The raccoon butterflyfish (''Chaetodon lunula''), also known as the crescent-masked butterflyfish, lunule butterflyfish, halfmoon butterflyfish, moon butterflyfish, raccoon butterfly, raccoon, raccoon coralfish, and redstriped butterflyfish, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

, a

butterflyfish The butterflyfish are a group of conspicuous tropical ocean, 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 ...

belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Chaetodontidae. It is found in the Indian and Pacific Oceans.

Taxonomy

''Chaetodon lunula'' was first formally described as ''Pomacentrus lunula'' in 1802 by the

french French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

Bernard Germain de Lacépède (1756–1825) with the type locality given as "the Indian Ocean". It belongs to the large

subgenus In biology, a subgenus ( 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 the ge ...

''Rabdophorus'' which might warrant recognition as a distinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

. In this group, its closest relative is probably the very similar Red Sea raccoon butterflyfish or

diagonal butterflyfish The diagonal butterflyfish (''Chaetodon fasciatus''), also known as the Red Sea raccoon butterflyfish, is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is found in the Red Sea and western Indian ...

, ''C. fasciatus''. Other close relatives appear to be the

black butterflyfish The Black Butterflyfish (''Chaetodon flavirostris''), also known as the dusky butterflyfish, is a species of marine ray-finnedfish, a butterflyfish belonging to the family Chaetodontidae. It is native to the Pacific Ocean. Description The black ...

, '' C. flavirostris''), Philippine butterflyfish, ''C. adiergastos'', and perhaps also the unusual redtail butterflyfish, ''C. collare''. Although the coloration of this group varies greatly, they are all largish butterflyfishes with an oval outline, and most have a pattern of ascending oblique stripes on the flanks. Except in the red-tailed butterflyfish, there is at least a vestigial form of the "

raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...

" mask, with a white space between the dark crown and eye areas.

Description

''Chaetodon lunula'' can reach a length of 20 cm (nearly 8 in). These large butterflyfishes have an oval outline, with a pattern of ascending oblique reddish stripes on the flanks and black and white bands over the face and eyes, similar to the "

" mask (hence the common name). They show a black spot on the caudal peduncle and oblique yellow stripes behind the head. They have 10–14 dorsal spines and 3 anal spines.

Biology

''Chaetodon lunula'' is a nocturnal species that usually lives in small groups. Adults feed mainly on nudibranchs and small invertebrates, but also on algae and coral polyps.

Distribution

This species can be found widely throughout the tropical

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 ...

region (East Africa to the Hawaiian and Marquesan islands, north to southern Japan) and in the southeast

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

(South Africa). Chaetodon lunula on Israeli stamp

Habitat

This species prefers seaward reefs and shallow reef flats of lagoon, at a depth of over 30 m.

In the aquarium

The raccoon butterflyfish is generally not aggressive towards other fish, with the exception of

lionfish ''Pterois'' is a genus of venomous fish, venomous marine fish, commonly known as the lionfish, native to the Indo-Pacific. It is characterized by conspicuous aposematism, warning coloration with red or black bands and ostentatious dorsal fins tip ...

and

triggerfish Triggerfish are about 40 species of often brightly colored marine ray-finned fishes belonging to the family Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest speci ...

. In captivity, the typical lifespan of a raccoon butterflyfish is five to seven years. It has been observed as a beneficial

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

of ''

Aiptasia ''Aiptasia'' is a genus of a symbiotic cnidarian belonging to the subphylum Anthozoa (sea anemones, corals). ''Aiptasia'' is a widely distributed genus of temperate and tropical sea anemones of benthic lifestyle typically found living on mangrove ...

'' and ''

Majano Majano () is a (municipality) in the Regional decentralization entity of Udine in the Italian region of Friuli-Venezia Giulia, located about northwest of Trieste and about northwest of Udine. Majano borders the following municipalities: Buja ...

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

s. They will eliminate this nuisance pest within a two- to six-week period depending on the anemone population and size of the tank; however, they will eagerly feed on any soft corals and may cause more harm than good to the decoration. In a confined environment, this species is prone to succumbing to "marine ich", infection by the

ciliate The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a ...

Cryptocaryon irritans ''Cryptocaryon irritans'' is a species of ciliates that parasitizes marine fish, causing marine white spot disease or marine ich (pronounced ''ick''). It is one of the most common causes of disease in marine aquaria. Taxonomy ''Cryptocaryon i ...

''.

References

External links

* {{Taxonbar, from=Q1759410 Chaetodon Fish of Hawaii