Hawaiian Flagtail

Kuhlia xenura

The Hawaiian Flagtail, Kuhlia xenura, is a medium-sized fish endemic to Hawaii, found in various aquatic environments including fresh, brackish, and marine waters. It is characterized by a slightly concave dorsal profile of the head, a large eye, and a deeply forked caudal fin. The fish is primarily silver with a dark grey or dusky caudal fin featuring a thin black rear margin and often a pale submarginal band. Adult Hawaiian Flagtails can reach a standard length of up to 22.2 cm. This species is commonly found in tide pools, estuaries, and reefs over sand or rock, typically at depths ranging from 1 to 22 meters, but more often between 1 to 5 meters. They often form schools and are mainly nocturnal. In freshwater environments, their diet includes algae, insects, and planktonic crustaceans, while in brackish or marine settings, they consume a variety of crustaceans, insects, mollusc larvae, and polychaete worms. Spawning occurs throughout the year, peaking from December to June, and usually takes place at sea. Divers may encounter the Hawaiian Flagtail in schools during night dives, as they are more active at night. They are harmless to humans and have not been evaluated for conservation status by the IUCN.