Serum Cortisol Levels in Channel Catfish, from Production Ponds

Abstract

Serum cortisol levels were measured in pond cultured channel catfish to determine if time of year or stocking density influenced this serum parameter. A significant effect of sampling month was found on cortisol concentration with values obtained in September and December being the highest. Stocking density also significantly influenced coritsol concentration with 9,800 fish/ha having the lowest mean cortisol concentration when compared to densities of 14,800/ha and 19,800/ha. Care must be exercised when fish are sampled due to the rapidity with which cortisol concentrations will change in response to stress.