Behavioral and metabolic aspects of low temperature dormancy in the brown bullhead,Ictalurus nebulosus

摘要: 1. Behavioral and physiological measurements were made during the winter at low temperatures to evaluate cold temperature dormancy in brown bullhead. 2. At 17°C when slowly cooled 3°C bullheads often buried themselves mud (Fig. 1). Animals not immobilized would emerge from following a disturbance. 3. No readjustment of thermoregulatory mechanisms was seen acclimatized placed thermal gradient that cooled. At end 6–7 h, always became quiescent warmest portion available (11–13°C)-(Fig. 2). 4. Spontaneous activity oxygen uptake measured, acclimation temperature, for animals acclimated 3–17°C 2°C intervals. 5. Spontaneous an annular tank showed high degree compensation between 5 17°C. much less spontaneous exceptionally initial hyperactive period placement 3). 6. When measured with closed system technique which involved very slight disturbance, large increases magnitude variability occurred higher temperatures. These if sleeping fish open 4). 7. Overwintering this species may simply involve increase time spent burrowed asleep.