Found among coral heads and rocks of subtidal lagoon and seaward reefs (Ref. 4919, 5503). Common on coastal reefs at various depths. Mimic filefish, males are territorial and are often seen fighting (Ref. 48637). Feed mainly on filamentous green and red algae, tunicates, and on smaller amounts of corals, bryozoans, polychaetes, echinoderms, mollusks, and brown and coralline red algae. Form shoals (10-100 or more) often with the filefish, Paraluteres prionurus
(about 5% of shoal) mimicking C. valentini
to protect it from predators (Ref. 4919, 5503). Territorial and haremic; males spawn with a different female each day (Ref. 9710). One or more territories are occupied and defended each by a female where a single large male stands guard (Ref. 55082). All sexually mature females are territorial females (Ref. 55082). Demersal spawner (Ref. 35298).