As typical of intertidal invertebrates the asterinid seastar Parvulastra exigua experiences marked variation in environmental temperature and pH/pCO2 due to tidal exchange and diurnal patterns of photosynthesis and respiration. We characterized the temperature and pH/pCO2 conditions in the mid-intertidal, rocky-shore habitat of this species and used these data along with projections for the ocean over coming decades to define treatments in oxygen consumption experiments. The metabolic response of P.
The unusual rate and extent of environmental changes due to human activities may exceed the capacity of marine organisms to deal with this phenomenon. The identification of physiological systems that set the tolerance limits and their potential for phenotypic buffering in the most vulnerable ontogenetic stages become increasingly important to make large-scale projections. Here, we demonstrate that the differential sensitivity of non-calcifying Ambulacraria (echinoderms and hemichordates) larvae towards simulated ocean acidification is dictated by the physiology of their digestive systems.