The foureye butterflyfish (''Chaetodon capistratus'') is 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 ...

(

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 alternatively called the four-eyed butterflyfish. This

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 ...

is found in the Western

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

from

Massachusetts Massachusetts (Massachusett language, Massachusett: ''Muhsachuweesut assachusett writing systems, məhswatʃəwiːsət'' English: , ), officially the Commonwealth of Massachusetts, is the most populous U.S. state, state in the New England ...

, USA and

Bermuda ) , anthem = "God Save the King" , song_type = National song , song = " Hail to Bermuda" , image_map = , map_caption = , image_map2 = , mapsize2 = , map_caption2 = , subdivision_type = Sovereign state , subdivision_name = , e ...

to the

West Indies The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greater A ...

and northern

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. ''Chaetodon capistratus'' 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 ...

of ''

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 ...

''. If this

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

is split up as some have proposed, it will retain its present name like its closest relatives, which include the

banded butterflyfish The banded butterflyfish (''Chaetodon striatus'') is a species of marine ray-finned fish, a butterflyfish found in the tropical western Atlantic Ocean from Brazil to Bermuda. Common names include the banded butterflyfish, the butterbun, the butte ...

(''C. striatus'') and the spot-finned butterflyfish (''C. ocellatus'').

Description and ecology

Foureye butterflyfish are deep-bodied and laterally compressed, with a single

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 ...

and a small mouth with tiny, bristle like teeth. The body is light grey, sometimes with a yellowish hue, and dark forward-pointing

chevron Chevron (often relating to V-shaped patterns) may refer to: Science and technology * Chevron (aerospace), sawtooth patterns on some jet engines * Chevron (anatomy), a bone * '' Eulithis testata'', a moth * Chevron (geology), a fold in rock ...

s. The

ventral 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 ...

s are yellow. The species gets its common name from a large dark spot on the rear portion of each side of the body. This spot is surrounded by a brilliant white ring, resembling an eye. A black vertical bar on the head runs through the true eye, making it hard to see. This pattern may result in a

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

confusing the back end of the fish for the front end. The foureye butterflyfish's first instinct when threatened is to flee, putting the false eye spot closer to the predator than the head. Most predators aim for the eyes, and this false eye spot may in

automimicry In zoology, automimicry, Browerian mimicry, or intraspecific mimicry, is a form of mimicry in which the same species of animal is imitated. There are two different forms. In one form, first described by Lincoln Brower in 1967, weakly-defended m ...

trick the predator into believing that the fish will flee tail first. Other potential functions of the eye spot exist. The eye spots are larger and more variable than the real eye and eye spot shape varies from vertically oval in young to more circular in adults. These features suggest other possible functions of the eye spot including: intimidating prey, altering predation reaction distances, disorientating predators, serving as a general warning, or for social communication. When escape is not possible, a foureye butterflyfish will sometimes turn to face its aggressor, head lowered and spines fully erect, like a bull about to charge. This may serve to intimidate the other animal or may remind the predator that the butterflyfish is much too spiny to make a comfortable meal. Foureye butterflyfish usually frequent shallow inshore waters, where they feed on a variety of

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 chordate ...

s, mainly

zoantharia Zoanthids ( order Zoantharia also called Zoanthidea or Zoanthiniaria) are an order of cnidarians commonly found in coral reefs, the deep sea and many other marine environments around the world. These animals come in a variety of different coloniz ...

ns,

sea anemone Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...

s, scleractinians,

polychaete Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that ...

worms, gorgonians,

tunicate A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ca ...

crustacean 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 ...

s and fish eggs. This fish is known for its uncanny ability to swim in and around coral heads and reefs. They are able to find their way through the most intricate passages by swimming on its side or even upside down. Like its relatives they mate for life and therefore they will often be seen in pairs. They are one of a few fish that mate for life.

Gallery

File:Chaetodon capistratus.png, Chaetodon capistratus (foureye butterflyfish) image from the Smithsonian Tropical Research Institute File:Chaetodon capistratus2.jpg, Chaetodon capistratus File:Four-Eye Butterflyfish.jpg, Foureye butterflyfish

References

External links

* * Video o
Foureye Butterflyfish
- Video taken in Belize off Ambergris Caye. {{Taxonbar, from=Q2165517

foureye butterflyfish The foureye butterflyfish (''Chaetodon capistratus'') is a butterflyfish (family Chaetodontidae). It is alternatively called the four-eyed butterflyfish. This species is found in the Western Atlantic from Massachusetts, USA and Bermuda to the Wes ...

Fish of the Eastern United States Fish of the Caribbean