Visual Opsin Diversity in Sharks and Rays.

摘要: The diversity of color vision systems found in extant vertebrates suggests that different evolutionary selection pressures have driven specializations photoreceptor complement and visual pigment spectral tuning appropriate for an animal's behavior, habitat, life history. Aquatic particular show high variability chromatic become important models understanding the role prey detection, predator avoidance, social interactions. In this study, we examined capacity elasmobranch fishes, a group received relatively little attention to date. We used microspectrophotometry measure absorbance pigments outer segments individual photoreceptors from several ray shark species, sequenced opsin mRNAs obtained retinas same as well additional species. reveal phylogenetically widespread occurrence dichromatic rays based on two cone opsins, RH2 LWS. also confirm all species studied date appear be monochromats but report single may either LWS or class. From this, infer monochromacy sharks has evolved independently multiple occasions. Together with earlier discoveries secondarily aquatic marine mammals, cone-based use large predators, such sharks, pinnipeds, cetaceans.