Butterflyfish actively protect their site from neighbors and, by the way, perfectly recognize representatives of their species in the general crowd. They fight furiously, and they do not touch other fish that are not their food rivals. At the same time, butterfly fish sometimes swim in small flocks, and in the breeding season they stay in pairs. These fish are active mainly during the day, and at night they hide in the secluded slits of the reef.
They feed on various small invertebrates, which are extracted in different ways. Most species simply look for small animals among corals, and often steal tidbits directly from the tentacles of coral polyps. Some species feed on the corals themselves, and the four-eyed bristle-toothed part-time functions as a clean-nurse and sometimes collects parasites from the skin of large fish.
External sex differences in fish-moths are weakly expressed or absent. Sexual maturity they usually reach at the end of the first year of life). Most species form married couples, others all the time keep flocks or unite into spawning congestions only during the breeding season.
In tropical waters, butterfly fishes reproduce year-round, however some species in some areas have seasonal spawning.
In species that do not have regular couples, the courtship process continues throughout the day, usually involving one female and several males, or a group of fish of different sex. By the end of the day, a pair is formed, and with the approach of twilight, spawning takes place. Males and females raise sexual products, quickly popping up to the surface of the water.