Butterflyfish

"Butterfly Fish" redirects here. For the novel, seeButterfly Fish (novel).For an unrelated species, seeFreshwater butterflyfish.

Thebutterflyfishare a group of conspicuoustropicalmarinefishof the familyChaetodontidae;thebannerfishandcoralfishare also included in this group. The approximately 129speciesin 12generaare found mostly on thereefsof theAtlantic,Indian,andPacific Oceans.A number ofspecies pairsoccur in the Indian and Pacific Oceans, members of the huge genusChaetodon.

Butterflyfishes Temporal range:
Various examples of butterflyfishes, along with angelfishes
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Suborder:	Percoidei
Family:	Chaetodontidae Rafinesque,1810
Genera
About 10, seetext
Synonyms
Chaetodontinae(but seetext)

Butterflyfish look like smaller versions of angelfish (Pomacanthidae), but unlike these, lackpreoperclespines at thegill covers.Some members of the genusHeniochusresemble theMoorish idol(Zanclus cornutus) of themonotypicZanclidae. Among theparaphyleticPerciformes,the former are probably not too distantly related to butterflyfish, whereas the Zanclidae seem far less close.

Description and ecology

Aschooloffalse Moorish idols,Heniochus diphreutes

Butterflyfish mostly range from 12 to 22 cm (4.7 to 8.7 in) in length. The largest species, thelined butterflyfishand thesaddle butterflyfish,C. ephippium,grow to 30 cm (12 in). The common name references the brightly coloured and strikingly patterned bodies of many species, bearing shades of black, white, blue, red, orange, and yellow. Other species are dull in colour. Butterflyfish are a boundless, different group of marine percoids with delegates on practically all coral reef frameworks and in every single tropical ocean. Their bright and color patterns have drawn in much consideration, creating an abundance of data about their conduct and environment.Many haveeyespotson their flanks and dark bands across their eyes, not unlike the patterns seen onbutterflywings.Their deep,laterallynarrow bodies are easily noticed through the profusion of reef life. The conspicuous coloration of butterflyfish may be intended for interspecies communication. Butterflyfish have uninterrupteddorsal finswithtail finsthat may be rounded or truncated, but are never forked.

Generallydiurnaland frequenting waters less than 18 m (59 ft) deep (though some species descend to 180 m (590 ft), butterflyfish stick to particular home ranges. Thesecorallivoresare especially territorial, forming pairs and staking claim to a specific coral head. Contrastingly, thezooplanktonfeeders form large conspecific groups. By night, butterflyfish hide in reef crevices and exhibit markedly different coloration.

Their coloration also makes them popularaquariumfish. However, most species feed oncoralpolypsandsea anemones.Balancing the relative populations of prey and predator is complex, leading hobby aquarists to focus on the few generalists and specialistzooplanktonfeeders.

Butterflyfish are pelagic spawners; that is, they release many buoyant eggs into the water, which become part of theplankton,floating with the currents until hatching. The fry go through a tholichthys stage, wherein the body of the postlarvalfish is covered in large, bony plates extending from the head. They lose their bony plates as they mature.Only one other family of fish, the scats (Scatophagidae) express such an armored stage.

Taxonomy, systematics and evolution

The Chaetodontidae can be, but are not usually, divided into two lineages that arguably aresubfamilies.The subfamily nameChaetodontinaeis a little-used leftover from the period when thePomacanthidaeand Chaetodontidae were united under the latter name as a single family. Hence, Chaetodontinae is today considered ajunior synonymof Chaetodontidae. In any case, one lineage of Chaetodontidae (in the modern sense) contains the "typical" butterflyfish aroundChaetodon,while the other unites the bannerfish and coralfishgenera.As thePerciformesare highlyparaphyletic,the precise relationships of the Chaetodontidae as a whole are badly resolved.

Chaetodontidae is classified within thesuborderPercoideiby the 5th edition ofFishes of the World,but they are placed in an unnamedcladewhich sits outside thesuperfamilyPercoidea.This clade contains 7 families which appear to have some relationship toAcanthuroidei,Monodactylidae,andPriacanthidae.Other authorities have paced the family in the orderChaetodontiformesalongside the familyLeiognathidae.

Before DNA sequencing, thetaxonomywas confused about whether to treat these as species orsubspecies.Also, numeroussubgenerahave been proposed for splitting out ofChaetodon,and it is becoming clear how to subdivide the genus if that is desired.

Thefossilrecord of this group is marginal. Their restriction tocoral reefsmeans their carcasses are liable to be dispersed byscavengers,overgrown bycorals,and any that do fossilize will not long surviveerosion.However,Pygaeus,a verybasalfossil from the mid- to lateEoceneofEurope,dates from around theBartonian40–37 million years ago (Mya). Thus, the Chaetodontidae emerged probably in the early to mid-Eocene. A crudemolecular clockin combination with the evidence given byPygaeusallows placement of the initial split between the two main lineages to the middle to late Eocene, and together with the few other fossils, it allows the deduction that most living genera were probably distinct by the end of thePaleogene23 Mya.

Genera

The bannerfish-coralfish lineage can be further divided in two groups; these might be consideredtribes,but have not been formally named. Genera are listed in order of the presumedphylogeny,from the most ancient to the youngest:

Bannerfish/coralfish lineage 1:

• AmphichaetodonBurgess,1978
• CoradionKaup,1860
• ChelmonCloquet,1817
• ChelmonopsBleeker,1876

Bannerfish/coralfish lineage 2:

• ForcipigerJordan&McGregor,1898
• HemitaurichthysBleeker, 1876
• HeniochusCuvier,1816
• JohnrandalliaNalbant,1974

The"typical" butterflyfishesmay eventually come to contain more genera; seeChaetodon:

• ChaetodonLinnaeus,1758
• ParachaetodonBleeker, 1874
• PrognathodesGill,1862
• RoaJordan, 1923

Timeline

Gallery

• 
  Copperband butterflyfish,Chelmon rostratus
• 
  The enigmaticJohnrandallia nigrirostris
• 
  Sunburst butterflyfish,(sometimes placed inLepidochaetodon)
• 
  Bluelashed butterflyfish,Chaetodon bennetti (sometimes placed inMegaprotodon)

Further reading

• Pratchett, Morgan S. & Berumen, Michael L. & Kapoor, B.G. [Editors]:Biology of Butterflyfishes.CRC Press, 2014.ISBN978-1-4665-8290-3

References

General

• Fessler, Jennifer L. & Westneat, Mark W.(2007): Molecular phylogenetics of the butterflyfishes (Chaetodontidae): Taxonomy and biogeography of a global coral reef fish family.Mol. Phylogenet. Evol.45(1): 50–68.doi:10.1016/j.ympev.2007.05.018(HTML abstract)
• FishBase[2008]:Family Chaetodontidae – Butterflyfishes.Retrieved 2008-SEP-02.
• Hsu, Kui-Ching; Chen, Jeng-Ping & Shao, Kwang-Tsao(2007): Molecular phylogeny ofChaetodon(Teleostei: Chaetodontidae) in the Indo-West Pacific: evolution in geminate species pairs and species groups.Raffles Bulletin of Zoology Supplement14:77–86.PDF fulltextArchived2007-08-11 at theWayback Machine
• Sepkoski, Jack(2002): [Chaetodon].In:A compendium of fossil marine animal genera.Bulletins of American Paleontology364:560.HTML database excerpt

Specific