''Chaetodon plebeius'', the blueblotch butterflyfish, bluespot butterflyfish, bluedash butterflyfish or grey-blotched 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 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 native to the Indian and Pacific Oceans.

Description

Chaetodon plebeius has a bright yellow body which is marked with a large horizontal, elongated blue patch on the flanks above the midline. There is a black spot with bluish white margins on the caudal peduncle and a vertical black band which also has bluish white margins running through the eye. 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 ...

anal Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involvin ...

pelvic The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

and

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 ...

s are brilliant yellow. The juveniles do not have the lack the blue patch on the flanks. The dorsal fin contains 13-15 spines and 16-18 soft rays while the anal fin has 4-5 spines and 14-16 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 plebeius'' is found in the western Pacific Ocean and the eastern Indian Ocean. It ranges from Vietnam east to Fiji, north to southern Japan and south to Australia. It is largely absent from Indonesia except from northern Papua. In Australia this species is found from

Rottnest Island Rottnest Island ( nys, Wadjemup), often colloquially referred to as "Rotto", is a island off the coast of Western Australia, located west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, Rottnest is an A-class ...

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 ...

north to the

Dampier Archipelago The Dampier Archipelago is a group of 42 islands near the town of Dampier in the Pilbara, Western Australia. The archipelago is also made up of reefs, shoals, channels and straits and is the traditional home of five Aboriginal language group ...

, it is then found from the northern

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

south as far as Arrawarra Headland near

Coffs Harbour Coffs Harbour is a city on the Mid North Coast of New South Wales, Australia, north of Sydney, and south of Brisbane. It is one of the largest urban centres on the North Coast, with a population of 78,759 as per 2021 census. The Gumbaynggirr ...

in New South Wales. It can also be found on the

Coral Sea The Coral Sea () is a marginal sea of the South Pacific off the northeast coast of Australia, and classified as an interim Australian bioregion. The Coral Sea extends down the Australian northeast coast. Most of it is protected by the Fre ...

reefs,

Elizabeth Reef Elizabeth Reef, located at is a coral reef in the Coral Sea. The reef is separated by a deep oceanic pass, some 47 km wide, from nearby Middleton Reef, both of which are part of the underwater plateau known as the Lord Howe Rise. It i ...

Middleton Reef Middleton Reef is a coral reef in the Coral Sea. It is separated by a deep oceanic pass some 47 km wide from nearby Elizabeth Reef, forming part of the Lord Howe Rise underwater plateau. It is around 230 km from Lord Howe Island and 5 ...

and

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland P ...

in the

Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...

Habitat and biology

''Chaetodon plebeius'' is found in a range of coral reef habitats, from lagoon shallows to the outer reef slopes. It can be found as lone individuals or as pairs. The adults are obligate corallivores, feeding mostly on the polyps of corals of the genus ''

Pocillopora ''Pocillopora'' is a genus of stony corals in the family Pocilloporidae occurring in the Pacific and Indian Oceans.Veron, J.E.N. (2000) Corals of the World. Australian Institute of Marine Science, Townville, Australia. They are commonly called c ...

''. The juveniles have been recorded acting as

cleaner fish Cleaner fish are fish that show a specialist feeding strategy by providing a service to other species, referred to as clients, by removing dead skin, ectoparasites, and infected tissue from the surface or gill chambers. This example of cleaning ...

removing

ectoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s from other fish species. The adults have also been known to feed on ''

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 and a small amount of filamentous green algae. It occurs down to depths of .

Systematics

Chaetodon plebeius was first formally described in 1831 by the French naturalist Georges Cuvier (1769-1832) with the type locality given as “South Seas”. Like the other butterflyfishes which have angular yellow bodies with black eyestripes and a single differently-colored patch, ''C. plebeius'' belongs in 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 ...

''Tetrachaetodon''. Among this group it seems to be the most basal living species. If ''

Chaetodon ''Chaetodon'' is a tropical fish genus in the family Chaetodontidae. Like their relatives, they are known as "butterflyfish". This genus is by far the largest among the Chaetodontidae, with about 90 living species included here, though most migh ...

'' is split up, this subgenus would be placed in ''Megaprotodon''.

References

External links

* {{Taxonbar, from=Q2282187 Fish of Thailand Fish described in 1831 Taxa named by Georges Cuvier Fish of the Indian Ocean Fish of the Pacific Ocean plebeius