Gonadal Maturation and Fecundity of Schilbe mystus (Linnaeus, 1758) from River Taraba at Tella, Nigeria

Abstract

African butter catfish (Schilbe mystus) is a freshwater species widely distributed across inland waters in Africa, including rivers, lakes, and floodplains. The study was conducted in the laboratory of the Department of Zoology at Taraba State University, Jalingo, to investigate the reproductive biology of Schilbe mystus from River Taraba at Tella, Nigeria, to inform sustainable fisheries management and conservation efforts. A total of 300 specimens were collected monthly over 12 months from January to December 2024. Data on sex ratio, gonadosomatic index (GSI), maturity stages, and fecundity were analyzed. The sex ratio (1.1:1; female: male) did not significantly deviate from the expected 1:1 ratio (χ² = 1.067, p > 0.05). GSI values peaked between March and July, indicating the main spawning season occurs during the early rainy season. Five gonadal maturity stages were identified in females, with ripe ovaries most common from April to June. Fecundity ranged from 3,200 to 22,400 eggs per female, and showed a strong positive correlation with total length (r = 0.78, p < 0.01) and body weight (r = 0.81, p < 0.01). These findings indicate that S. mystus is a multiple spawner with a seasonal breeding pattern, underscoring the need to regulate fishing pressure during peak reproductive periods.