CARLETON, K L *; SPADY, T C; KOCHER, T D; University of New Hampshire; University of New Hampshire; University of New Hampshire: Visual sensitivities of cichlid fishes: Using DNA to see through the eyes of a fish

African Cichlid fishes are a textbook example of rapid vertebrate speciation, having evolved hundreds of species in the last million years. Cichlid visual communication, between females and brightly colored males, plays a key role in mate recognition and mate choice and may contribute to cichlids’ rapid speciation. To illuminate the cichlid view of the world, we have examined the visual sensitivities for several species from Lake Malawi and the tilapia, Oreochromis niloticus. Microspectrophotometry shows that cichlids have a wide range of visual pigment sensitivities, from ultraviolet through red wavelengths, with significant differences between species. By sequencing the opsin genes, which control visual sensitivities, and quantifying opsin gene expression, we have found that cichlids have nearly identical opsin gene sequences but different patterns of opsin gene expression. Therefore, differential gene expression is a mechanism whereby visual sensitivities can be shifted amongst closely related species. We have also studied the temporal changes in opsin gene expression through ontogeny and found that differences in adult gene expression are the result of changes in the timing of opsin gene expression through development. Visual sensitivities are therefore dynamically varying through early cichlid life stages.