Meeting Abstract
Crabs in the family Majoidae camouflage by decorating their exoskeletons with organisms and debris from their environment. This form of camouflage, involving both the act of decorating and carrying of these decorations, is thought to be energetically costly, and possibly even more so under stressful environmental conditions. Previous research has shown that many marine calcifiers experience stress and/or impacts on calcification under experimental ocean acidification conditions, which ultimately affects energy allocation. We therefore hypothesized that energy will be diverted towards regulatory processes, such as calcification, in decorator crabs under reduced pH conditions, thereby negatively affecting decorating behavior. Dwarf teardrop crabs, Pelia tumida, were exposed to ambient (8.1) and low (7.7) pH conditions for five weeks. Half of the animals in each treatment were given live Halichondria panicea sponge to decorate with, whereas the remaining animals were not allowed to decorate. Electron dispersive x-ray spectroscopy (EDX) showed that calcium and magnesium concentrations (wt%) of the exoskeleton did not change under reduced pH conditions. Neither mass nor percent coverage of sponge differed between decorated treatments, indicating no effect of reduced pH on decorating behavior. The ability of these decorator crabs to maintain normal calcification and decorating behavior under reduced pH conditions may aid in their camouflage and survival in the future oceans. This study adds to the growing number of marine species that appear to be resilient to ocean acidification.
