Temporal changes in feeding and bio-indices of Polynemus paradiseus Linnaeus, 1758 occurring in Hooghly-Matlah estuary, West Bengal

Abstract

Temporal changes in feeding and bio-indices of Polynemus paradiseus were studied at selected stretches of Hooghly-Matlah estuary for a period of eight months (December to July). It indicated that the fish mainly feeds on shrimps, fishes, and insects. The highest amount of shrimps (45.49%) was recorded in December and those of fishes (16.10%) during June and copepods and insects (7.31%) in July. The presence of a considerable amount of small fishes, insects and crustaceans in gut contents indicated carnivore-feeding habits of fish. Adult size of the species mainly feeds on shrimps and fishes whereas juveniles feed on shrimps, copepods, insects, and zoobenthos. Gastro-somatic index (GaSI) was maximum during March and April and minimum during June and December in fish. The monthly mean gonado-somatic index (GSI) values varied from 0.74 (December) to 1.32 (June) in males and 0.82 (December) to 5.44 (June) for female fish, respectively.