The black-backed butterflyfish or blackback butterflyfish (''Chaetodon melannotus'') 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 ...

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 ...

(

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 widespread through 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 ...

area from 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 East Africa to

Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands (Savai'i and Upolu); two smaller, inhabited islands (Manono Island, Manono an ...

, to southern Japan and throughout

Micronesia Micronesia (, ) is a subregion of Oceania, consisting of about 2,000 small islands in the western Pacific Ocean. It has a close shared cultural history with three other island regions: the Philippines to the west, Polynesia to the east, and ...

. This fish grows up to 18 cm (ca. 7 in) long, and may live for up to 20 years. When observed at night or when frightened, this species changes color; the dorsal portion of the body turns black except for two white patches. 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, it appears a close relative of the

spot-tailed butterflyfish The Spot-tailed Butterflyfish, ''Chaetodon ocellicaudus'', is a species of marine ray-finned fish, a butterflyfish belonging to the family Chaetodontidae. It is found in the central Indo- west Pacific region from Malaysia to New Guinea, north to ...

(''C. ocellicaudus'') and somewhat less close to the yellow-dotted butterflyfish (''C. selene''). These are all of oval shape, silvery with yellow fins and snout, ascending diagonal stripes, and black markings around the eyes, on the caudal peduncle, and sometimes on the back. Next closest seem the saddle butterflyfish (''C. ephippium'') and the dotted butterflyfish (''C. semeion''), but these are already so distant that their ancestors must have diverged from those soon after the ''Rabdophorus'' lineage started to diversify. These

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

fish are common on

staghorn coral The staghorn coral (''Acropora cervicornis'') is a branching, stony coral with cylindrical branches ranging from a few centimetres to over two metres in length and height. It occurs in back reef and fore reef environments from depth. The upper ...

thickets, they are less seen on exposed parts of

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

s. Black-backed butterflyfish are generally found between 4 and 20 m deep, usually solitary, in pairs during the breeding season. Juveniles are more commonly found inshore, in pairs or traveling in small groups. It feeds primarily on the polyps of soft and hard

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. The Black-backed Butterflyfish is easy to maintain 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 ...

by the standards of its

References

External links

* {{Taxonbar, from=Q2717383 Chaetodon Fish of the Red Sea