''Chaetodon mesoleucos'', the white-faced butterflyfish, is a species off 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 north western Indian Ocean.

Description

''Chaetodon mesoleucos'' has a bluish white anterior part of the body with a vertical black band running through the eye. The rest of the body is pale grey in colour marked with numerous vertical black lines. The

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

is black with a white on the inner margin near the caudal peduncle. This species attains a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

of , although is more common.

Distribution

''Chaetodon mesoleucos'' is found in the northwestern Indian Ocean. It occurs from the central

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

, into the

Gulf of Aden The Gulf of Aden (; ) 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 Channel, the Socotra Archipelago, Puntland in Somalia and Somaliland to the south. ...

and around

Socotra Socotra, locally known as Saqatri, is a Yemeni island in the Indian Ocean. Situated between the Guardafui Channel and the Arabian Sea, it lies near major shipping routes. Socotra is the largest of the six islands in the Socotra archipelago as ...

Habitat and biology

''Chaetodon mesoleucos'' occurs at depths between , inhabiting coral reefs where they occur in pairs. They are thought to feed mainly on coral polyps but will eat a variety of benthic invertebrates. Little is known about the biology of this species.

Systematics

''Chaetodon mesoleucos'' was first formally described in 1775 by the Swedish-speaking Finnish

explorer Exploration is the process of exploring, an activity which has some Expectation (epistemic), expectation of Discovery (observation), discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organis ...

, orientalist,

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 ...

Peter Forsskål (1732-1763), his description was published in 1775 by his companion on his expedition to Yemen, the orientalist and mathematician

Carsten Niebuhr Carsten Niebuhr, or Karsten Niebuhr (17 March 1733 Cuxhaven, Lüdingworth – 26 April 1815 Meldorf, Dithmarschen), was a German mathematician, Cartography, cartographer, and Geographical exploration, explorer in the service of Denmark-Norway. He ...

. The type locality was given as Al-Mukhā in Yemen. 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 ...

Utilisation

''Chaetodon mesoleucos'' is uncommon in the aquarium trade. However, it is not a difficult species to keep in captivity.

References

{{taxonbar, from=Q2389373 mesoleucos Fish described in 1775 Taxa named by Peter Forsskål