Meeting Abstract
Since its introduction, the zebra mussel has caused widespread destruction by reproducing often, attaining high densities, and negatively impacting the ecosystem. While zebra mussel physiology has been examined for a range of abiotic factors, less is known about the impacts of biologically relevant habitat fluctuations, especially on a cellular level. In addition, there are discrepancies in the reported optimal conditions, which is likely the result of a large geographic range and localized adaptation. Therefore, this study aimed to investigate links between ambient conditions (water temperature, water quality, and food availability) and mussel performance (survival, growth, reproduction, and the levels of several cellular markers) by tracking mussels using field enclosures from September 2018 through July 2019. Survival was high, even when temperatures regularly exceeded 31°C, suggesting lethal limits are quite high for this population. Shell growth was highest when temperatures were moderately warm (June) and lowest when temperatures were both cold (November) and extremely hot (July). Tissue growth was highest in October, suggesting mussels gain mass in the cool autumn temperatures after spawning is complete. Significant tissue loss was detected in July, which likely reflects mass lost due to spawning as well as the negative impacts of thermal stress. These data indicate a temporal separation in soft tissue and shell growth. Despite high variation in habitat conditions over time, there were no significant differences in several stress markers examining oxidative stress and energy metabolism. Interestingly, there were significant differences in heat shock protein levels, with levels being highest in September and October when temperatures were moderate.
