Behavioral repertoire of high‐shore littorinid snails reveals novel adaptations to an extreme environment. Issue 12 (2nd May 2021)

• Record Type: Journal Article
• Authors: Ng, Terence P. T.; Lau, Sarah L. Y.; Davies, Mark S.; Stafford, Richard; Seuront, Laurent; Hutchinson, Neil; Hui, Tommy T. Y.; Williams, Gray A.
• Is Part Of: Ecology and evolution. Volume 11:Issue 12(2021)
• Page Start: 7114
• Page End: 7124
• Publication Date: 2021-05-02
• Subjects: activity budget -- Echinolittorina malaccana -- Echinolittorina radiata -- intertidal -- snail -- thermal stress -- thermoregulation -- trail following; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.7578
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Species that inhabit high‐shore environments on rocky shores survive prolonged periods of emersion and thermal stress. Using two Hong Kong high‐shore littorinids ( Echinolittorina malaccana and E . radiata ) as models, we examined their behavioral repertoire to survive these variable and extreme conditions. Environmental temperatures ranged from 4°C in the cool season to 55.5°C in the hot season, with strong seasonal and daily fluctuations. In the hot season, both species allocated >35% of their activity budgets to stress‐mitigating thermoregulatory behaviors (e.g. standing, towering) and relatively small proportions to foraging (<20%) and reproduction (<10%). In the assumedly benign cool season, greater proportions (>70%) of activity budgets were allocated to stress mitigation behaviors (crevice occupation, aggregation formation). Both species exhibited multifunctional behaviors that optimized time use during their tidally‐constrained activity window in the hot season. Females mated while foraging when awash by the rising tide, and some males crawled on top of females prior to ceasing movement to form 'towers', which have both thermoregulatory benefits and reduce searching time for mates during subsequent activity. The function of such behaviors varies in a state‐dependent manner, for example, the function of trail following changes over an activity cycle from mate searching on rising tides, to stress mitigation on falling tides (aiding aggregation formation), and to both functions through tower formation just before movement stops. Many of these behavioral responses are, therefore, multifunctional and can vary according to local conditions, allowing snails in this family to successfully colonize the extreme high‐shore environment. Abstract : High shore littorinids experience strong variations in temperature on seasonal and daily bases. Within these regimes, they show multifunctional behaviours that have thermoregulatory benefits. The function of such behaviours varies in a state‐dependent manner.