Meeting Abstract
Mantis shrimp are fierce predators that use specialized appendages to deliver fast and forceful punches to their prey. This predatory strike is powered by the energy storage capacity of the calcified exoskeleton. Given the substantial evidence that calcified structures of many marine organisms are affected by acidified ocean conditions, we studied the potential effects of ocean acidification (OA) and increased temperature on the mantis shrimp exoskeleton. Specifically, we examined the structure, mineral content, and material properties of the raptorial appendage and carapace exoskeleton. Individuals of the mantis shrimp species, Neogonodactylus bredini, were maintained in three water conditions: 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) for six months. At 3 months, we subsampled eight animals per treatment to test for short-term responses to OA. Exoskeleton structure and calcification were examined using scanning electron microscopy and energy-dispersive x-ray spectroscopy, and hardness and stiffness were examined using nanoindentation. Our results show that OA conditions do not significantly affect the mantis shrimp exoskeleton; cuticle structure, thickness, percent calcium, hardness, and stiffness of the appendage and carapace did not differ across treatments. These findings suggest that the integrity of the raptorial appendage, and thus the strike, is not compromised by moderate reductions in pH. The tropical, shallow waters that N. bredini inhabits exhibit seasonal and often daily fluctuations in pH and temperature. It is therefore likely that mantis shrimp, and possibly other reef flat crustaceans, are able to compensate for the OA conditions that could otherwise alter the exoskeleton and impact feeding mechanics.
