CHEROSKE, AG; CRONIN, TW; University of Maryland, Baltimore County; University of Maryland, Baltimore County: �All in favor, say eye�: Adaptive color and postural signaling by stomatopod crustaceans in different light environments.

Stomatopods (mantis shrimp) are aggressive benthic marine predators with color vision plausibly better than any animal. Because many stomatopods use ritualized displays of conspicuously colored spots, relevant organismal information may be conveyed using color. Many stomatopods occupy wide depth ranges (<1 m � 30 m) where the corresponding variation in light environment can influence color perception. To test the potential behavioral effects of differing ambient light on signaling, stomatopods (Gonodactylus smithii) interacted with models and conspecifics under �shallow� white and �deep� blue light in aquaria. Model stomatopods varied in �meral spots� and body stances that are used during displays. Meral spot variants included changes in spectral, intensity and spatial properties. After trials, spectral measurements from various body spots were conducted on animals to assess potential sexual differences. During intra- and intersexual trials, stomatopods used color signals more in their native light (shallow) but used significantly more signals of other modalities in deep light. Females were more aggressive and initiated more combative acts regardless of light. Results from model assays were complex but may be explained partially by spectral measurements. G. smithii is sexually dimorphic in overall body color and also on the dactyl enlargement but there are no sexual differences in meral spot color. Findings suggest that stomatopods use a variety of signals during interactions to communicate. Changes in light environment can cause plastic behavioral responses that potentially maximize signal transfer.