The diagonal butterflyfish (''Chaetodon fasciatus''), also known as the Red Sea raccoon butterflyfish, is a

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 ...

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 Atlant ...

belonging to 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

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...

and western Indian Ocean.

Description

The diagonal butterflyfish has a yellow body marked with 11 diagonal stripes. On the head there is a vertical black band through the eye and an incomplete white band on the forehead. The dorsal, anal, and

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 ...

s are yellow. This species attains a maximum total length of .

Distribution

The diagonal butterflyfish is found in the northwestern Indian Ocean. It has been recorded from the Red Sea and the

Gulf of Aden The Gulf of Aden ( ar, خليج عدن, so, Gacanka Cadmeed 𐒅𐒖𐒐𐒕𐒌 𐒋𐒖𐒆𐒗𐒒) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channe ...

south as far as Kenya.

Habitat and biology

Diagonal butterflyfish are found over and around

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...

s, on which they feed. They have also been observed feeding on gelatinous zooplankton, such as jellyfish (

Scyphozoa The Scyphozoa are an exclusively marine class of the phylum Cnidaria, referred to as the true jellyfish (or "true jellies"). The class name Scyphozoa comes from the Greek word ''skyphos'' (), denoting a kind of drinking cup and alluding to the ...

) and comb jellies ( Ctenophora).

Systematics

The diagonal butterflyfish was first formally described in 1775 by the

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

speaking Finnish born naturalist Peter Forsskål (1732-1763) with the type locality given as

Jeddah Jeddah ( ), also spelled Jedda, Jiddah or Jidda ( ; ar, , Jidda, ), is a city in the Hejaz region of the Kingdom of Saudi Arabia (KSA) and the country's commercial center. Established in the 6th century BC as a fishing village, Jeddah's pro ...

. It belongs to the large

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 ...

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

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 ...

. In this group, its closest relative is probably the very similar common

raccoon butterflyfish 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 ...

(''C. lunula''). Other close relatives appear to be the black butterflyfish ('' C. flavirostris''),

Philippine butterflyfish The Philippine butterflyfish (''Chaetodon adiergastos''), the Bantayan butterflyfish or panda butterflyfish,, is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is found in the western Pacific, fro ...

(''C. adiergastos''), and perhaps also the unusual red-tailed butterflyfish (''C. collare''). Although the coloration of this group varies quite a lot, 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" mask, with a white space between the dark crown and eye areas.

References

External links

* {{Taxonbar, from=Q1985794 diagonal butterflyfish Fish of the Red Sea diagonal butterflyfish