Cardiovascular physiology of the edible crab Cancer pagurus under Ocean Warming and Acidification

Rising atmospheric CO2 levels have caused warming of the atmosphere and oceans and reduced the seawater pH. Thermal tolerance of marine ectotherms was shown to be reduced in high-CO2 waters, limiting chances for survival under the combined effects of warming and acidification. An enhanced temperature sensitivity in a high-CO2 ocean has been confirmed by reduced O2 levels in the body fluids of large marine crustacea. The haemolymph O2 level is a function of oxygen supply and demand and largely influenced by the activities of ventilatory and circulatory systems. The present work highlights the impact of combined CO2 and temperature effects on the ventilatory and cardiovascular performance of the edible crab Cancer pagurus. It adds to previous mechanistic studies on the general synergistic effects of both drivers, revealing limitations in ventilatory performance and cardiac work. The relevance of these results is underlined by the non-invasive measurements on truly resting animals.