Among mammals, birds, most reptiles and chondrichthians, only rhodopsins are present. Among agnat... more Among mammals, birds, most reptiles and chondrichthians, only rhodopsins are present. Among agnathans, osteichthians, amphibians and certain freshwater turtles there are species having only porphyropsins or only rhodopsins or, more interestingly, both pigments, either sequentially or together. This latter grouping represents the paired-pigment species. Associated with the presence of pairedpigments is the possibility that the proportions of rhodopsin and porphyropsin may change. Depending on the characteristics of each paired-pigment species, naturally occurring changes in visual pigment ratios are related to migrations in anadromous and catadromous teleosts and anadromous cyclostomes and to seasonal variation in several teleosts. In addition, the visual pigment composition of certain species of teleosts has been altered by the specific effects of light, temperature, diet and hormones. Of two possible mechanisms for altering spectral sensitivity, varying the proportion of rhodopsin and porphyropsin is far more common than utilizing a single chromophore and changing the opsin. In addition to the long established evidence that extractable rod pigment ratios may change during the life cycle or in response to specific exogenous factors, there is the more recent recognition from microspectrophotometry that cone pigment ratios may also change in concert. The effect of lighting conditions and temperature on the visual pigment composition of certain paired-pigment species is presented.
... JOSEFINE C. RAUCH Department of Zoology, University of Manitoba, Winnipeg, Man., Canada R3T 2... more ... JOSEFINE C. RAUCH Department of Zoology, University of Manitoba, Winnipeg, Man., Canada R3T 2N2 AND DAVID D. BEATTY Department of ... distribution have been reported for the monkey (Forsyth and Hoffbrand 1970), dog (Ericsson 1971), and rat (Rakusan and Blahitka ...
Lower water temperature (6 degrees C in comparison to 16 degrees C) favors a higher proportion of... more Lower water temperature (6 degrees C in comparison to 16 degrees C) favors a higher proportion of porphyropsin in the retina of rainbow trout (Salmo gairdneri), regardless of the light conditions (constant darkness or 12 hours of light and 12 of darkness). This response to temperature does not follow a Q10 relation, namely an increase in the rate of a reaction produced by raising the temperature 10 degrees C.
Among mammals, birds, most reptiles and chondrichthians, only rhodopsins are present. Among agnat... more Among mammals, birds, most reptiles and chondrichthians, only rhodopsins are present. Among agnathans, osteichthians, amphibians and certain freshwater turtles there are species having only porphyropsins or only rhodopsins or, more interestingly, both pigments, either sequentially or together. This latter grouping represents the paired-pigment species. Associated with the presence of pairedpigments is the possibility that the proportions of rhodopsin and porphyropsin may change. Depending on the characteristics of each paired-pigment species, naturally occurring changes in visual pigment ratios are related to migrations in anadromous and catadromous teleosts and anadromous cyclostomes and to seasonal variation in several teleosts. In addition, the visual pigment composition of certain species of teleosts has been altered by the specific effects of light, temperature, diet and hormones. Of two possible mechanisms for altering spectral sensitivity, varying the proportion of rhodopsin and porphyropsin is far more common than utilizing a single chromophore and changing the opsin. In addition to the long established evidence that extractable rod pigment ratios may change during the life cycle or in response to specific exogenous factors, there is the more recent recognition from microspectrophotometry that cone pigment ratios may also change in concert. The effect of lighting conditions and temperature on the visual pigment composition of certain paired-pigment species is presented.
... JOSEFINE C. RAUCH Department of Zoology, University of Manitoba, Winnipeg, Man., Canada R3T 2... more ... JOSEFINE C. RAUCH Department of Zoology, University of Manitoba, Winnipeg, Man., Canada R3T 2N2 AND DAVID D. BEATTY Department of ... distribution have been reported for the monkey (Forsyth and Hoffbrand 1970), dog (Ericsson 1971), and rat (Rakusan and Blahitka ...
Lower water temperature (6 degrees C in comparison to 16 degrees C) favors a higher proportion of... more Lower water temperature (6 degrees C in comparison to 16 degrees C) favors a higher proportion of porphyropsin in the retina of rainbow trout (Salmo gairdneri), regardless of the light conditions (constant darkness or 12 hours of light and 12 of darkness). This response to temperature does not follow a Q10 relation, namely an increase in the rate of a reaction produced by raising the temperature 10 degrees C.
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