Nemo, alias Amphiprion ocellaris, belongs to the clownfish group, which includes about 30 species. Their colour pattern is characterised by a yellow, orange, brown or black colour with vertical white stripes composed of light-reflecting cells called iridophores.
In addition to other physical characteristics, clownfish species are distinguished by their number of vertical white stripes. Thus, some species have no stripes (Amphiprion ephippium), only one (Amphiprion frenatus) or just two (Amphiprion sebae). Amphiprion ocellaris, the famous Nemo, has three stripes. What can explain the difference in the number of bands between these species?