Comparative Study of Reproductive Traits in Gangetic Hairfin Anchovy, Setipinna phasa (Hamilton, 1822) from Estuarine and Freshwater Ecosystems

Abstract

The Gangetic hairfin anchovy, Setipinna phasa (Hamilton, 1822) were collected from river Ganga (Kanpur) and Hooghly estuary (Kolkata) to study the comparative reproductive traits (sex ratio, spawning season, gonado-somatic index, fecundity and egg diameter). Female outnumbered the male in the population of river Ganga but it was non-significant in the population of the estuary. Five maturity stages were identified in males and females of the fish of both ecosystems. Occurrence of multimodal (immature, maturing and mature) and uni-modal (matured) type of ova in the ovary of the fish of Hooghly estuary and river Ganga respectively and the values of gonado-somatic index confirmed the double and single spawning in a year in the fish in estuary and river respectively. The absolute fecundity was found to be higher in the fish of river Ganga compared to that of the estuary (P < 0.05). Linear and positive correlations between fecundity and the total length, body weight, ovary length and ovary weight were noted in the fish of both ecosystems (R2 > 0.90). The present study provides the comparative account of the reproductive and spawning strategies of S. phasa for the first time in favour of the proper management and conservation of the fish.