ranged from 0.53-9.75 (wet) and 0.31-10.69 (dry) while the correlation coefficient between the GSI and body weight was 0.45 (wet) and 0.20 (dry). The result revealed a positive correlation across all relationships except between the GSI and weight in the dry season. Conclusion: The study provides crucial reproductive insights for managing Chrysichthys nigrodigitatus and suggests exploring its aquaculture potential through additional research.