''Chaetodon humeralis'', the threebanded 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 found in the eastern Pacific Ocean.

Description

Threebanded butterflyfish yes it is yes it is

''Chaetodon humeralis'' has an oval disc-like body which is strongly compressed and it has a small mouth positioned at the end of a short snout. The colour of the body is white or silvery white with obvious brownish-black bands on the line of the

pectoral 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 ...

and another running in from the base of 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 s ...

, a third brownish-black band runs from the nape down through the eye to the throat. The median fins all have black bands through them. There are 12–13 spines and 18–20 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 c ...

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 15–17 soft rays. The 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 ...

reached is but is more typical.

Distribution

''Chaetodon humeralis'' is found in the Eastern Pacific Ocean, its most northerly occurrence is at

Redondo Beach Redondo Beach (Spanish for ''round'') is a coastal city in Los Angeles County, California, United States, located in the South Bay (Los Angeles County), South Bay region of the Greater Los Angeles area. It is one of three adjacent Beach Cities, b ...

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the wor ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

and from there, its range extends south to Peru. It is also found around the Galapagos Islands of Ecuador, the

Revillagigedo Islands The Revillagigedo Islands ( es, Islas Revillagigedo, ) or Revillagigedo Archipelago are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem. They lie approximately from Socorro Island south and southwest of C ...

of Mexico,

Cocos Island Cocos Island ( es, Isla del Coco) is an island in the Pacific Ocean administered by Costa Rica, approximately southwest of the Costa Rican mainland. It constitutes the 11th of the 13 districts of Puntarenas Canton of the Province of Puntarena ...

in Costa Rica and

Malpelo Island Malpelo is a small oceanic island in the eastern Pacific Ocean, located about west of the Colombian mainland with a military post manned by the Colombian Armed Forces. It consists of a sheer and barren rock with three high peaks, the highe ...

in Colombia.

Habitat and biology

''Chaetodon humeralis'' is strongly associated with rock reefs but has been recorded over a variety of substrates in different parts of its range, including intertidal pools, mangroves and estuaries. It is normally encountered in pairs or small shoals, often near the shore. It will mix in shoals with the Pacific spadefish (''

Chaetodipterus zonatus The Pacific spadefish (''Chaetodipterus zonatus'') is a species of fish of the family Ephippidae. It is native to the eastern Pacific, from San Diego, California to Peru, including is the Galápagos Islands where it is known as Chambo. Appearanc ...

''). It forms pairs to spawn, laying pelagic eggs. It feeds on benthic invertebrates and algae. it has a depth range of but is more common between .

Systematics

''Chaetodon humeralis'' was first formally described in 1860 by the German-born British zoologist Albert Günther (1830–1914) with the type locality given as “the Sandwich Islands” in error for Central America. Some authorities place this species within the nominate subgenus ''Chaetodon'' but others consider it to be ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

''.

References

{{taxonbar, from = Q2913077 humeralis Fish described in 1860 Taxa named by Albert Günther