Critical thermal maximum and minimum of juvenile shortnose sturgeon (Acipenser brevirostrum) acclimated to 12 and 18°C

Abstract

Thermal tolerance is crucial to understanding the biology of fishes and their responses to changes in temperatures, such as that produced by climate change. Shortnose sturgeon (Acipenser brevirostrum) is an endangered species (USA) and a species of special concern (Canada) that live on the eastern coast of North America. Although previous studies have focused on the acute critical thermal maximum (CT_max) of shortnose sturgeon, nothing is known with respect to their acute critical thermal minimum (CT_min) and the overall thermal tolerance of this species. This study examined the upper (CT_max) and lower (CT_min) thermal tolerance of shortnose sturgeon acclimated to 12 and 18°C. CT_max increased with increasing acclimation temperature; however, there was no significant relationship between acclimation temperature and CT_min. Taken together, the results of the present study show that shortnose sturgeon are well adapted to tolerate acute exposures to both cold and warm water environments.