Length–weight and length-length relationships of a silurid catfish, Ompok bimaculatus from Chenab River, Multan, Pakistan

Abstract

The present work reports the length–weight relationship (LWR) and length-length relationships (LLRs) for Ompok bimaculatus, collected from the Chenab River, Multan, Pakistan during May, 2020. Mean (±SE) body weight (W), total length (TL), standard length, fork length, head length and body girth of the studied samples of O. bimaculatus were found 28.25±2.51g, 17.70±0.50 cm, 15.54±0.45 cm, 16.37±0.47 cm, 3.29±0.10 cm and 6.73±0.20 cm, respectively. Whereas, mean (±SE) values of dorsal fin length, pectoral fin length, pelvic fin length, anal fin length and caudal fin length were found 2.06±0.06, 2.14±0.07, 1.04±0.03, 9.29±0.27 and 2.16±0.06cm, respectively. All the regressions for LWR and LLRs were found highly significant (P<0.001). LWR (W = a TLb) found W = -2.3916TL3.03 for O. bimaculatus indicating isometric pattern of growth, with coefficient of determination (r2) value being 0.981. Results of LLRs indicate that all the studied morphometric length parameters represented isometric pattern of growth, except for body girth, pelvic fin length and caudal fin length which showed negative allometric pattern of growth with an increase in TL for wild O. bimaculatus. The findings of present work could be helpful to fill the knowledge gap, and for conservationand sustainable management of the investigatedcatfish species.