Development and Evaluation of a Standard Weight (Ws) Equation for Blue Catfish

Abstract Using a data set composed of 33 populations from six states, we employed the regression-line-percentile technique to develop a standard weight equation for blue catfish Ictalurus furcatus and validated it with an independent data set composed of 43 populations from 10 states. The equation is log10Ws = −6.067 + 3.400 log10TL, where Ws is standard weight in grams and TL is total length in millimeters. The English-unit equivalent (pounds and inches) is log10Ws = −3.950 + 3.400 log10TL. The equation is valid for blue catfish 160 mm (approximately 6 in) TL and longer. Relative weight (Wr) values computed with this equation did not exhibit any systematic length bias.