Evaluation of a Nondestructive Method for Determining Body Composition of White River Crayfish Procambarus acutus

Abstract

A nondestructive method for determining body composition by measuring total body electrical conductivity (TOBEC) was evaluated with 36 male and 36 female white river crayfish Procambarus acutus, ranging from 82 to 122 mm total length (TL) and from 16.62 to 67.11 g wet weight (WW). Significant relationship with an R ² of 0.999 was observed using TOBEC and WW for lean body mass (LBM), whereas WW, TL, or a combination of these variables were significantly correlated with protein (R ² = 0.914), ash (R ² = 0.902), and water content (R ² = 0.978). The correlation coefficient was the lowest for lipid content (R ² = 0.652) using TOBEC and WW. The predictive models for LBM, lipid, and ash were significantly different for male and female crayfish. Relative body composition for a standard-size female crayfish was 3.48% lipid and 9.71% ash compared with 1.91% lipid and 11.85% ash for a male. Analysis of an independent group of eight male and female crayfish demonstrated that TOBEC and WW jointly were reliable indicators of LBM and that total lipid content of crayfish could be calculated as the difference between WW and LBM.