OLSON, C.; GARNER, L.M.; BILOTTA, J.; MCELROY, D.*; Western Kentucky University; Western Kentucky University; Western Kentucky University; Western Kentucky University: Spectral sensitivity of ERG b- and d-waves in African cichlid fishes: comparisons with habitat, ecology and phylogeny

Previous studies indicate that African cichlid fish species express alternative combinations of five ancestral cone types, with peak sensitivities at 369, 447, 488, 533 and 570 nm (U-, S1-, S2-, L1- and L2- cones, respectively). Because many hypotheses relating to cichlid ecological divergence, sexual selection and speciation assume a primary role for coloration, it is essential to derive an understanding of the range and sensitivity of the cichlid visual system. Here we examine cone contributions to the photopic spectral sensitivity of electroretinogram (ERG) b- and d-wave responses in a number of closely-related cichlid species from Lake Malawi that differ in coloration, habitat and feeding ecology. Spectral sensitivity functions show significant differences in cone type contributions among species, as well as between b- and d-wave responses within species. Cone contribution results were consistent across all chromatic backgrounds tested. We use these data in a preliminary test for associations between spectral sensitivity and habitat use, trophic ecology and phylogentic relationships among species.