Length-weight and length-length relationships of freshwater wild catfish <i>Mystus bleekeri</i> from Nala Daik, Sialkot, Pakistan

Abstract

Length-weight (LWR) and length-length relationships (LLR) were determined for a freshwater catfish Mystus bleekeri (Day, 1877) collected from Nala Daik, Sialkot, Pakistan. A total of 105 specimens (56 males; 49 females) were collected from February to March, 2010. Each specimen was weighed (g) and measured (cm). The total length of specimens studied ranged from 5.5 to 7.8 cm. Linear regression analysis was used, first to compute the degree of relationship between length and weight and then among total (TL), standard (SL) and fork lengths (FL). LWR exhibited a highly significant correlation (P < 0.001). The overall value of the exponent of LWR (b = 2.62) suggested negative allometric growth. Results for LLRs indicated that these are highly correlated (P < 0.001). Furthermore, the first reference for separate male, female and combined sex of length-weight and length-length relationships for Mystus bleekeri was provided.

Key words: Mystus bleekeri, length-weight relationship, length-length relationship, predictive equations.