Abstract
This study, conducted from January to December 2023, investigated the reproductive biology of Coilia dussumieri in the mid-southern coast of Bangladesh. The length-weight relationship indicates a positive allometric growth (b >3) pattern within the species. The highest fecundity (10780) was observed in a fish with a total length of 14.89 cm, body weight of 11.64g and gonad weight of 1.19 g. The lowest fecundity (1040) was found in a fish with a total length of 10.95 cm, body weight of 5.9 g and gonad weight of 0.1 g. Fecundity showed a linear relationship with body weight, total length, and gonad weight. The monthly variation of GSI values occurred in August to March, with September having the highest GSI value. The findings of the present study would be very helpful for further research and provide valuable information for sustainable management and conservation of the species in the coastal regions of Bangladesh.