Marine animals can have difficulties seeing well in the submarine environment, where light intensity, color range, and object contrast are all lower than in air. Nevertheless many marine animals have excellent vision, and one of the most complex eyes known is the compound eye of a crustacean called the mantis shrimp. This eye contains several classes of photoreceptors that include roughly 8 photopigments for color vision, another more than half dozen classes of polarization detectors, and a sensitive system of ultraviolet receptors. This work takes new technology of electro-optical devices into the field to explore the properties of the visual world underwater, and to use behavioral activity to assess visual perception. Using these animals as a model biological system, the work will clarify the evolution of visual adaptations for contrast enhancement and image analysis in difficult visual environments. Results will have broad impact on visual neuroscience, neuroethology, and comparative evolutionary studies; will have relevance to studies of ecological habitat and water quality; and will be important for suggesting new engineering approaches to machine vision.
