A Proposed Standard Weight Equation for Blue Suckers

Length and weight data were obtained from 46 populations of blue suckers Cycleptus elongatits (N = 8.811 fish) across the species' geographic distribution to develop a standard weight (W(s)) equation. The W, equation was derived using the empirical percentile technique applied to fish between 240 and 809 mm total length (TL). We calculated a quadratic model and a linear model to derive W(s). The proposed 75th-percentile quadratic equation (metric units) is log(10)W(s)=-2.980+0.977 log(10)TL + 0.461(log(10)TL)(2), where W(s) is expressed in grants and TL is expressed in millimeters. The proposed English-equivalent 75th-percentile quadratic equation is log(10)W(s) = -3.354 + 2.273 log(10)TL + 0.461(log(10)TL)(2), where W(s) is expressed in pounds and TL is expressed in inches. The 75th-percentile linear equation (metric units) is log(10)W(s) = -6.301 + 3.456 log,,TL, and the proposed English equivalent is log(10)W(s) = -4.104 + 3.456 log(10)TL.