The oval butterflyfish (''Chaetodon lunulatus''), red-finned butterflyfish or redfin butterflyfish, is a

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), ...

of 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

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

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

from Eastern Indonesia to the Hawaiian islands. This is one species of a closely related group which includes the blacktail butterflyfish, which is found in the Red Sea and Gulf of Aden, and the melon butterflyfish, which is found in the Indian Ocean.

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

008 008, OO8, O08, or 0O8 may refer to: * "008", a fictional 00 Agent In Ian Fleming's James Bond novels and the derived films, the 00 Section of MI6 is considered the secret service's elite. A 00 (pronounced "Double O") is a field agent who ho ...

''Chaetodon lunulatus''. Retrieved 2008-SEP-01.

Description and characteristics

The blacktail butterflyfish (''C. austriacus''), melon butterflyfish (''C. trifasciatus''), and oval butterflyfish (''C. lunulatus'') are similar in coloration. The former has black

caudal Caudal may refer to: Anatomy * Caudal (anatomical term) (from Latin ''cauda''; tail), used to describe how close something is to the trailing end of an organism * Caudal artery, the portion of the dorsal aorta of a vertebrate that passes into th ...

and

anal 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 o ...

s, while the latter is an

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

species and has a more conspicuous back patch below the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

and a mainly yellow anal fin.Lieske, E. & Myers, R.F. (2004): ''Coral reef guide – Red Sea''. HarperCollins, London. ''Chaetodon lunulatus'' can grow up to 14 cm long. It has about 13-14 dorsal spines, 20-22 dorsal soft rays, three anal spines, and 18-21 anal soft rays. Together with the black-tailed and melon butterflyfishes, and probably also the somewhat aberrant Arabian butterflyfish ('' C. melapterus''), it makes up the

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 ...

''Corallochaetodon''. They are probably quite close to the subgenus ''"Citharoedus"'' (the name is a

junior homonym In biology, a homonym is a name for a taxon that is identical in spelling to another such name, that belongs to a different taxon. The rule in the International Code of Zoological Nomenclature is that the first such name to be published is the s ...

of a

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

genus), which contains the scrawled butterflyfish (''C. meyeri''). Like that group, they might be separated in ''Megaprotodon'' if the

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 ...

Chaetodon ''Chaetodon'' is a tropical fish genus in the family (biology), family Chaetodontidae. Like their relatives, they are known as "butterflyfish". This genus is by far the largest among the Chaetodontidae, with about 90 living species included here, ...

'' is split up.

Habitat and range

Oval butterflyfish can be found in the Pacific Ocean from Japan and Australia to the North and South and Hawaii and the Tuamotu Islands to the East. They are benthopelagic and can be found in coral reefs in the tropics. They can be found at a depth of 3 to 30 meters in

coral Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

-rich

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

s and semi-protected seaward

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 component, abiotic (non-living) processes such as deposition (geol ...

s. Small juveniles are secretive and hide in

Ecology and behavior

Diet

The butterflyfish species feeds almost exclusively on hard corals.Pratchett, M.S. (2005). Dietary overlap among coral-feeding butterflyfishes (Chaetodontidae) at Lizard Island, northern Great Barrier Reef. Marine Biology, 148, 373–382. doi: 10.1007/s00227-005-0084-4 The oval butterflyfish is a widespread corallivore and has been found to feed on 51 different types of coral, including '' Acropora florida'', '' A. gemmifera'', '' A. hyacinthus'', ''A. intermedia'', and ''

Pocillopora damicornis ''Pocillopora damicornis'', commonly known as the cauliflower coral or lace coral, is a species of stony coral in the family Pocilloporidae. It is native to tropical and subtropical parts of the Indian and Pacific Oceans. Description ''P. damic ...

''.

Effects of coral bleaching

Coral bleaching Coral bleaching is the process when corals become white due to loss of Symbiosis, symbiotic algae and Photosynthesis, photosynthetic pigments. This loss of pigment can be caused by various stressors, such as changes in water temperature, light, ...

has been shown to affect ''Chaetodon lunulatus''. A 2004 study found a noticeable decline in the physiological condition of the oval butterflyfish before and immediately after a coral bleaching event, possibly leading to reductions in survivorship.Pratchett, M.S., Wilson, S.K. and Baird, A.H. (2006), Declines in the abundance of Chaetodon butterflyfishes following extensive coral depletion. Journal of Fish Biology, 69, 1269-1280. doi:10.1111/j.1095-8649.2006.01161.x A 2006 study found a significant decline in the abundance of various species of butterflyfish (including ''C. lunulatus'') after a bleaching event in the

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system, composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

. Only obligate coral-feeding butterflyfishes, such as ''C. lunulatus'', and not facultative or non-coral feeders displayed reductions in abundance. It has been suggested that these declines were due to starvation and death resulting from a lack of coral prey.

Reproduction and mating

The oval butterflyfish is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

and has little

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

.Yabuta, S. (2008). Signal function of tail-up posture in the monogamous butterflyfish (Chaetodon lunulatus): dummy experiments in the field. Ichthyological Research, 55, 299–302. doi: 10.1007/s10228-007-0027-9 In ''C. lunulatus'', both solitary living and pair bonding occurs amongst individuals.Nowicki, J. P., O'Connell, L. A., Cowman, P. F., Walker, S., Coker, D. J., & Pratchett, M. S. (2018). Variation in social systems within Chaetodon butterflyfishes, with special reference to pair bonding. PLOS ONE, 13 (4), e0194465. doi: 10.1371/journal.pone.0194465 Studies have found that heterosexual pairing predominates, most likely to facilitate reproduction. Partner fidelity appears long-lasting, with one study reporting that individuals remained paired for up to seven years. In these pair-bonds, females feed more frequently, while males tend to take the leading position when swimming in tandem. The pairs display a high level of parallel and proximate (1.5m) swimming, and almost always remain in close range (4m).

Territoriality

Butterflyfish defend their territories against conspecifics. A tail-up display is a common antagonistic behavior in the ''Chaetodon'' species.Yabuta, S. (2000). Behaviors in agonistic interaction of the butterflyfish (Chaetodon lunulatus). Journal of Ethology, 18, 11–15. doi: 10.1007/s101640070018 It is performed towards conspecifics in territorial disputes as well as in non-agonistic interactions with a pair partner.Yabuta, S. (1999). Behavioral rules and tail-up display in extra- and intra-pair interactions of the butterflyfish, Chaetodon lunulatus. Journal of Ethology, 17, 79–86. doi: 10.1007/BF02769301 ''C. lunulatus'' may attack individuals when they do not perform the tail-up display. In territorial interactions, the fish display behavioral patterns such as encircling, staring, tail-up display, two-piled-tops fighting, parallel swimming, chasing, rushing, fleeing, and attacking. Fatal fighting only occurs over mating resources but not for resources such as shelter or food.

References

External links

* {{Taxonbar, from=Q3393835 Chaetodon Fish of Hawaii