Population dynamics of catfish Sperata seenghala Sykes, 1839 with special reference to physico-chemical water quality parameters in Gomati River of Tripura

Abstract

The present study analyses the population dynamics of Sperata seenghala Sykes, 1839 by evaluating sex ratio, length–weight relationship, and reproductive traits, with special reference to the physico-chemical parameters of water in the upper and lower reaches of the Gomati River in Tripura, Northeast India. A total of 357 specimens were examined, with females predominating over males (67.5:32.5). Significant length–weight relationships were observed across different developmental stages, with females generally attaining greater size than males. Gonadal development progressed from February to July, with peak GSI and spawning activity occurring in July, while fecundity ranged from approximately 10,000 to 22,000 eggs per fish. Water-quality conditions were comparatively favourable in the upper reach, which supported higher fish abundance, and several physicochemical parameters showed significant associations with population density.The study highlights the immediate need for conservation measures, such as the closure of unscientific sand mining, seasonal fishing closures, and the declaration of some sites as no-fishing zones, to ensure the long-term sustainability of this fish species in the Gomati River of Tripura.