Abstract

• The reproductive biology of Harpadon nehereus from Mon coastal water was investigated during May (2019) to April (2020). H. nehereus have a prolonged spawning season with two peaks during May to June and December to January. GSI showed peak values in May (4.16), June (5.16), December (4.83) and January (5.69) in female. The Kn values ranged from 0.989 (August) to 1.004 (October) in male and 0.998 (July) to 1.027 (December) in female. The overall sex ratio (1:0.66) showed significant difference at 5% (p<0.05) level and males outnumbered females. The length at first maturity of females was estimated as an average of 230 mm. The fecundity varied between 23,625 and 117,498 with an average fecundity of 55054 ova. The fecundity indicated higher relationship with ovary weight (r = 0.934) rather than total length (r = 0.724) and body weight (r = 0.713). The mature ovaries (from stage IV to VI) of H. nehereus contained mature ova which are distinctly separated from the immature stock.