Multimodalin situdatalogging quantifies inter-individual variation in thermal experience and persistent origin effects on gaping behavior among intertidal mussels (Mytilus californianus)

Abstract

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 () 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 the mussels' developmental environment. Mussels originating from a wave-protected, warm site gaped more widely, and 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.

Dynamic measurements of black oystercatcher (Haematopus bachmani) predation on mussels (Mytilus californianus)

“…The low cost and long life of the sensor and data logger package permit their usage in field settings where tide cycles and wave action might make other forms of long‐term observation such as human observers or cameras impractical. More generally, the types of sensor packages described here are providing new insights into bivalve feeding behavior (Riisgård, Lassen, & Kittner, ), growth (Ballesta‐Artero, Witbaard, Carroll, & van der Meer, ), responses to water quality (Sow, Durrieu, Briollais, Ciret, & Massabuau, ; Tran, Ciret, Ciutat, Durrieu, & Massabuau, ), and can allow researchers to better link the organism's interaction with the environment to its physiological status (Dowd & Somero, ; Gleason et al., ; Miller & Dowd, ).…”

“…The instrumentation and datalogging systems used for the mussels in this experiment are described in Miller and Dowd (). Briefly, we created an artificial mussel bed comprising 12 instrumented live mussels and several dozen additional live mussels (adult body size 40–70 mm shell length, harvested from the mid‐intertidal zone at HMS) on a 45 × 30 cm acrylic plastic plate (Figure ).…”

“…Here, we provide new insight into the dynamics of black oystercatchers feeding on M. californianus at a field site at Hopkins Marine Station (HMS hereafter) in Pacific Grove, CA (36.6217°N, 121.9043°W). During a field experiment designed to measure mussel behavior and physiology in M. californianus (Gleason et al., ; Miller & Dowd, ), we recorded incidental observations of oystercatcher predation events on three focal mussels. Using gape sensors and accelerometers attached to those mussels, we were able to record the accelerations and time course of oystercatcher predation events in the field.…”

“…Oystercatchers tend to switch prey species throughout the course of a falling or rising tide, turning their attention to Mytilus mussels as the mussel beds transition in or out of the water and mussels gape their valves, then moving to limpets or crabs when gaping mussels are not available. The proportions of mussels, limpets, and other prey in the diet of black oystercatchers vary among 2 | ME TH ODS The instrumentation and datalogging systems used for the mussels in this experiment are described in Miller and Dowd (2017). Briefly, we created an artificial mussel bed comprising 12 instrumented live mussels and several dozen additional live mussels (adult body size 40-70 mm shell length, harvested from the mid-intertidal zone at HMS) on a 45 × 30 cm acrylic plastic plate (Figure 1).…”

Recent Advances in Data Logging for Intertidal Ecology

“…Their results suggested no significant difference in animal temperature. Miller and Dowd (2017) also found that live M. californianus mussels in the intertidal that experienced high body temperatures during low tide (>25 • C) generally kept their shells closed more often than cooler mussels meaning this species likely does not utilize cooling through evaporation to control body temperature during hot conditions. Nicastro et al (2012) showed that individual mussels did not apparently cool as a result of gaping, but suggested that entire beds of mussels, acting in concert, could lead to overall cooling.…”