The present study reports length-weight relationship and biological aspects of Thryssa setirostris from Thoothukudi coastal waters during the period September 2016 to July 2017. T. setirostris is an important trawl by-catch landing at Thoothukudi. The largest size observed for T. setirostris was 14.5 cm total length, weighing 22.74 g. The value of growth constant a= 0.0107 and b= 2.8801. The overall ratio of males and females was 1:1. Minimum size of maturity of the species was 11.3 cm and more than 50% of species were found to be mature at 11.5 cm. Fecundity ranged from 3057 to 16395 ova in fish measuring 11.4 to 13.9 cm in total length respectively. The von Bertalanffy growth parameters L∞, K and t0 were 15.02 cm, 1.40 and -0.1365 respectively. The estimated total instantaneous mortality co-efficient (Z) of T. setirostris was 4.60 and the fishing mortality co-efficient (F) was 1.83. The species is under-exploited along the Thoothukudi coast.

Thryssa setirostris, age, growth and mortality parameter, reproductive biology