81.6 Friday, Jan. 6 Why stomatopods are striking DEVRIES, M. S.*; CHRISTY, J. H.; Univ. of California, Berkeley; Smithsonian Tropical Research Institute email@example.com
Some species of stomatopod crustaceans produce extremely fast and powerful strikes with highly specialized appendages. These strikes are thought to be used both for crushing hard-shelled prey and for fighting with other stomatopods. Yet, we know little about the relative use of the striking behavior for predation and aggression. To begin to untangle how strikes are used, we first examined strikes in the context of feeing. Using stable isotopes and behavioral experimentation, we determined the diet of the stomatopod, Neogonodactylus bredini, a common predator on Caribbean coral reefs. Although we had expected individuals to consume hard-shelled prey items exclusively, we found that 17% of the diet consisted of soft-bodied prey. Observations of feeding events on live prey showed that N. bredini used multiple strikes to break apart hard prey but often only one or a few strikes to stun or kill soft-bodied prey. Powerful strikes may be favored if food items are rarely found and stomatopods must be prepared to break hard prey when they are encountered. We observed stomatopods in the field and measured prey abundance. Although, prey items (crabs, hermit crabs, snails, worms) were abundant where stomatopods were active, in 100 hours of observations no direct prey capture events were documented. However, we observed 20 aggressive interactions in which the stomatopods actively struck at each other, suggesting that during their daily activities, strikes are important for dealing with intraspecific aggressive interactions. Overall, the dual-functionality of the stomatopod strike appears to widen diet breadth while also allowing stomatopods to be aggressive towards competitors in a diverse coral reef environment.