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

Biology of Bombay duck in north eastern Arabian Sea

Abstract

The Bombayduck Harpadon nehereus (Hamilton, 1822) is a common species and major
contributor to the fishery in the northern Arabian Sea. The biology of H. nehereus, exploited
by 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 range
of 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 contained
ova of all maturity stages indicating the species to be a continuous spawner. The absolute
fecundity ranged from 23,444 to 1,34,432 eggs per fish and relative fecundity ranged from
235-430 eggs g-1. The gonadosomatic index and monthly maturity stages suggested that
H. 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. The
diet analysis showed H. nehereus to be a highly carnivorous predator which fed mainly on
crustaceans (Index of Relative Importance, IRI = 82.7%) followed by teleosts (17.3%). The
present article discusses the biology of H. nehereus in the north-eastern Arabian Sea.

Keywords:
Biology, Bombayduck, Fisheries, Harpadon nehereus,
Indian Ocean, Trophic level