TSENG, Jack; PATEK, Sheila; University of California, Berkeley; University of California, Berkeley: Looking for trouble: strike response to conspecific body colors in the peacock mantis shrimp

Peacock mantis shrimp (Odontodactylus scyllarus) are spectacularly colored, with particular body regions also reflecting polarized light. In addition, they have potent raptorial appendages, with which they produce extremely fast and powerful strikes. These raptorial strikes are used for predator defense, prey capture, and during agonistic interactions with conspecifics. Visual signals play an important role in conspecific interactions and previous research has shown that the peacock mantis shrimp can perceive color. Thus, the bright body coloration, coupled with highly aggressive behavior, make O. scyllarus an excellent system for studying the influence of particular conspecific body colors on agonistic responses. We conducted a series of experiments to test which body colors, with and without polarization, were most likely to elicit a raptorial strike response in O. scyllarus. We constructed polarized and unpolarized color plates with wavelengths closely matching the various body colors of a typical O. scyllarus. Each color plate was mounted on a piezoelectronic force sensor. Animals were presented with a random sequence of colors and polarizations and their strike response was documented. We analyzed both the discrete response (presence or absence of strike) and graded response (amount of force) to the presentation of the color stimulus. Results suggest that individuals vary in their response to particular colors, and that juveniles and adults respond differently. Results also show that animals are more likely to strike color plates representing principal body colors than colors found only on localized areas of the body. Overall, individuals may have a higher response to polarized colors.