The reproductive biology of Bombay duck, Harapdon nehereus off the Mumbai waters, Maharashtra India was investigated from August, 2023 to May,2025. In our study, 1012 specimens were sampled from inshore and offshore vessels operating dolnets and trawlers respectively. The length range of the sample collected ranged from 3-33cm respectively. We assessed the main biological parameters that describe reproductive potential: maturity, spawning seasonality, fish condition, and fecundity. The length at which 50% of for male and female population matures (L50) was estimated at 19.6 cm and 19.8 cm for males and females in total length respectively.
The main spawning season was observed in April to June and minor spawning in January but the presence of Gravid and ripe females was observed throughout the year. This can can be reflected with the presence of more juveniles in the catch during the succeeding months. The mean absolute fecundity for females 19–29 cm total length was estimated at 0.03 -1.1 lakh oocytes million oocytes. The use of histology gave the clear picture of asynchrony with unique morphology of the ova in the species was reported, provide an improved understanding of the reproductive cycle of Bombay duck in the Mumbai waters, Maharashtra, India.