About Chelmon marginalis Richardson, 1842
Chelmon marginalis has a silvery white body with two slender orange bars across its head and the front portion of its body. It also has a wide yellowish or yellowish-orange band positioned close to the caudal peduncle. Adult individuals of this species do not have a false eyespot, or ocellus, on the dorsal fin. Juveniles have an additional bar near the tail and an ocellus on the dorsal fin; these markings fade and eventually disappear completely as the fish matures. The dorsal fin of Chelmon marginalis has between 9 and 10 spines and 29 to 33 soft rays, while the anal fin has 3 spines and 21 to 22 soft rays. This species reaches a maximum total length of 18 centimetres, which equals 7.1 inches. Chelmon marginalis is endemic to Australia. Its range extends from the Houtman Abrolhos in Western Australia, along the coasts of northern Australia, to the northern Great Barrier Reef and the reefs of the Coral Sea off Queensland. This species occurs mostly on coastal coral reefs and rocky reefs. It can also be found on outer reef slopes, drop-offs, and around nearshore islands. It is a carnivorous fish that preys on benthic invertebrates including crabs, shrimps, and polychaetes. It is typically a solitary species, and forms breeding pairs. This species reproduces via oviparous breeding.
