Foureye butterflyfish
Encyclopedia
The Four-eyed Butterflyfish (Chaetodon capistratus) is a butterflyfish
(family
Chaetodontidae). It is alternatively called the Foureye Butterflyfish. This species
is found in the Western Atlantic from Massachusetts
, USA and Bermuda
to the West Indies and northern South America
.
Chaetodon capistratus is the type species
of Chaetodon
. If this genus
is split up as some have proposed, it will retain its present name like its closest relatives, which include the Banded Butterflyfish
(C. striatus) and the Spot-finned Butterflyfish (C. ocellatus).
and a small mouth with tiny, bristle like teeth. The body is light grey, sometimes with a yellowish hue, and dark forward-pointing chevrons. The ventral fins 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 confusing the back end of the fish for the front end. The Four-eyed 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 tricks the predator into believing that the fish will flee tail first. When escape is not possible, a Four-eyed 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.
Four-eyed butterflyfish usually frequent shallow inshore waters, where they feed on a variety of invertebrate
s, mainly zoantharia
ns, polychaete
worms, gorgonians and tunicate
s. 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
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. Found mostly on the reefs of the Atlantic, Indian and Pacific Oceans, there are approximately 120 species in 10 genera...
(family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Chaetodontidae). It is alternatively called the Foureye Butterflyfish. This species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
is found in the Western Atlantic from Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
, USA and Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...
to the West Indies and northern South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
.
Chaetodon capistratus is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of Chaetodon
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 might warrant recognition as distinct genera.Several subgenera...
. If this genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
is split up as some have proposed, it will retain its present name like its closest relatives, which include the Banded Butterflyfish
Banded butterflyfish
The banded butterflyfish is a butterflyfish found in the western Atlantic Ocean from Brazil to Bermuda.The name is derived from the dark vertical bands on the fish's body. This, combined with a vertical, black bar through the eye, is designed to confuse predators....
(C. striatus) and the Spot-finned Butterflyfish (C. ocellatus).
Description and ecology
Four-eyed butterflyfish are deep-bodied and laterally compressed, with a single dorsal finDorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
and a small mouth with tiny, bristle like teeth. The body is light grey, sometimes with a yellowish hue, and dark forward-pointing chevrons. The ventral fins 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
Eyespot (mimicry)
An eyespot is an eye-like marking. They are found on butterflies, reptiles, birds and fish. In members of the Felidae family , the white circular markings on the backs of the ears are termed ocelli, and they are functionally similar to eyespots in other animals.Eyespots may be a form of...
. A black vertical bar on the head runs through the true eye, making it hard to see.
This pattern may result in a predator confusing the back end of the fish for the front end. The Four-eyed 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 tricks the predator into believing that the fish will flee tail first. When escape is not possible, a Four-eyed 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.
Four-eyed butterflyfish usually frequent shallow inshore waters, where they feed on a variety of invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, mainly zoantharia
Zoantharia
Zoanthids 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 colonizing formations and in numerous colors...
ns, polychaete
Polychaete
The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...
worms, gorgonians and tunicate
Tunicate
Tunicates, also known as urochordates, are members of the subphylum Tunicata, previously known as Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that is classified within the phylum Chordata. While most tunicates live on the ocean floor, others such...
s. 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