Thermal stress decreases developmental stability in marine mussels.
Faced with rising environmental temperatures, there is growing evidence that species are exhibiting shifts in ecological distribution, physiological performance, behavioral strategy and developmental rate. However, the efficacy of these varied responses is often rooted in an organism’s ability to fulfill precise developmental patterns. Links between environmental conditions and the precision with which organisms are able to fulfill their developmentally programmed phenotype remains an important, and largely unanswered question. Results from our lab and field experiments suggest that developmental instability, as assessed by the fluctuating asymmetry of right versus left valves in intertidal mussel shells, increases under elevated aerial temperatures. These results imply that the precision of developmental processes can be perturbed by environmental conditions and raise developmental instability as a potential impact of future climate change alongside shifts in physiology, behavior and biogeographic distribution.
Future work will explore the functional consequences of shell asymmetry in marine mussels. The degree to which developmental instability may or may not affect the ecology of mussels in the field or in aquaculture remains an interesting and unanswered question.
Ecological consequences of changing patterns of temperature variation in bivalves
Faced with rising temperatures, there is growing evidence that marine organisms are exhibiting shifts in growth, distribution, abundance and physiological performance. However, changes in climate are also predicted to influence the frequency and duration of extreme thermal events. Not surprisingly, the biological impacts of temperature fluctuation remain less well understood compared with changes in mean temperature. To address this issue, we are examining patterns of respiration, feeding, growth, and gene expression in marine mussels, Mytilus spp., under stable water temperatures and fluctuating thermal regimes.
With the help of undergraduate research assistants, I am currently running experiments comparing the effects of stable versus fluctuating temperatures on mussel physiology, behavior and growth.
Gene expression work
Sunrise at Rhode Island field site.
Fig. 1. Phenotpic variation. Plasticity, canalization and instability
Fig. 2. Temperature variation in barnacle temperatures.
