Albino fish may need special consideration in the aquarium when it comes to lighting. Rupert Collins explains.
Amelanism or albinism, is a genetic condition whereby an individual appears white due to the lack of melanin pigments which colour the hair and skin, protecting it from excessive sun damage.
When all pigmentation is lacking, but eyes are the normal colour, this is alternatively termed leucism.
Like albinism, leucism can also be inherited but due to the entirely different developmental pathways to albinism, the eyes develop normally.
The iris and retina of the eye is red in albinos because the pigments usually conceal the underlying blood vessels.
It is this melanin which allows the human iris to act as a shutter, regulating the amount of light entering the eye as it opens and closes. Without these pigments, the eyes can become photosensitive, which is one of the many visual problems suffered by people with albinism.
Albinism effects all vertebrates in much the same way, so fishes are expected to have similar problems.
However, there are some critical differences – melanin is the only pigment system in mammals, and so albino humans will appear white, but fishes can also have a range of other pigment cells including xanthophores, erythrophores, iridophores, leucophores and cyanophores, which are unaffected by albinism.
For this reason, albino fishes can often look yellow, or have a yellow pattern due to the underlying xanthophores showing through.
Regarding vision, in lab experiments, albino Zebra danios were found to have significantly poorer vision under bright lighting conditions than their normally coloured counterparts. Under normal lighting vision did not differ, so it appears that the visual pigments not protected by melanin are temporarily bleached out under bright light.
So yes, if using multiple high output tubes or halide lighting in a planted tank, it may be better not to include albino fishes, just in case.
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