Meeting Abstract
Since being introduced to the US, the invasive zebra mussel has rapidly spread throughout freshwater ecosystems. Zebra mussels cause extensive damage by harming native species and altering water quality, and they are extremely costly to remove from the hard surfaces to which they attach. Therefore, there is great interest in understanding their physiology in an attempt to limit, or at least predict, spread to new habitats. A previous experiment in our lab indicated energy imbalances are occurring during acute cold exposure. One possible explanation is that cold temperatures increased oxidative stress and impaired ATP production. While previous studies suggest reactive oxygen species increase in zebra mussels due to elevated metal concentration, high salinity, and pesticides, little is known about the links between temperature and oxidative stress in this species. Therefore, the specific aims of this project were to determine whether the invasive zebra mussel experiences oxidative stress during thermal fluctuations, and if so, which antioxidant is most active. We exposed zebra mussels to a cold stress in the lab by progressively decreasing water temperature from ambient river temperatures of 26°C to 10°C over three hours. Tissue was collected to determine superoxide dismutase activity, total antioxidant capacity, and the levels of TBARS. No significant changes in total antioxidant capacity or TBARS were seen, but superoxide dismutase activity increased after 12 hours at 10°C. We are currently using qPCR to expand these data to include the mRNA levels of superoxide dismutase, metallothionein, and catalase over time during this acute cold exposure.
