LAWRENCE, Karen A; STRANGE, Rex Meade; Southeast Missouri State University; Southeast Missouri State University: Evolution of Color Communication in Percid Fishes: A Role for Sensory Bias?

Color plays an important role in communicating male aggression and in courtship behavior in darters. However, it is unknown whether color vision played a role in the evolution of bright colors, or whether body colors evolved before color vision. We examined the phylogenetic distribution of retinal structure and color communication among twenty-four North American percid species and two European species in order to test the prediction that visual acuity evolved before body color. Bright body coloration is restricted to species of Etheostoma and is absent in Percina, Crystallaria, Zingel, Romanichthyes and the larger percids (Stizostedion and Perca). Species of Etheostoma and Percina have the lowest rates of neural summation (=highest acuity) regardless of body coloration among the percids. Summation rates are highest in Stizostedion and Perca and are typical of retinae specialized for low levels of ambient light. Zingel and Romanichthys exhibit retinal structures intermediate between darters and Stizostedion, despite their darter-like morphology. Phylogenetic distribution of retinal morphologies, habitat affinties, and color communication among percids suggests that color sensitivity evolved before the evolution of color communication.