Meeting Abstract
90.1 Monday, Jan. 6 13:30 Sublethal temperature tolerance of the invasive zebra mussel, Dreissena polymorpha: Linking growth to cellular indicators of temperature stress JOST, JA*; KESHWANI, S; SOLTIS, E; MOYER, M; VEZINAW, C; Bradley University jjost@bradley.edu
Temperature stress has been examined in the context of climate change and there is a interest in measuring thermal stress for invertebrates. While climate models predict that invertebrates will be one of the most affected groups as temperatures increase, there are missing links in our knowledge of the physiology. For example, lethal temperatures have been examined for many species, but the organismal and cellular effects of high, but sublethal, temperatures are poorly understood. As an invasive species, the zebra mussel, Dreissena polymorpha, can serve as a model invertebrate species. Zebra mussels are capable of biofouling hard substrates, causing severe damage, and therefore, studies investigating zebra mussel physiology may offer insight into the survival and spread of this species. Previous work has examined the lethal limits for zebra mussels, but few have investigated the cellular mechanisms of temperature tolerance or the link between temperature and non-lethal effects such as reduced growth. This study examined the relationship between high temperature stress, AMP-activated protein kinase activity (an indicator of cellular energy), heat shock protein (HSP) levels and growth for the zebra mussel. Animals were maintained at one of three water temperatures (10, 20 or 30°C) for either 12 weeks (winter) or 8 weeks (summer). Data show that prolonged exposure to 30°C results in high mortality, decreased growth (both tissue and shell mass) and an extensive HSP response while AMPK activity does not appear to be a strong indicator of long term stress. In addition, preliminary results suggest that summer collected mussels are less prone to high temperature stress than winter collected animals indicating a seasonal thermal acclimation mechanism is present.
