Thermally mediated body temperature, water content and aggregation behaviour in the intertidal gastropodNerita atramentosa

Abstract

Intertidal organisms are vulnerable to global warming as they already live at, or near to, the upper limit of their thermal tolerance window. The behaviour of ectotherms could, however, dampen their limited physiological abilities to respond to climate change (e.g. drier and warmer environmental conditions) which could substantially increase their survival rates. The behaviour of ectotherms is still mostly overlooked in climate change studies. Here, we investigate the potential of aggregation behaviour to compensate for climate change in an intertidal gastropod species (Nerita atramentosa) in South Australia. We used thermal imaging to investigate (1) the heterogeneity in individual snail water content and body temperature and surrounding substratum temperature on two topographically different habitats (i.e. rock platform and boulders) separated by 250 m at both day‐ and night‐times, (2) the potential relationship between environment temperature (air and substratum) and snail water content and body temperature, and (3) the potential buffering effect of aggregation behaviour on snail water content and body temperature. Both substratum and snail temperature were more heterogeneous at small spatial scales (a few centimetres to a few metres) than between habitats. This reinforces the evidence that mobile intertidal ectotherms could survive locally under warmer conditions if they can locate and move behaviourally in local thermal refuges. N. atramentosa behaviour, water content and body temperature during emersion seem to be related to the thermal stability and local conditions of the habitat occupied. Aggregation behaviour reduces both desiccation and heat stresses but only on the boulder field. Further investigations are required to identify the different behavioural strategies used by ectothermic species to adapt to heat and dehydrating conditions at the habitat level. Ultimately, this information constitutes a fundamental prerequisite to implement conservation management plans for ectothermic species identified as vulnerable in the warming climate.

Using ecophysiological traits to predict climatic and activity niches: lethal temperature and water loss inMediterranean ants

“…Lethal temperature may also predict spatio‐temporal variation in species activity at a local scale (Miller et al ., ; Wittman et al ., ; Chapperon et al ., ). Indeed, some studies have found that thermal niches are the most important predictors of coexistence of ant species in local communities (Retana & Cerdá, ; Lessard et al ., ; Wittman et al ., ).…”

“…Thus, to evaluate the impact of regional climatic change on species and communities we must first understand the physiological responses of organisms to the environment and, more specifically, to warming. For instance, it has been stated that species thermal tolerance maxima predict species responses to environmental changes at the local scale (Cerdá et al ., ; Miller et al ., ; Wittman et al ., ; Diamond et al ., ; Chapperon et al ., ). Moreover, other physiological traits, for example desiccation resistance and metabolic rate, may also help predict a species' success under different conditions (Lighton & Bartholomew, ; Hood & Tschinkel, ; Chown et al ., ).…”

Coping with Daily Thermal Variability: Behavioural Performance of an Ectotherm Model in a Warming World

“…For instance, in hypervariable environments as the intertidal [60], [62], the gastropod Nerita atramentosa behaviorally avoid the high temperatures through selection of thermal refuges as well as through huddling. Thus, as terrestrial isopods (this study), the behavior of marine gastropod during emersion seems to be related by local thermal stability or variability of the environment [63]. Theoretically, in variable habitats it is beneficial for ectotherms to select temperatures below thermal physiological optimum [64].…”

Morphometric analysis of the shell of the intertidal gastropod Echinolittorina lineolata (d'Orbigny, 1840) at different latitudes along the Brazilian coast

“…The latitude, in association with other factors, can directly influence the size of the gastropods (Linse et al, 2006). These factors may include body temperature (Chapperon et al, 2013;Seuront & Ng, 2016), food availability (Apolinário et al, 1999), density-dependent intraspecific competition (Magalhães, 1998) and phenotypic plasticity (Hollander et al, 2006). According to Bernardino et al (2015), the extreme conditions of El Niño, combined with long-term global warming, can lead to thermal stress on benthic assemblages found in the mid-latitudes of the tropics, and short-term osmotic stress of those organisms found in the estuaries of south-eastern Brazil.…”