Double sash butterflyfish  (Chaetodon marleyi)

The double sash butterflyfish is classified as Least Concern (LC) on the IUCN Red List (1).

The double sash butterflyfish (Chaetodon marleyi) is superbly suited to its common name; it swims with flitting movements, evocative of the flight of a butterfly, and two prominent bars pattern each side of the body (2). These bars are golden-brown, contrasting sharply with the silvery-white scales covering the body, each bearing a small yellow spot in the centre. The body is round and narrow, with the mouth protruding in a sort of snout (2), and containing fine, elongate, inwardly-hooked teeth (2) (3). A dark, narrow band passes down through each eye and the fins may be yellowish, orange or translucent (2).

Found only in southern Africa, the double sash butterflyfish ranges from the Western Cape coast, South Africa, to the Bay of Maputo, Mozambique (4). It therefore occurs in both the Atlantic and Indian Oceans, the only butterfly fish to do so (2).

Although primarily a marine fish, which inhabits rocky or coral reefs, the double sash butterflyfish also enters estuaries, particularly juveniles which occurs in estuarine weedbeds. It occurs at depths between 1 and 120 metres (2).

This attractive fish feeds on a wide range of food as it flits around its reef habitat. Its broad diet includes small invertebrates, such as amphipods, crabs and marine worms, as well as seaweeds (2). The double sash butterflyfish often pecks this small prey from cracks in the reef (2), using its long, slightly hooked teeth (3). As well as providing food, the rocky or coral habitat also offers small crevices into which the fish can dart if threatened or alarmed (2).

Often seen in pairs, the double sash butterflyfish spawns between May and November, when females release many batches of eggs into the surrounding water. It is thought that the eggs hatch in late winter and spring (3). The double sash butterflyfish is a rather fast growing fish, with males reaching maturity at about two years old, when they measure around ten centimetres in length (3).

(1), although it may be negatively impacted by capture for the ornamental fish trade (3). It is said to do well in artificial tank environments, and is therefore valued by marine aquarists (2).

There are currently no conservation plans targeting the double sash butterflyfish, although it does occur in marine protected areas (1). Due to its popularity in aquariums, it has been suggested that measures should be implemented to prevent the over-exploitation of this species. These could include the ban of fishing during critical parts of the butterflyfish’s life cycle, as well as limits on the size of fish caught, to protect small juveniles and mature adults, and a limit on the number of individuals each person may catch (3).

View information on this species at the UNEP World Conservation Monitoring Centre.