The reef butterflyfish (''Chaetodon sedentarius''). also known as the least butterflyfish, Atlantic butterflyfish, butterbun or school mistress, 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 ...

of 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 western

Atlantic Ocean 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 ...

Description

The reef butterflyfish has a strongly compressed, oval body which is more rectangular in shape than other Western Atlantic butterflyfishes. Its short, pointed snout has no cheekbones and the mouth is situated at its end. The upper body and upper head are yellow fading to white towards the belly and lower head. There is a vertical black bar which runs through the eye and another along the rear edge of the body and

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 remainder of the dorsal and anal fins, and 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 se ...

is yellow. The juveniles have a less distinct rear black bar and it may just be two spots. The dorsal fin has 13-14 spines and 20-22 soft rays while the anal fin contains 3 spines and 17-19 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

The reef butterflyfish is native to the warmer waters of the Western Atlantic Ocean from

São Paulo state SAO or Sao may refer to: Places * Sao civilisation, in Middle Africa from 6th century BC to 16th century AD * Sao, a town in Boussé Department, Burkina Faso * Saco Transportation Center (station code SAO), a train station in Saco, Maine, U.S ...

north as far as

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

, including the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

and

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. It has occurred around the

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but has not been able to establish populations there.

Habitat and biology

The reef butterflyfish lives on rocky and coral reefs to depths of . Its compressed body means that it can forage by darting in and out of the coral, the small, protractile mouth is a further adaptation to finding food within the coral. The mouth is equipped with long and thin teeth which are flattened, and a little recurved at their tips, These are used to scrape and nip at small invertebrates such as

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are mad ...

, shrimps and

amphipods Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descri ...

. It is also reported to feed on the eggs of the

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(''Abudefduf saxatilis'') It can be quite nimble when feeding, frequently swimming upside down to get to prey hiding in crevices. The adults of the reef butterflyfish are most frequently encountered in pairs and may be monogamous and show a strong pair bond.

Spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquati ...

takes place at dusk following a lengthy and energetic courtship involving circling before swimming upwards and releasing the eggs and

milt Milt is the seminal fluid of fish, mollusks, and certain other water-dwelling animals which reproduce by spraying this fluid, which contains the sperm, onto roe (fish eggs). It can also refer to the sperm sacs or testes that contain the semen. ...

. Each female will release 3–4,000 eggs at each spawning. The small, transparent, pelagic eggs hatch within 24 hours and initially the larval fish are tiny, translucent and silvery in colour. Butterflyfish larvae, along with the

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, are unusual in that they are armoured, bony plates on the head and body form this armour and this is called the tholichthys stage. The tholichys stage lasts until the length of the larvae reaches when they settle on the substrate at night. By the next day they have become juveniles and will hide in crevices until they are large enough to be reasonably secure from predators, emerging into shallow water next to channels or ledges. The reef butterflyfish has many predators, mostly larger fish such as snappers,

grouper Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" is u ...

s and

moray eel Moray eels, or Muraenidae (), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are f ...

s, and it normally flees when attacked but if this is not possible they will adopt a defensive posture and face their pursuer with their head lowered and the spines in the dorsal fin fully raised.

Taxonomy and etymology

The reef butterflyfish was first formally described in 1860 by the

Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...

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 ...

Felipe Poey (1799-1891) with the type locality given as Cuba. The specific name ''sedentarius'' means "sedentary" but its usage is not explained but it is thought that it may be to distinguish this species from 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 ...

species that

Alphone Guichenot Antoine Alphonse Guichenot (31 July 1809 in Paris – 17 February 1876 in Cluny) was a French zoologist who taught, researched, and participated in specimen collecting trips on behalf of the ''Muséum national d'histoire naturelle'' (Paris), in ...

misidentified this species for '' c. vagabundus''. ''C. sedentarius'' is classified 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 ...

''Exornator'', if the genus ''

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, ''Exornator'' might become a subgenus of ''Lepidochaetodon''.

Utilisation

The reef butterflyfish is readily available 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. It is a species which is easy to keep in captivity, and may even be suitable for beginners.

References

External links

* * {{Taxonbar, from=Q1054432 reef butterflyfish Fauna of the Southeastern United States Fish of the Western Atlantic Taxa named by Felipe Poey reef butterflyfish