Myth
Fish are color blind.
done
This statement is pretty meaningless. Fish are even more varied than mammals. It would be like saying ‘Mammals are color blind’. I’m a mammal, but I’m not color blind. Some mammals cannot see color. Primates, i.e. apes, monkeys, lemurs, humans, etc., can generally see color. Other mammals may or may not be colorblind, depending on the type and the individual. Rats are believed to have bicolor vision, seeing in two of the primary colors that humans can see.
Except not all humans can see all three colors. In fact, one man in five has red-green color blindness, although only one woman in twenty-five has this form of color blindness.
Similarly, fish vary. Some of the experiments done to see if Goldfish can remember involved seeing if Goldfish could associate different colored objects with food. They can. This suggests that Goldfish can see color.
It is reasonable to expect that individual fish within a species will vary in their color vision, just as humans do.
Another question we can ask ourselves is: if fish are color blind, why are so many fish colourful? This goes further, because many types of fish become more colorful in the breeding season. To me this suggests that these fish can see each other’s colours.
There is also evidence that color is one of the things fish use to recognize their own species, and color is also used to allow them to come together in schools.
