The effect of temperature on the resting and post-exercise metabolic rates and aerobic metabolic scope in shortnose sturgeon Acipenser brevirostrum.

The effects of acclimation temperature (15, 20, 25 °C) on routine oxygen consumption and post-exercise maximal oxygen consumption rates (MO) were measured in juvenile shortnose sturgeon (Acipenser brevirostrum LeSueur, 1818). The routine MO of shortnose sturgeon increased significantly from 126.75 mg O h kg at 15 °C to 253.13 mg O h kg at 25 °C. The temperature coefficient (Q ) values of the routine metabolic rates ranged between 1.61 and 2.46, with the largest Q values occurring between 15 and 20 °C. The average post-exercise MO of all temperature groups increased to a peak value immediately following the exercise, with levels increasing about 2-fold among all temperature groups. The Q values for post-exercise MO ranged from 1.21 to 2.12, with the highest difference occurring between 15 and 20 °C. Post-exercise MO values of shortnose sturgeon in different temperature groups all decreased exponentially and statistically returned to pre-exercise (resting) levels by 30 min at 15 and 20 °C and by 60 min at 25 °C. The aerobic metabolic scope (post-exercise maximal MO-routine MO) increased to a maximum value ∼156 mg O h kg at intermediate experimental temperatures (i.e., 20 °C) and then decreased as the temperature increased to 25 °C. However, this trend was not significant. The results suggest that juvenile shortnose sturgeon show flexibility in their ability to adapt to various temperature environments and in their responses to exhaustive exercise.