Meeting Abstract
Fluctuations in ocean CO2 concentration and temperature can be especially dramatic in the intertidal zone. Thus, one may expect intertidal organisms to be less susceptible to ocean acidification (OA) and ocean warming (OW) compared to deeper organisms. While many intertidal organisms tolerate OA and OW in experiments, they usually experience changes in exoskeleton mineralization or increased oxidative stress. The intertidal mantis shrimp is a fierce predator that utilizes calcified, specialized appendages to deliver forceful punches to its prey. We examined oxidative stress in response to OA and OW as well as the exoskeleton structure, mineral content, and material properties of the merus segment of the predatory appendage and the carapace in the species, Neogonodactylus bredini. Mantis shrimp were maintained in three conditions for six months: ambient pH and temperature (7.9, 27°C), reduced pH and ambient temperature (7.6, 27°C), and reduced pH and increased temperature (7.6, 30°C). In contrast to previous studies on intertidal organisms, neither protein level indicators of oxidative stress nor exoskeleton calcium content showed significant responses to OA and OW. The merus, however, had significantly higher %Mg in reduced pH conditions, but there were no differences in stiffness and hardness of either the carapace or merus. These results indicate that, unlike other intertidal organisms, mantis shrimp tolerate an expanded range of pH and temperature without experiencing oxidative stress or large changes to the exoskeleton, thereby leaving the integrity of the predatory appendage intact. Given the power of the appendage, our findings imply that mantis shrimp may greatly impact intertidal food webs under future ocean conditions.
