Presence of Rhodopsin and Porphyropsin in the Eyes of 164 Fishes, Representing Marine, Diadromous, Coastal and Freshwater Species—A Qualitative and Comparative Study^†

Abstract

There are two types of visual pigments in fish eyes; most marine fishes have rhodopsin, while most freshwater fishes have porphyropsin. The biochemical basis for this dichotomy is the nature of the chromophores, retinal (A1) and 3-dehydroretinal (A2), each of which is bound by an opsin. In order to study the regional distribution of these visual pigments, we performed a new survey of the visual pigment chromophores in the eyes of many species of fish. Fish eyes from 164 species were used to examine their chromophores by high-performance liquid chromatography--44 species of freshwater fish, 20 of peripheral freshwater fish (coastal species), 10 of diadromous fish and 90 of seawater fish (marine species) were studied. The eyes of freshwater fish, limb freshwater fish and diadromous fish had both A1 and A2 chromophores, whereas those of marine fish possessed only A1 chromophores. Our results are similar to those of previous studies; however, we made a new finding that fish which live in freshwater possessed A1 if living near the sea and A2 if living far from the sea if they possessed only one type of chromophore.

From crypsis to mimicry: changes in colour and the configuration of the visual system during ontogenetic habitat transitions in a coral reef fish

“…However, so far there are very few (if any) coral reef fishes that have been reported to contain A 2 chromophores within their photoreceptors (e.g. Toyama et al, 2008). Moreover, given that for both species the rod and SWS cones and in the dottyback also the 'normal' MWS and LWS cones are fitted by A 1 templates, it is unlikely that the broad spectra are due to chromophore mixtures.…”

Three cone opsin genes determine the properties of the visual spectra in the Japanese anchovy Engraulis japonicus (Engraulidae, Teleostei)

“…It is well known that the visual pigments of the cyprinid fish contain exclusively (goldfish) or predominantly (carp) porphyropsin based on a 3-dehydroretinal oxime (Bowmaker, 2008;Toyama et al, 2008), which is characterized by maximums of absorbance spectra that are shifted to longer wavelengths, as well as longer retention times, in comparison with the products of retinal (Groenendljk et al, 1980;Suzuki and Makino-Tasaka, 1983;Kondrashev, 2008). These data, in addition to the absence of a characteristic peak 2 on the anchovy chromatogram (Fig.3A), convincingly show that anchovy visual pigments are based only on retinal.…”

Rapid adaptive evolution of colour vision in the threespine stickleback radiation

“…Switches in chromophore use have been shown to occur in fishes over ontogeny [23] and between habitats via phenotypic plasticity [22]. Fishes in the ocean generally use A 1 chromophores, while freshwater fishes have a mixture of A 1 and A 2 chromophores (varying from completely A 1 to completely A 2 ) [22]. Complete use of A 2 is generally found in lakes whose waters are strongly stained with tannins (e.g.…”

“…Conjugation of an opsin to an A 1 chromophore (11-cis retinal) leads to a shorter wavelength of maximal absorption (l max ) than conjugation to an A 2 chromophore (3-dehydro 11-cis retinal) [21]. Switches in chromophore use have been shown to occur in fishes over ontogeny [23] and between habitats via phenotypic plasticity [22]. Fishes in the ocean generally use A 1 chromophores, while freshwater fishes have a mixture of A 1 and A 2 chromophores (varying from completely A 1 to completely A 2 ) [22].…”

“…We introduce a new metric to quantify the correlation between shift in spectral sensitivity and the transition between light environments. Shifts in spectral sensitivity can additionally be achieved by differential use of vitamin A-derived chromophores [21,22]. Conjugation of an opsin to an A 1 chromophore (11-cis retinal) leads to a shorter wavelength of maximal absorption (l max ) than conjugation to an A 2 chromophore (3-dehydro 11-cis retinal) [21].…”