''Chaetodon triangulum'', the triangle butterflyfish or herringbone butterflyfish, is a species of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

, a

butterflyfish The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. The approximately 129 species in 12 genera are found mostly on the reefs of the Atlan ...

belonging to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Chaetodontidae. It is native to the tropical

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by ...

Description

''Chaetodon triangulum'' has a flat triangular shaped body, emphasised when the fins are fully spread, and an elongated snout. Its body is predominantly whitish in colour with many broad, vertical grey

chevron Chevron (often relating to V-shaped patterns) may refer to: Science and technology * Chevron (aerospace), sawtooth patterns on some jet engines * Chevron (anatomy), a bone * ''Eulithis testata'', a moth * Chevron (geology), a fold in rock lay ...

-shaped bands along the sides, Its mouth is orange, and there is a brownish orange vertical band through the eye, which grows brighter orange closer to the top of the head widening as it extends rearward on the base of the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

in adults. The caudal peduncle is black, as is the caudal fin but its margins are yellow. The dorsal fin has 11-12 spines and 23-26 soft rays while the

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...

contains 3 spines and 20-21 soft rays. This species attains a maximum

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

of .

Distribution

''Chaetodon triangulum'' has a wide distribution in the Indian Ocean from the coast of tropical East Africa east to the

Andaman Sea The Andaman Sea (historically also known as the Burma Sea) is a marginal sea of the northeastern Indian Ocean bounded by the coastlines of Myanmar and Thailand along the Gulf of Martaban and west side of the Malay Peninsula, and separated fro ...

and along the Indian Ocean coastlines of Sumatra and

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

. It also appears at the Seribu Islands and has been reported near Bali.

Habitat and biology

''Chaetodon triangulum'' is found in lagoon and seaward reefs where it is strongly associated with corals in the genus ''

Acropora ''Acropora'' is a genus of small polyp stony coral in the phylum Cnidaria. Some of its species are known as table coral, elkhorn coral, and staghorn coral. Over 149 species are described. ''Acropora'' species are some of the major reef corals r ...

'', especially

staghorn coral The staghorn coral (''Acropora cervicornis'') is a branching, stony coral with cylindrical branches ranging from a few centimetres to over two metres in length and height. It occurs in back reef and fore reef environments from depth. The upper ...

s. This is a

territorial A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or an ...

species which lives in pairs, although solitary juveniles hide among coral branches. Triangle butterflyfish are obligate corallivores that feed primarily on ''Acropora'' corals. They defend patches of these corals and actively chase other butterflyfishes from these territories and the food supply it contains.

Taxonomy

''Chaetodon triangulum'' was first formally described in 1831 by the

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with France ...

anatomist Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...

Georges Cuvier (1769-1832) with the

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

given as Jakarta.

References

{{Taxonbar, from=Q2138908 Fish of Thailand Fish described in 1831 Taxa named by Georges Cuvier Fish of the Indian Ocean

triangulum Triangulum is a small constellation in the northern sky. Its name is Latin for " triangle", derived from its three brightest stars, which form a long and narrow triangle. Known to the ancient Babylonians and Greeks, Triangulum was one of the 4 ...