Meeting Abstract

21.1  Saturday, Jan. 4 13:30  Behavioral and biophysical contributors to variation in body temperatures of intertidal mussels and their role in micro-scale physiological variation DOWD, W.W.*; SEARS, R.; CARLONE, M.; HOYT, J.; OTANICAR, T.; Loyola Marymount University; Loyola Marymount University; Loyola Marymount University; University of Tulsa; University of Tulsa wdowd@lmu.edu

Organisms on wave-exposed, rocky intertidal shores inhabit a spatially complex and temporally dynamic environment. Much effort has been devoted to studying patterns of physiological and/or genetic variation within and between such species, over latitudinal, vertical, seasonal or other relatively large scales. Our recent attention has been focused on the factors that might regulate micro-scale, intra-population variation in body temperature and physiology, which by some measures can rival or exceed mean differences over much larger scales. Solar irradiance is probably the dominant source of heat for many intertidal organisms. Here, we examined the potential roles of behavior (modification of body orientation and shell area exposed to solar irradiance) and shell surface reflectance characteristics in setting body temperatures of intertidal mussels of the genus Mytilus . We also quantified inter-individual variation in physiology – specifically, the biochemical capacities for ATP production and antioxidant defense – from within a single mussel bed both before and after eliminating solar heating by shading mussels at low tide. Our results implicate a complex suite of interacting factors that influence the body temperatures and physiological state of intertidal mussels. Supported by NSF and Loyola Marymount University.