PHYSIOLOGICAL STRESS IN STRIPED BASS - EFFECT OF ACCLIMATION TEMPERATURE

Physiological responses to acclimation temperature and confinement stress were studied in yearling striped bass, Morone saxatilis. Temperature significantly affected plasma cortisol, glucose, chloride, and hematocrit but not osmolality in fish acclimated to 5, 10, 16, 21, 25 and 30°C. Close confinement for 12 min in a net resulted in changes of these characteristics in some or all of these groups. Generally, plasma cortisol and glucose increased, and plasma chloride, osmolality, and hematocrit decreased due to net confinement, and returned toward resting levels after release from the net. The physiological changes during stress were greatest and the recovery from these changes was slowest at 5 and 30°C. Further, the quantitative response was least and the recovery most rapid in fish stressed at 10 and 16°C. Acclimating and moving striped bass within this temperature range should decrease stress-related responses and mortality and thus improve yield after stocking. © 1990.