Visual pigment changes in rainbow trout in response to temperature.

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.