Fishery and biological traits of obtuse barracuda Sphyraena obtusata (Cuvier, 1829) off south-west coast of India

Abstract

Aim: The present study was conducted to investigate the fishery, diet composition and reproductive aspects of obtuse barracuda landed in Karnataka, south-west coast of India. Methodology: Feeding and reproductive traits of 1229 samples (638 males and 591 females) of S. obtusata was studied for a period of five years. The index of relative importance (IRI) was determined for each diet component in the stomach. Reproductive aspects such as maturity stages, gonadosomatic index and fecundity were investigated. Results: The most predominant prey item in terms of frequency of occurrence (93.1%), number (91.4%), weight (93.2%), IRI (3615.5) and also % IRI (98.5%) was fishes. Crustaceans and cephalopods were noticed less frequently and were represented by shrimps and Loligo sp. The estimated length at first maturity for male and female fishes was 20.5 and 21.3 cm, respectively. Higher GSI values were observed during post monsoon (October-November) followed by summer pre monsoon (April-May) season in both males and females, indicating two peak spawning periods. Interpretation: The comprehensive study on major biological characteristics of Sphyraena obtusata could be useful for developing appropriate management strategies for conservation and judicious exploitation of this commercially important resource.