From the colourless state of the ventral surface of most fishes and of many other animals, we may reasonably suppose that the absence of colour in flat-fish on the side, whether it be the right or left, which is under-most, is due to the exclusion of light.
Ikusirik arrainik gehienen eta beste animalia askoren sabelaldea kolorga izaten dela, arrazoiz uste izan dezakegu arrainzapalek azpialdean, dela ezkerra dela eskuina, kolorerik ez izatea argirik ezaren ondorio dela.