The eight-banded Butterflyfish (''Chaetodon octofasciatus''), also known as the eightband butterflyfish or eight-striped butterflyfish, 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 appropriate s ...

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 Atla ...

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

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

region where it is associated with reefs.

Description

The eightband butterflyfish has a flat, circular disk-shaped body with a slightly pointed snout. The body is white turning yellowish towards the belly and is marked with 7 black stripes over the head and the flanks. One runs centrally along the snout and another as a clear black margin to the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

and

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 se ...

s. The third line reaches on to the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

. All of the fins are yellow. There is a white ringed black spot on the caudal peduncle. Some specimens have black or brownish horizontal bars connecting the rear pairs of vertical bars. The background colour is also dependent on the environment inhabited by the fish, with paler, creamier fish in clear waters over coral reefs and the yellower fish being associated with less clear water coloured green by algae near river mouths. There are 10-12 spines and 17-19 soft rays in 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 ...

while the

has 3-4 spines and 14-17 soft rays. This relatively small species of butterflyfish 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

The eightband butterflyfish is found in the eastern Indian Ocean and the western Pacific Ocean from the Maldives, India and Sri Lanka east to the Solomon Islands, north to southern Japan and south to the Scott Reef in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

Habitat and biology

The eightband butterflyfish is found at depths between in

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

s. Adults swim in pairs in

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...

-rich areas of sheltered inshore and

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') a ...

reefs A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

; juveniles can often be seen in groups among ''

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 ...

'' corals. This species feeds exclusively on coral

polyps A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase-shaped body. In solitary polyps, the aboral (opposite to oral) end is ...

Systematics

The eightband butterflyfish was first formally described in 1787 by the

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

Marcus Elieser Bloch (1723–1799) with the type locality given as the INdian Ocean. It is a close relative of the golden butterflyfish (''C. aureofasciatus'') and less close to Rainford's Butterflyfish (''C. rainfordi''). Alongside the three-striped Butterflyfish (''C. tricinctus''), these diverse but always high-bodied species make up the

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 t ...

''Discochaetodon'', of which ''C. octofasciatus'' is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

. They appear to be close relatives of the subgenus ''Tetrachaetodon'' which includes for example the

mirror butterflyfish The mirror butterflyfish or oval-spot butterflyfish (''Chaetodon speculum'') is a species of butterflyfish (family Chaetodontidae). It is found in the Indo-Pacific region from Indonesia to Japan and south to the Great Barrier Reef and Papua New G ...

(''C. speculum'') and together with these would probably go in ''Megaprotodon'' if '' Chaetodon'' is split up.

Utilisation

The eightband butterflyfish is occasionally traded in 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 as an obligate corallivore it is difficult to maintain in the aquarium and they frequently starve.

References

External links

* Chaetodon {{Chaetodontidae-stub