A Proposed Standard Weight Equation for Blue Suckers

Abstract

Length and weight data were obtained from 46 populations of blue suckers Cycleptus elongatus (N = 8,811 fish) across the species' geographic distribution to develop a standard weight (W _s) equation. The W _s 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 log₁₀ W _s = −2.980 + 0.977 log₁₀TL + 0.461(log₁₀TL)², where W _s is expressed in grams and TL is expressed in millimeters. The proposed English-equivalent 75th-percentile quadratic equation is log₁₀ W _s = −3.354 + 2.273 log₁₀TL + 0.461(log₁₀TL)², where W _s is expressed in pounds and TL is expressed in inches. The 75th-percentile linear equation (metric units) is log₁₀ W _s = −6.301 + 3.456 log₁₀TL, and the proposed English equivalent is log₁₀ W _s = −4.104 + 3.456 log₁₀TL.