Evaluation of bioelectrical impedance analysis methods for use on Channel Catfish

Abstract

Assessment of body composition is an accurate measure of condition. This study evaluates bioelectrical impedance analysis (BIA) methods for Channel Catfish Ictalurus punctatus. BIA shows promise as a quick, inexpensive, and non-lethal technique to estimate body composition. Models were developed by correlating BIA measures to total body water (TBW). The seven anatomical locations where measures were taken had a significant influence on predictive ability of models. Dorsal-lateral measurements were highly correlated with volumetric resistance in series and had the highest predictive ability for TBW (R2=0.9651 and 0.9816). TBW converted to percent dry mass (%DM) was used as a proxy for fat and protein. Significant relations were found between %DM and percent fat (R2=0.8319) as well as percent protein (R2=0.7033). Temperature had a significant negative effect on BIA measures. Measures of wet weight and total length also had significant relations to TBW, therefore, further analysis of BIA models is necessary.