The Marquesas butterflyfish (''Chaetodon declivis'') 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 hor ...

, 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 Atlant ...

belonging to the

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

Chaetodontidae. It is found in the central Pacific Ocean.

Description

The Marquesas butterflyfish is an attractive species with a silvery-white body marked with black spots and having the upper posterior part of the body with a blackish wedge shaped area. There is also a yellow vertical band running through the eye. 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 conv ...

is yellowish-orange while the

caudal 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 se ...

is yellow. They are known to reach a

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

The Marquesas butterflyfish is restricted to the Central Pacific Ocean, where it is confined to the

Line Islands The Line Islands, Teraina Islands or Equatorial Islands (in Gilbertese, ''Aono Raina'') are a chain of 11 atolls (with partly or fully enclosed lagoons) and coral islands (with a surrounding reef) in the central Pacific Ocean, south of the Hawa ...

in the

United States Minor Outlying Islands The United States Minor Outlying Islands is a statistical designation defined by the International Organization for Standardization's ISO 3166-1 code. The entry code is ISO 3166-2:UM. The minor outlying islands and groups of islands consist ...

, Phoenix Islands in

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 Frenc ...

and Kiribati and Marquesas in French Polynesia.

Habitat and biology

The Marquesas butterflyfish occurs over rocky and sandy bottoms and is an oviparous species which forms pairs for breeding. It is found at depths of between . In the wild this omnivorous species feeds on coral polyps, fanworms,

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

, tunicates and

algae 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 ...

Taxonomy and etymology

The Marquesas butterflyfish was first formally described in 1975 by the American ichthyologist John Ernest Randall with the type locality given as Hanauu Bay on

Fatu Hiva Fatu-Hiva (the "H" is not pronounced, see name section below) is the southernmost island of the Marquesas Islands in French Polynesia, an overseas territory of France in the Pacific Ocean. With Motu Nao as its closest neighbor, it is also the m ...

in the Marquesas Islands. The specific name declivis is Latin for sloping and refers to the diagonally sloping dark patch on the upper posterior part of the body and fins. Populations of similar fishes to ''C. declivis'' in the

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Internati ...

are thought to be hybrids between this species and the

Burgess' butterflyfish Burgess' butterflyfish (''Chaetodon burgessi''), also known as the black & white butterflyfish or black-barred butterflyfish, is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It occurs in the wester ...

(''C. burgessi'').

Utilisation

The Marquesas butterflyfish was formerly caught in numbers for the

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

trade but this has declined since 2006.

References

{{taxonbar, from=Q1054777 Chaetodon Taxa named by John Ernest Randall Fish described in 1975 Fauna of the Marquesas Islands