The orangeback angelfish (''Centropyge acanthops''), also known as the flameback angelfish, African pygmy angelfish and in South Africa as the Jumping Bean or Bean, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of ray-finned fish, a marine angelfish belonging to the family Pomacanthidae. It is found in the western Indian Ocean.

Description

The orangeback angelfish has the head, upper flanks, the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

and the

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

are golden yellow in colour. The lower flanks and the

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

are black with many dense purple spots. Their eyes are ringed with blue. This species attains a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

of .

Distribution

The orangeback angelfish is found in the western Indian Ocean. It occurs along the East African coast from Somalia south to

East London East London is the part of London, England, east of the ancient City of London and north of the River Thames as it begins to widen. East London developed as London Docklands, London's docklands and the primary industrial centre. The expansion of ...

in the

Eastern Cape Province The Eastern Cape ( ; ) is one of the nine provinces of South Africa. Its capital is Bhisho, and its largest city is Gqeberha (Port Elizabeth). Due to its climate and nineteenth-century towns, it is a common location for tourists. It is also kno ...

, as well as Madagascar, Seychelles, Comoros, the

Chagos Islands The Chagos Archipelago (, ) or Chagos Islands (formerly , and later the Oil Islands) is a group of seven atolls comprising more than 60 islands in the Indian Ocean about south of the Maldives archipelago. This chain of islands is the southernmo ...

and the

Mascarene Islands The Mascarene Islands (, ) or Mascarenes or Mascarenhas Archipelago is a group of islands in the Indian Ocean east of Madagascar consisting of islands belonging to the Republic of Mauritius as well as the French department of Réunion. Their na ...

. In Asia it has been recorded from the

Gulf of Aden The Gulf of Aden (; ) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channel, the Socotra Archipelago, Puntland in Somalia and Somaliland to the south. ...

and the

Arabian Sea The Arabian Sea () is a region of sea in the northern Indian Ocean, bounded on the west by the Arabian Peninsula, Gulf of Aden and Guardafui Channel, on the northwest by Gulf of Oman and Iran, on the north by Pakistan, on the east by India, and ...

off Yemen, including

Socotra Socotra, locally known as Saqatri, is a Yemeni island in the Indian Ocean. Situated between the Guardafui Channel and the Arabian Sea, it lies near major shipping routes. Socotra is the largest of the six islands in the Socotra archipelago as ...

, and Oman as well as the Maldives. It has also been recorded from the Australian territory of the

Cocos (Keeling) Islands The Cocos (Keeling) Islands (), officially the Territory of Cocos (Keeling) Islands (; ), are an Australian external territory in the Indian Ocean, comprising a small archipelago approximately midway between Australia and Sri Lanka and rel ...

Habitat and biology

The orangeback angelfish is found at depths between , usually near coral and frequently in area of coral rubble where it likes to hide among the rubble. It prefers areas with dense algal growth and it grazes on algae and small invertebrates. It is a social species which is typically encountered in groups of up to 10 fishes. They are protogynous hermaphrodites in which the most dominant female in a group becomes male, this can be reversed if the dominance is lost. This species spawns at dusk, the male bites the females on the abdomen to stimulate her to lay eggs he fertilises and the eggs are then left to drift on the current.

Systematics

The orangeback angelfish was first formally described as ''Holacanthus acanthops'' in 1922 by the English

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

John Roxborough Norman John Roxborough Norman (1898, Wandsworth, London – 26 May 1944, Berkhamsted, Hertfordshire) was an English ichthyologist. He started as a clerk in a bank. His lifetime affliction with rheumatic fever began during his military service during the ...

(1898-1944) with the type locality given as

Durban Durban ( ; , from meaning "bay, lagoon") is the third-most populous city in South Africa, after Johannesburg and Cape Town, and the largest city in the Provinces of South Africa, province of KwaZulu-Natal. Situated on the east coast of South ...

. In some classifications it is placed in the subgenus ''Xiphipops''. The specific name ''acanthops'' is a compound of ''acanthus'' meaning “spine” and ''ops'' meaning “eye” and is a reference to the rearward directed spine under the eye.

Utilisation

The orangeback angelfish is common and popular in the aquarium trade. It has been bred in captivity.

References

External links

Centropyge.net info page
{{Taxonbar, from=Q3643498 orangeback angelfish Fish of Madagascar Fauna of the Maldives Fauna of the Mascarene Islands Fish of the Comoros Fish of Seychelles Marine fish of East Africa Fish of the Indian Ocean Taxa named by John Roxborough Norman orangeback angelfish