Use of Bioelectric Impedance Analysis to Assess Total-Body Condition and Predict Energy Density in Juvenile Atlantic Croaker

Abstract

Abstract Bioelectric impedance analysis (BIA) uses the conductive properties of biological tissues to provide whole-body resistance (R) and reactance (Xc ) data through direct measurements of intracellular and extracellular water content. The application of BIA to fish remains relatively novel, and the relationship between condition and impedance is not fully understood. We sought to test the efficacy of BIA in assessing total-body condition and energy content in juvenile fish. We present results from a laboratory tank experiment using juvenile Atlantic croaker Micropogonias undulatus to investigate the BIA-condition relationship and compare BIA with traditional condition measures (i.e., relative condition and energy-content analysis). Atlantic croaker were held in large recirculation tanks and subjected to either a starvation or ad libitum feeding treatment for 45 d. Relative condition, energy content, phase angle, and the composition index all showed significant differences between treatments. However, ...