The blue-cheeked butterflyfish (''Chaetodon semilarvatus'') is a marine

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), ...

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

The bluecheek butterflyfish has a bright yellow body marked with thin vertical red lines. There a greyish patch behind the eyes, whereas most related species have an eye bar. The

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 The fus ...

anal Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving ...

pelvic The pelvis (: pelves or pelvises) is the lower part of an anatomical trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis or pelvic skeleton). ...

and

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 ...

s are yellow. It is a relatively large species of butterflyfish which can attain 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 typical.

Distribution

The bluecheek butterflyfish is found in the north-western Indian Ocean where it occurs in the

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 ...

and 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. ...

, as far east as the coast of Oman.

Habitat and biology

The bluecheek butterflyfish is one of the few fish species to have long-term mates. In the wild, the fish eats hard corals as well as benthic invertebrates. This is a common species which is found in areas with rich coral growth. They are frequently recorded in pairs or in small shoals. They have been known to occasionally hover in a stationary position for long periods beneath ledges of plate corals of the genus ''

Acropora ''Acropora'' is a genus of small polyp stony coral in the phylum Cnidaria. Some of its species are known as table coral, elkhorn coral, and staghorn coral. Over 149 species are described. ''Acropora'' species are some of the major reef corals ...

''. It is oviparous species which forms pairs when spawning. This is normally during the day and the fishes emerge and are active at night. They are found at depths between .

Systematics

The bluecheek butterflyfish was first formally described in 1831 by the French anatomist Georges Cuvier with the type locality given as the Red Sea at Massawa, Eritrea and Al-Luhayya, 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 ...

. In this group, it seems closest to a group containing the blackback butterflyfish (''C. melannotus''), the spot-naped butterflyfish (''C. oxycephalus''), or the peculiar black-wedged butterflyfish (''C. falcula'') and

Pacific double-saddle butterflyfish ''Chaetodon ulietensis'', the Pacific double-saddle butterflyfish or false falcula butterflyfish, is a species of butterflyfish (family Chaetodontidae). It flourishes in coral-rich environments in the central Indo-Pacific region. Their range exte ...

or "false falcula", (''C. ulietensis''). Though the present species does not share their white body with black on the back and

caudal peduncle 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 ...

and even lacks the typical eyestripe of ''Chaetodon'', it has the same tell-tale blue vertical lines as these species.

Footnotes

References

* (2007): Molecular phylogenetics of the butterflyfishes (Chaetodontidae): Taxonomy and biogeography of a global coral reef fish family. '' Mol. Phylogenet. Evol.'' 45(1): 50–68. (HTML abstract) * (2008)
''Chaetodon semilarvatus''
Version of 2008-JUL-24. Retrieved 2008-SEP-01. * (2007): Molecular phylogeny of ''Chaetodon'' (Teleostei: Chaetodontidae) in the Indo-West Pacific: evolution in geminate species pairs and species groups. ''Raffles Bulletin of Zoology Supplement'' 14: 77–86
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External links

* {{Taxonbar, from=Q1281124 Chaetodon Fish described in 1831 Taxa named by Georges Cuvier