C. ocellatus currently encompasses the Pacific and Indian Ocean populations and these are presently considered to be conspecific.

Juveniles are usually white with a thick orange band that surrounds the head, except snout and chin.

They have a black circular spot on their dorsal fin and a thick orange band on their rounded tail.

[2][3] Females of the initial phase have a dark purple to reddish brown head, finely spotted with black ventrally.

If for some reason this male were to leave or get separated, one of the dominant females of the group will take charge and change its gender and color.

This means that with climate change happening and the destruction of their habitat the bicolour parrotfish is less likely to adapt and more likely to die.

This information is important for aquariums to keep in mind, so they are able to treat their waters a certain manner before the parasite can get to the fish.

An experiment by Bellwood and Choat in 1990 showed that Cetoscarus ocellatus take 10% fewer bites of live coral in the Great Barrier reef compared to other parrot fishes.