Critical thermal maximum (CTmax) and hematology of shortnose sturgeons (Acipenser brevirostrum) acclimated to three temperatures

Canadian Journal of Zoology, Volume 92, Issue 3, Page 215-221, March 2014. Quantifying a species thermal tolerance is critical to assessing biological impacts of anticipated increases in temperature (e.g., climate change). Although many studies have documented the critical thermal maximum (CTmax) of fish, there is a paucity of research on thermal biology of sturgeon. The shortnose sturgeon (Acipenser brevirostrum LeSueur, 1818) is a threatened species that exists along the eastern coast of North America. They can be exposed to temperatures ranging from freezing to above 25 °C. Using a heating rate of 6 °C/h, CTmax and the associated hematological responses of shortnose sturgeon acclimated to 10, 15, and 20 °C were determined. There was a significant positive relationship between CTmax and body mass, and CTmax increased significantly with increases in acclimation temperature (Ta). In general, hematology of thermally stressed fish was modified relative to control (nonstressed) fish. Hematocrit, plasma lactate, and plasma Na+ and Cl– of fish were all significantly influenced by thermal stress and Ta. Glucose and K+ were only significantly influenced by thermal stress. Future studies should address the importance of other stressors, such as salinity and toxicants, on thermal relationships of sturgeon.
Source: Canadian Journal of Zoology - Category: Zoology Tags: article Source Type: research