Causes and Consequences of Thermal Tolerance Limits in Rocky Intertidal Porcelain Crabs, Genus Petrolisthes

Abstract

Vertical zonation of intertidal organisms, from the shallow subtidal to the supralittoral zones, is a ubiquitous feature of temperate and tropical rocky shores. Organisms that live higher on the shore experience larger daily and seasonal fluctuations in microhabitat conditions, due to their greater exposure to terrestrial conditions during emersion. Comparative analyses of the adaptive linkage between physiological tolerance limits and vertical distribution are the most powerful when the study species are closely related and occur in discrete vertical zones throughout the intertidal range. Here, I summarize work on the physiological tolerance limits of rocky intertidal zone porcelain crab species of the genus Petrolisthes to emersion-related heat stress. In the eastern Pacific, Petrolisthes species live throughout temperate and tropical regions, and are found in discrete vertical intertidal zones in each region. Whole organism thermal tolerance limits of Petrolisthes species, and thermal limits of heart and nerve function reflect microhabitat conditions. Species living higher in the intertidal zone are more eurythermal than low-intertidal congeners, tropical species have the highest thermal limits, and the differences in thermal tolerance between low- and high-intertidal species is greatest for temperate crabs. Acclimation of thermal limits of high-intertidal species is restricted as compared to low-intertidal species. Thus, because thermal limits of high-intertidal species are near current habitat temperature maxima, global warming could most strongly impact intertidal species.

Effect of warming rate on the critical thermal maxima of crabs, shrimp and fish

“…The subtidal is a much more thermally stable environment, than the intertidal. Species inhabiting the intertidal have evolved specific adaptations that allow them to cope with environmental stress due to periodical exposure to terrestrial conditions (Stillman, 2002). A higher CTMax is believed to be a necessary evolutionary adaptation of intertidal organisms in contrast to the lower CTMax exhibited by subtidal organisms that do not suffer this level of environmental pressure (Mora and Ospina 2001;Madeira et al, 2012aMadeira et al, , 2012bMadeira et al, , 2014aMadeira et al, , 2014b.…”

Hábitat y historia de vida de Pachychelles laevidactylus (Crustacea, Anomura, Porcellanidae) en el intermareal rocoso de Mar del Plata, Argentina

“…Las especies que viven en el intermareal tienen adaptaciones específi cas que les permiten contrarrestar el estrés asociado al ambiente (Stillman, 2002), el cual pueden ser de carácter regular, como las fl uctuaciones de temperatura, salinidad y desecación, o estocásticos como la hidrodinámica turbulenta asociada a la rompiente y las tormentas marinas. Varios estudios han demostrado que cuanto mayores son los intervalos en que los sustratos están emergidos y sumergidos, más amplias son las variaciones térmicas; incluso, la tolerancia térmica puede ser un factor limitante más intenso que la desecación, especialmente cuando las temperaturas fl uctúan en un periodo de tiempo muy corto (Jensen & Armstrong, 1991;Stillman & Somero, 2000).…”

“…Varios estudios han demostrado que cuanto mayores son los intervalos en que los sustratos están emergidos y sumergidos, más amplias son las variaciones térmicas; incluso, la tolerancia térmica puede ser un factor limitante más intenso que la desecación, especialmente cuando las temperaturas fl uctúan en un periodo de tiempo muy corto (Jensen & Armstrong, 1991;Stillman & Somero, 2000). Además, la competencia, la predación y la preferencia por un tipo de sustrato también determinan el tipo de distribución (Stillman, 2002). En este sentido, muchos crustáceos viven asociados con especies sésiles (e.g.…”

Heartbeat sensors under pressure: a new method for assessing hyperbaric physiology

“…Measurements should therefore only be taken under a single behaviour, which most suitably is often resting. Although cardiac activity has been previously used to compare thermal tolerances in crustacean through Arrhenius break temperatures [38][39][40], a complimentary indicator of respiration is often desirable to correctly assess respiration and metabolic rates [37,41].…”