A plentiful nearshore reef species that subsists on thread-like algae is often observed in large groups while foraging. Juveniles of this species are often found in tidepools.
distinctive characters
This fish has a compressed body with a small mouth, a dorsal fin with 9 spines and 23 rays, an anal fin with 3 spines and 20 rays, and a pectoral fin with 2 spines and 13 rays. The first dorsal spine is short, about one third of the length of the second dorsal spine, and the first anal spine is also short. The pectoral fin is shorter than the head, and there is a lancet-like spine on the caudal peduncle which folds into a deep horizontal groove.