Adult males, also known as terminal stage, are shades of blue or green, and have pink lines radiating from their eyes.

Adult females, also known as the initial phase, are mottled brown and their eyes bulge out slightly.

[5][6] Calotomus carolinus has a wide Indo-Pacific distribution from the coast of East Africa, although not in the Red Sea where it is replaced by Calotomus viridescens, through the Indian Ocean to the eastern Pacific Ocean around the Revillagigedo and the Galapagos Islands.

[2] Calotomus carolinus can typically be found as a single fish or in small groups, in shallow reefs or lagoons.

Within the wider habitat this species can be found in areas of coral, rubble, seagrass and algae.