Retinal Pigments of a Labrid Fish

Abstract

THE distribution of visual pigments in aquatic vertebrates has been assumed to follow this pattern¹: marine fishes possess rhodopsin (λ_max. 500 mµ), based on retinene₁, and freshwater fishes possess porphyropsin (λ_max. 522 mµ), based on retinene₂. Since the report by Wald¹ that labrid fishes have porphyropsin, the members of this family of marine teleosts have been regarded as exceptions to the general picture of visual pigment distribution. It should be made clear, however, that Wald did not study the visual pigment itself in the Atlantic species, Tautoga onitis and Tautogolabrus adspersus, which he examined, but based his conclusions on an analysis of the retinal vitamin A. Confirmation was reported by Kampa² for two unspecified corid (labrid) fishes in the Caribbean. She apparently studied the visual pigment, retinene and vitamin A, but only summarized her findings and has not published the full results. More recently, in a brief abstract³, Wald has stated again that Tautoga possesses porphyropsin.