Population Dynamics and Biology of Selected Catfishes Under the Family Bagaridae Order Siluriformes from Gomti River Eastern Uttar Pradesh

Abstract

newlineThe present study investigated the population parameters, food and feeding habits, and reproductive biology of four important bagrid catfish species, Sperata seenghala, Rita rita, Mystus cavasius and Mystus vittatus, inhabiting the Gomti River, Uttar Pradesh. All species exhibited negative allometric growth (b lt 3), with Land#8734; values120.7cm, 42cm, 31.5cm and 17.8cm and K values 0.13 yrand#8315;¹, 0.7/ yr-1. 1.3/yr-1 and 1.2/yr-1, respectively.All species exhibited throughout the year recruitment pattern. Natural mortality (M) values were 0.3, 0.68, 1.10 and 1.22, fishing mortality (F) values were 0.32,1.95, 4.05 and 4.07, total mortality (Z) values were 0.62, 2.63 ,5.15 and 5.29, andlength of max. exploitation ranges were 95-110cm, 10-15cm, 10-15cm and 7-11cm, respectively for speciesselected.Maximum exploitation rate (Emax) values were lesser than 0.5, indicating sustainable exploitation of all species. Length at first capture (L50) was found to be lower than length at first maturity (Lm) in S. seenghala, R. rita and M. cavasiuss, indicating recruitment overfishing. The Gut contents analysis revealed seasonal carnivory in all species. RGL values were 0.5 1.0, 0.5-2.5, 0.1-1.5 and 0.1-1, respectively with major food items observed through IP and IRI indices were insects, molluscs and annelids, confirming carnivorous feeding. The peak feeding and spawning were found to be coinciding between October and March as indicated by GaSI and GSI values. The absolute fecundity valueswere 31221-59296, 3187-21229, 2453-21860 and 3850-6597, and relative fecundity were 13.57-16.94, 13.28-55.86, 97.11-485.7 and 164.5-485.07,respectively in the species selected. The morphological development of gonads of species were in corroboration with the progression in GSI. Sex ratio was female biased in S. seenghala and M. vittatus, andmale-biased in M. cavasiuswhile nearly un-biased in R. rita. Our study suggested need for size-based harvest policies for sustainable fishery management of catfish species in Gomti River