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

Abstract

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.

Does body size affect the response to exercise in shortnose sturgeon (Acipenser brevirostrum)?

“…However, exercise caused modifications in some of the secondary stress indicators (e.g., glucose, lactate and K + ). In this regard, the present results support our previous studies indicating that shortnose sturgeon have a muted physiological response to exhaustive exercise (Baker et al, ; Beyea et al, ; Kieffer et al, ; Zhang & Kieffer, ), relative to more active fish, such as salmonids (Kieffer et al, ).…”

“…It is now well known that shortnose sturgeon are slow, but consistent swimmers. They have lower aerobic swimming capacities (both endurance and burst swimming) (Deslauriers & Kieffer, ), and display a lower aerobic scope compared with salmonids and other teleosts (Zhang & Kieffer, ). Based on these life history traits and the fact that sturgeon display a small anaerobic capacity (generally indicated by the low amounts of lactate produced) (Kieffer et al, ; McLean et al, ), it is likely that there is a weak relationship between body size and the post‐exercise stress response.…”

Repeat UCrit and endurance swimming in juvenile shortnose sturgeon (Acipenser brevirostrum)

“…Post‐exercise plasma lactate and cortisol levels in juvenile shortnose sturgeon typically are low relative to teleosts (Baker et al ., ; Brown & Kieffer, ), and muscle energy reserves (PCr, glycogen) and lactate levels do not change substantially following exhaustive exercise (Kieffer et al ., ). The fact that the physiological response to exercise is muted and the time for post‐exercise recovery occurs quickly in juvenile shortnose sturgeon (Kieffer et al ., ; Zhang & Kieffer, ) may enhance their ability for repeated exercise. Unfortunately, assessment of the post‐exercise stress response was not completed for the current study.…”

“…Swimming to UCrit and/or at high endurance speeds likely involves the use of both aerobic and anaerobic metabolism (Brett, 1964;Kieffer, 2000;Zhang & Kieffer, 2017). In contrast to salmonids and other teleosts (Kieffer, 2000), juvenile shortnose sturgeon possess relatively low aerobic and anaerobic capacities (Baker et al, 2005;Kieffer et al, 2001;Zhang & Kieffer, 2017).…”

“…Swimming to UCrit and/or at high endurance speeds likely involves the use of both aerobic and anaerobic metabolism (Brett, 1964;Kieffer, 2000;Zhang & Kieffer, 2017). In contrast to salmonids and other teleosts (Kieffer, 2000), juvenile shortnose sturgeon possess relatively low aerobic and anaerobic capacities (Baker et al, 2005;Kieffer et al, 2001;Zhang & Kieffer, 2017). While the mechanism behind fatigue in fish still is not entirely clear, it has been suggested that a relationship exists between lactate accumulation, a commonly used indicator of anaerobic capacity, and fatigue during subsequent, repeated swimming events (Farrell et al, 1998;Jain & Farrell, 2003).…”