The Wrought-iron Butterflyfish (Chaetodon daedalma) is a species of marine ray-finned fish belonging to the family Chaetodontidae. It is native to the western Pacific Ocean near central and southern Japan.

Distribution and Habitat

The Wrought-iron Butterflyfish is endemic to Japan where it is found on the main islands south of Sagami Bay, as well as the Ryukyu Islands, the Ogasawara Islands, and the Izu Islands. It is found in clear and outer waters at depths normally in excess of 10 meters. It prefers rocky reefs.

Physical Description

The Wrought-iron Butterflyfish is mainly metallic black in colour with yellow margins to the dorsal, anal and caudal fins. The body has markings resembling a cross-hatch pattern. The scales have pale yellow centres and broad black margins forming a lattice or netted pattern. The largely black colouration is very unusual for a species of butterflyfish which are normally much more colourful. This species attains a maximum total length of 15 cm (5.9 in).

Diet and Feeding

The Wrought-iron Butterflyfish grazes on algae and benthic invertebrates, including fanworms, hydroids, gastropods, barnacles, and tunicates. In captivity, it should be offered a varied diet including mysis shrimp, brine shrimp, spirulina, and marine algae.

Behavior and Reproduction

The Wrought-iron Butterflyfish is a sociable fish with adults normally found in schools numbering more than 10 individuals. They are also nomadic and the schools range over a wide area. Sometimes these fish congregate to graze in huge numbers, forming a tight formation referred to as a wrought-iron ball, which is thought to be a defensive strategy. It is an oviparous species with males and females forming pairs for breeding.

Aquarium Care

The Wrought-iron Butterflyfish is uncommon in the aquarium trade outside Japan as it has a restricted distribution and prefers cooler conditions than related species. When exported it commands a high price. It requires a tank of at least 55 gallons with stable water conditions and cooler temperatures. It is generally peaceful.

Conservation Status

Classified as Least Concern by the IUCN Red List.