Data from: Multimodal in situ datalogging quantifies inter-individual variation in thermal experience and persistent origin effects on gaping behavior among intertidal mussels (Mytilus californianus)

In complex habitats, environmental variation over small spatial scales can
equal or exceed larger-scale gradients. This small-scale variation may
allow motile organisms to mitigate stressful conditions by choosing benign
microhabitats, whereas sessile organisms may rely on other behaviors to
cope with environmental stresses in these variable environments. We
developed a monitoring system to track body temperature, valve gaping
behavior, and posture of individual mussels (Mytilus californianus) in
field conditions in the rocky intertidal zone. Neighboring mussels'
body temperatures varied by up to 14°C during low tides. Valve gaping
during low tide and postural adjustments, which could theoretically lower
body temperature, were not commonly observed. Rather, gaping behavior
followed a tidal rhythm at a warm, high intertidal site; this rhythm
shifted to a circadian period at a low intertidal site and for mussels
continuously submerged in a tidepool. However, individuals within a site
varied considerably in time spent gaping when submerged. This behavioral
variation could be attributed in part to persistent effects of
mussels' developmental environment. Mussels originating from a
wave-protected, warm site gaped more widely, and they remained open for
longer periods during high tide than mussels from a wave-exposed, cool
site. Variation in behavior was modulated further by recent wave heights
and body temperatures during the preceding low tide. These large ranges in
body temperatures and durations of valve closure events - which coincide
with anaerobic metabolism - support the conclusion that individuals
experience "homogeneous" aggregations such as mussel beds in
dramatically different fashion, ultimately contributing to physiological
variation among neighbors.