Hypoxia tolerance is unrelated to swimming metabolism of wild, juvenile striped bass (Morone saxatilis) [RESEARCH ARTICLE]

Krista Kraskura and Jay A. Nelson Juvenile striped bass residing in Chesapeake Bay are likely to encounter hypoxia that could affect their metabolism and performance. The ecological success of this economically valuable species may depend on their ability to tolerate hypoxia and perform fitness-dependent activities in hypoxic waters. We tested whether there is a link between hypoxia tolerance (HT) and oxygen consumption rate (MO2) of juvenile striped bass measured while swimming in normoxic and hypoxic water, and to identify the interindividual variation and repeatability of these measurements. HT (loss of equilibrium) of fish (N=18) was measured twice collectively, 11 weeks apart, between which MO2 was measured individually for each fish while swimming in low flow (10.2 cm s–1) and high flow (~67% of critical swimming speed, Ucrit) under normoxia and hypoxia. Both HT and MO2 varied substantially among individuals. HT increased across 11 weeks while the rank order of individual HT was significantly repeatable. Similarly, MO2 increased in fish swimming at high flow in a repeatable fashion, but only within a given level of oxygenation. MO2 was significantly lower when fish were swimming against high flow under hypoxia. There were no clear relationships between HT and MO2 while fish were swimming under any conditions. Only the magnitude of increase in HT over 11 weeks and an individual's MO2 under low flow were correl...
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research