The family Holocentridae has 2 subfamilies, Holocentrinae typically known as squirrelfish, and Myripristinae, typically known as soldierfish.
Members of these families are usually reddish with robust fin spines, and spines on the gill cover. The dorsal fin has 11 or 12 stout spines. Large, rough scales, with scale centres of the body often lighter (may be silvery white), possibly forming longitudinal bands. The tail fin is forked.
The preopercle spines (near the gill opening) of the members of the subfamily Holocentrinae (squirrelfish) are venomous, and can give painful wounds. Soldierfish do not have this spine, and can also be distinguished from squirrelfish by their more blunt snouts.
The squirrelfishes mainly feed on small fishes and invertebrates, while the soldierfishes typically feed on zooplankton. Members of these families are largely nocturnal (feed at night) and hence they have relatively large eyes. During the day, they typically remain hidden in crevices, caves, or under ledges.