The saddle butterflyfish (''Chaetodon ephippium'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

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 found in the

Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...

and

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...

s from

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

and the

Cocos-Keeling Islands ) , anthem = "''Advance Australia Fair''" , song_type = , song = , image_map = Australia on the globe (Cocos (Keeling) Islands special) (Southeast Asia centered).svg , map_alt = Location of the Cocos (Keeling) Islands , map_caption = ...

to the Hawaiian,

Marquesan The Marquesas Islands (; french: Îles Marquises or ' or '; Marquesan: ' ( North Marquesan) and ' (South Marquesan), both meaning "the land of men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in t ...

and

Tuamotu The Tuamotu Archipelago or the Tuamotu Islands (french: Îles Tuamotu, officially ) are a French Polynesian chain of just under 80 islands and atolls in the southern Pacific Ocean. They constitute the largest chain of atolls in the world, extendin ...

islands, north to southern

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

, south to Rowley Shoals and

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

It is a large butterflyfish, at up to 30 cm (nearly 12 in) long together with the

Lined Butterflyfish The lined butterflyfish (''Chaetodon lineolatus'') is a species of marine ray-finned fish. a butterflyfish belonging to the family Chaetodontidae, one of the largest species in the genus ''Chaetodon''. It has a wide range from the Red Sea to Sou ...

(''C. lineolatus'') the giant among its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

. In shape it resembles certain

angelfish Angelfish may refer to: *Several groups of fish: **Freshwater angelfish, tropical cichlids of the genus ''Pterophyllum'' **Marine angelfish of the family Pomacanthidae **Atlantic pomfret (''Brama brama''), sold by fishmongers as "angelfish" in Sou ...

es more than most of its relatives. The overall color is yellowish grey, with a large black spot bordered below by a broad white band on the back and wavy blue lines on the lower sides. The throat and the outline of the hind parts is bright yellow. Adults have a filament extending posteriorly from the upper part of the soft portion 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 ...

. The Saddle Butterflyfish is found at depths between 0 and 30 m in

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of Colony (biology), colonies of coral polyp (zoology), polyps held together by calcium carbonate. Most coral reefs are built from stony corals, wh ...

s. It feeds on filamentous

alga Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

e, small

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...

coral polyp Corals are marine invertebrates within the class (biology), class Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important C ...

s, and

fish egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s. The saddle butterflyfish 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 Franc ...

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), the type locality was given as

Bora Bora Bora Bora (French: ''Bora-Bora''; Tahitian: ''Pora Pora'') is an island group in the Leeward Islands. The Leeward Islands comprise the western part of the Society Islands of French Polynesia, which is an overseas collectivity of the French R ...

in the

Society Islands The Society Islands (french: Îles de la Société, officially ''Archipel de la Société;'' ty, Tōtaiete mā) are an archipelago located in the South Pacific Ocean. Politically, they are part of French Polynesia, an overseas country of the F ...

, part of

French Polynesia )Territorial motto: ( en, "Great Tahiti of the Golden Haze") , anthem = , song_type = Regional anthem , song = "Ia Ora 'O Tahiti Nui" , image_map = French Polynesia on the globe (French Polynesia centered).svg , map_alt = Location of French ...

. It belongs to the large

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between ...

''Rabdophorus'' which might warrant recognition as a distinct

. In this group, it appears to represent a distinct lineage, with the Dotted Butterflyfish (''C. semeion'') perhaps the only somewhat closely related species. Next closest seems to be a group including the Black-backed Butterflyfish (''C. melannotus''),

Spot-tailed Butterflyfish The Spot-tailed Butterflyfish, ''Chaetodon ocellicaudus'', is a species of marine ray-finned fish, a butterflyfish belonging to the family (biology), family Chaetodontidae. It is found in the central Indo- west Pacific region from Malaysia to New ...

(''C. ocellicaudus'') and Yellow-dotted Butterflyfish (''C. selene''), but these are already so distant that their ancestors must have diverged from the Saddle Butterflyfish's soon after the ''Rabdophorus'' lineage started to diversify.

References

External links

* {{Taxonbar, from=Q2697531 Chaetodon Fish of Hawaii Fish described in 1831 Taxa named by Georges Cuvier