Estimated absorbance spectra of the visual pigments of the North Atlantic right whale (Eubalaena glacialis)

To assess the spectral sensitivities of the retinal visual pigments from the North Atlantic right whale (Eubalaena glacialis), we have cloned and sequenced two exons from the rod opsin gene and two exons from the middle-wavelength sensitive (MWS) cone opsin gene in order to determine the amino acids at positions known to be key regulators of the spectral location of the absorbance maximum (lambda(max)). Based on previous mutagenesis models we estimate that the right whale possesses a rod visual pigment with a lambda(max) of 499 nm and a MWS cone visual pigment with a lambda(max) of 524 nm. Although the MWS cone visual pigment from the right whale is blue-shifted in its spectral sensitivity like those from odontocetes, the spectral sensitivity of the right whale rod visual pigment is similar to those from terrestrial mammals.