Effects of short-term management stress and ACTH injections on plasma cortisol levels in cultured white sturgeon, Acipenser transmontanus

General management practices including capture, handling and transportation in fish hatcheries can induce a stress response indicated by a plasma cortisol increase in many species. However, this phenomenon is not well established in cultured white sturgeon ( Acipenser transmontanus). We determined resting levels of cortisol and the cortisol responses to two management stressors and to exogenous adrenocorticotropic hormone (ACTH 1–24) injections in cannulated mature male white sturgeon. Mean resting cortisol level was 8.6 ng/ml and ranged over 5.8–12.8 ng/ml through a 22-h period. Water reduction and transportation+handling stressors elicited significant cortisol increases above pre-stress and post-stress levels. Exogenous ACTH 1–24 injections of 0.5 and 5.0 μM caused dose-dependent peak cortisol increases above those produced by either the water reduction or transportation+handling stressors.