Fishery and biology of threadfin bream,Nemipterus mesoprion from Mangalore-Malpe

The landings of threadfin breams recorded 8 fold increase during 1989 – 1998 period while the catch rate showed three-fold increase. Maximum catch and catch rate was observed in September-October. N. mesoprion has taken over the place of N. japonicus by forming 64% of the fishery. The mean size increased from 127 to 164 mm. Significant differences were found in the length-weight relationship between sexes. Males outnumbered females in all the months and the overall sex ratio was M-1: F-0.70, which significantly departs from the expected 1:1 ratio. The minimum size at first maturity of males was 145 mm and female, 125 mm. Spawning was prolonged with peak during August-November. The peak spawning indicated by GSI, is in general agreement with the percentage occurrence of maturity stages in different months. The fecundity ranged from 7,444 to 49,689 eggs. The stomach content analysis revealed that the species feed mainly on crustaceans.