Abstract
This study investigated the reproductive parameters of Somileptes gongota (Balachata), a near-threatened freshwater species in Bangladesh, with the aim of establishing baseline information necessary for its conservation and captive propagation. Broodfish were collected from the Chikli River and adjacent local sources and reared from January to December 2019 at the Bangladesh Fisheries Research Institute (BFRI), Freshwater Sub-Station, Saidpur. Monthly sex ratio and gonadosomatic index (GSI) were assessed to determine reproductive seasonality and maturity patterns. The annual sex ratio revealed slight male dominance (female: male = 1:0.94), with significant deviations (p < 0.05) observed in August, October, and December. Female GSI values increased steadily from January, reached a peak of 13.55 in May, and declined thereafter, indicating a distinct spawning season extending from April to June. Absolute fecundity ranged from 8,960 ± 1,635 eggs in the smallest females (7.25 ± 0.33 g) to 42,760 ± 1,820 eggs in the largest females (17.40 ± 1.30 g), showing a strong positive correlation with body weight, gonad weight, and GSI. The findings confirm that S. gongota is a single-spawning species with a well-defined reproductive cycle. Successful evaluation of its reproductive biology provides critical information required for developing induced breeding protocols and conserving this declining species in natural and captive conditions.