Cetacean visual pigments

Abstract

Visual pigments from marine cetaceans, as in other mammals, are homogeneous and based on the retinal-l chromophore, but show a wider range in absorption maxima. Maxima range from 497 to 486 nm and for one species to 481 nm, but with less certainty. This distribution correlates best with the dominant hue present in the habitat of each species. The diving habits of cetaceans provide behavioral contrasts to most marine fishes. The particular wavelength sensitivity of oceanic cetaceans perhaps represents a compromise intermediate to the dim blue radiance encountered at diving depths and the brighter blue-green radiance of surface waters.