Growth and feeding ecology with prey preference of Longarm mullet, Valamugil cunnesius (Valenciennes, 1836) in brackishwater traditional impoundments of Sundarban, India

Abstract

The present study was conducted to assess fish growth, feeding ecology with prey preferences of Longarm mullet (Valamugil cunnesius) in brackish water traditional impoundments for 8 months during July, 2015 to March, 2016. Estuarine brackish water (18.68 ppt) containing seeds were entered and water was exchanged (20-30%) every lunar cycle through bamboo screens. Mullets were grown from 1.27±0.99 g (4.8±0.51cm) to 58.50±3.95 g (16.8±0.75cm).The fishes showed isometric growth (W=0.010TL3.025) and better Condition factor (K=1.07±0.05). Feeding intensity increased with increment of fish growth. Longarm mullet is an herbivorous fish grazing on phytoplankton and organic matter from the bottom sediment. According to the order of dominance, the major food items in stomach were Bacillariophyceae > Myxophyceae > Chlorophyceae > Dinoflagellets > Copepods > Polychaetes larvae > Crustacean larvae > Fish & prawn larvae. Prey preference analysis revealed that V. cunnesius actively selected Bacillariophyceae as most preferred food material followed by Myxophyceae  Chlorophyceae > Dinoflagellets.