The visual ecology of a color polymorphic reef fish: the role of aggressive mimicry

Since all forms of mimicry are based on perceptual deception, the sensory ecology of the intended receiver is of paramount importance to test the necessary precondition for mimicry to occur, i.e. model-mimic misidentification, and to gain insight in the origin and evolutionary trajectory of the signals. Here we test the potential for aggressive mimicry by a group of coral reef fishes, the color polymorphic hamlets, from the point of view of their most common prey, small epibenthic gobies and mysid shrimp. We build visual models based on the visual pigments and spatial resolution of the prey, the underwater light spectrum and color reflectances of putative models and their hamlet mimics. Our results are consistent with one mimic-model relationship between the butter hamlet and its model the butterflyfish but do not support a second proposed mimic-model pair between the black hamlet and the dusky damselfish . We discuss our results in the context of color morphs divergence in the species radiation and suggest that aggressive mimicry in might have originated in the context of protective (Batesian) mimicry by the hamlet from its fish predators.