Feeding dynamics and reproductive biology of the obtuse barracuda Sphyraena obtusata (Cuvier, 1829) from Ratnagiri, central west coast of India

Abstract

The obtuse barracuda Sphyraena obtusata (Cuvier, 1829) is a commercially important food
fish belonging to the family Sphyraenidae and landed mostly as trawl bycatch along Ratnagiri.
Investigations were carried out on the species with respect to the length-weight relationship,
condition factor, morphometrics, feeding and reproductive biology. The length-weight
relationship showed positive allometric growth in males, females and pooled individuals. All
morphometric measurements showed a high degree of correlation with total length. The gut
content analysis revealed S. obtusata to be a carnivore fish feeding mainly on fish juveniles,
fish scales, crustaceans and cephalopod appendages. The male:female sex ratio was found
to be 1:0.90. Gonado-somatic index (GSI), maturity and ova diameter studies indicated that
S. obtusata has a prolonged spawning season with individuals spawning twice in a season.
Absolute fecundity ranged from 68355 to 310615 eggs with an average of 137783 eggs. The
mean length at sexual maturity for females was found to be 22.92 cm.

Keywords:
Carnivorous fish, Fish biology, Life history,
Trophodynamics, Tropical fisheries