Different markings in species of butterfly fish are used to aid in identification.
Therefore Butterflyfish mostly range from 12 to 22 cm in length. The largest species, lined butterflyfish and the saddle butterflyfish, grow to 30 cm.
Therefore the common name references the brightly colored and strikingly patterned bodies of many species, bearing shades of black, white, blue, red, orange, and yellow.
Although species are dull in color. Many have eyespots on their flanks and dark bands across their eyes, not unlike the patterns seen on butterfly wings.
Also the deep, laterally narrow bodies are easily noticed through the profusion of reef life. The conspicuous coloration of butterflyfish may be intended for interspecies communication.
Butterflyfish have uninterrupted dorsal fins with tail fins that may be rounded or truncated, but are never forked.