Biology of the Bombayduck Harpadon nehereus (Hamilton, 1822) from the north-eastern Arabian Sea, India

Abstract

The Bombayduck Harpadon nehereus (Hamilton, 1822) is a common species and majorcontributor to the fishery in the northern Arabian Sea. The biology of H. nehereus, exploitedby set bagnets (SBN, dol netters) and trawlers from the northern Arabian Sea coast of India(Gujarat and Maharashtra) was investigated during 2014 to 2019. Fishes with a size rangeof 30-408 mm mainly contributed to the fish landing. The sex ratio (male: female) was 1:1.5.Length at maturity (Lm) for females was estimated at 207 mm TL. Mature ovaries containedova of all maturity stages indicating the species to be a continuous spawner. The absolutefecundity ranged from 23,444 to 1,34,432 eggs per fish and relative fecundity ranged from235-430 eggs g-1. The gonadosomatic index and monthly maturity stages suggested thatH. nehereus is a continuous spawner with peaks occurring from February to April. The ‘b’value in the length-weight relationship was 3.31 showing a positive allometric growth. Thediet analysis showed H. nehereus to be a highly carnivorous predator which fed mainly oncrustaceans (Index of Relative Importance, IRI = 82.7%) followed by teleosts (17.3%). Thepresent article discusses the biology of H. nehereus in the north-eastern Arabian Sea. Keywords:Biology, Bombayduck, Fisheries, Harpadon nehereus,Indian Ocean, Trophic level