The arc-eye hawkfish (''Paracirrhites arcatus''), the ringeye hawkfish, horseshoe hawkfish or whiteline hawkfish, is a species 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

hawkfish Cirrhitidae, the hawkfishes, are a Family (biology), family of marine ray-finned fishes found in tropical seas and which are associated with coral reefs. Taxonomy The Cirrhitidae were first recognised as a family by the Scotland, Scots-born Aust ...

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 ...

Cirrhitidae Cirrhitidae, the hawkfishes, are a family of marine ray-finned fishes found in tropical seas and which are associated with coral reefs. Taxonomy The Cirrhitidae were first recognised as a family by the Scots-born Australian naturalist William ...

. It is found in shallow waters in the tropical

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 ...

reefs 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 (non-living) processes such as deposition of sand or wave eros ...

, resting on coral heads much of the time.

Taxonomy

The arc-eye hawkfish was first formally described in 1829 as ''Cirrhites arcatus'' by the

French French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

Georges Cuvier Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuv ...

with the type locality given as Mauritius. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''arcatus'' means “arched”, an allusion which Cuvier did not explain but it may refer to the horseshoe shaped mark behind the eye. Some authorities treat '' Paracirrhites amblycephalus'' as a valid species but

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.

treats this taxon as a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of ''P. arcatus''.

Description

The arc-eye hawkfish has a relatively deep body, the

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

being around 2.7 times its length. It has a smooth upper preopercular margin and a slightly rounded to truncate

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 ...

. 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 ...

contains 10 spines and 11 soft rays while the anal fin has 3 spines and 6 soft rays, each dorsal fin spine being tipped with a branched cirrus. This species reaches a maximum published total length of . This species has a variable background colour on the body, the typical colour being pale pinkish brown. There is a horseshoe-shaped mark to the rear of the eye that consists of three thin lines. The gill cover has three orange bands set in a light blue area. A white to pink stripe is frequently present from around halfway along the flank and running to the rear.

Distribution and habitat

The arc-eye hawkfish is widespread in the tropical

. Its range extends from is from East Africa from southern Somalia to South Africa eastwards across the Indian Ocean into the Pacific Ocean east to the

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

and

Pitcairn Islands The Pitcairn Islands ( ; Pitkern: '), officially Pitcairn, Henderson, Ducie and Oeno Islands, are a group of four volcanic islands in the southern Pacific Ocean that form the sole British Overseas Territories, British Overseas Territory in the ...

, north to Japan and south to Australia. In Australia it has been recorded from off

Shark Bay Shark Bay () is a World Heritage Site in the Gascoyne region of Western Australia. The area is located approximately north of Perth, on the westernmost point of the Australian continent. UNESCO's listing of Shark Bay as a World Heritage S ...

to the

Muiron Islands The Ningaloo Coast is a World Heritage Site located in the North West Australia, north west coastal region of Western Australia. The heritage-listed area is located approximately north of Perth, along the Indian Ocean, East Indian Ocean. The d ...

and offshore reefs of Western Australia, at

Ashmore Reef The Territory of Ashmore and Cartier Islands is an uninhabited Australian external territory consisting of four low-lying tropical islands in two separate reefs (Ashmore and Cartier), as well as the territorial sea generated by the islands ...

in the

Timor Sea The Timor Sea (, , or ) is a relatively shallow sea in the Indian Ocean bounded to the north by the island of Timor with Timor-Leste to the north, Indonesia to the northwest, Arafura Sea to the east, and to the south by Australia. The Sunda Tr ...

, and from the northern

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, ...

and reefs in the

Coral Sea The Coral Sea () is a marginal sea of the Pacific Ocean, South Pacific off the northeast coast of Australia, and classified as an Interim Biogeographic Regionalisation for Australia, interim Australian bioregion. The Coral Sea extends down t ...

south to the Solitary Islands in

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

. It has also been recorded at the Australian Indian Ocean territories of

Christmas Island Christmas Island, officially the Territory of Christmas Island, is an States and territories of Australia#External territories, Australian external territory in the Indian Ocean comprising the island of the same name. It is about south o ...

and the

Cocos (Keeling) Islands The Cocos (Keeling) Islands (), officially the Territory of Cocos (Keeling) Islands (; ), are an Australian external territory in the Indian Ocean, comprising a small archipelago approximately midway between Australia and Sri Lanka and rel ...

; and the

Tasman Sea The Tasman Sea is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abel Janszoon Tasman, who in 1642 wa ...

locations of

Middleton Reef Middleton Reef is a coral reef in the Coral Sea. It is separated by a deep oceanic pass some 47 km wide from nearby Elizabeth Reef, forming part of the Lord Howe Rise underwater plateau. It is around 230 km from Lord Howe Island an ...

Elizabeth Reef Elizabeth Reef, located at , is a coral reef in the Coral Sea. The reef is separated by a deep oceanic pass, some 47 km wide, from nearby Middleton Reef, both of which are part of the underwater plateau known as the Lord Howe Rise. It is ...

and

Norfolk Island Norfolk Island ( , ; ) is an States and territories of Australia, external territory of Australia located in the Pacific Ocean between New Zealand and New Caledonia, directly east of Australia's Evans Head, New South Wales, Evans Head and a ...

. It is a benthic species associated with coral reefs. It usually can be found in lagoon and seaward reefs, at a depth of , with a maximum of . Paracirrhites arcatus 1

Biology

The arc-eye hawkfish is typically seen sitting motionless on the reef amongst corals. It prefers the heads of ''

Pocillopora ''Pocillopora'' is a genus of stony corals in the family Pocilloporidae occurring in the Pacific and Indian Oceans.Veron, J.E.N. (2000) Corals of the World. Australian Institute of Marine Science, Townville, Australia. They are commonly called ...

'', ''

Stylophora The stylophorans are an extinct, possibly polyphyletic group allied to the Paleozoic Era echinoderms, comprising the prehistoric cornutes and mitrates. It is synonymous with the subphylum Calcichordata. Their unusual appearances have led to a va ...

'' and ''

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 ...

'' corals and is solitary. It preys mostly on shrimps, small fishes, crabs, and other crustaceans. There are main colour morphs and these occur together with the darker fish on basalt dominated areas and the pale fish on corals, the different fish frequently being only a few metres from each other. They form pairs to

spawn Spawn or spawning may refer to: * Spawning, the eggs and sperm of aquatic animals Arts, entertainment and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** ''Spawn: Armageddon' ...

, the pair ascending into the water column to release their

gametes A gamete ( ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. The name gamete was introduced by the Ge ...

Utilisation

The arc-eye hawkfish is collected for, and is a relatively common species in, the aquarium trade.

References

* * Anonym, 2000. Data base of J.L.B. Smith Institute of Ichthyology,

Grahamstown Makhanda, formerly known as Grahamstown, is a town of about 75,000 people in the Eastern Cape province of South Africa. It is situated about northeast of Gqeberha and southwest of East London. It is the largest town in the Makana Local Mun ...

, South Africa. J.L.B. Smith Institute of Ichthyology,

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. * Anonym, 2001. Data base of National Museum of Natural History (

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase a ...

). Smithsonian Institution - Division of Fishes. * Anonym, 2002. Data base of American Museum of Natural History.

American Museum of Natural History The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconn ...

, Central Park West, NY 10024–5192, United States. * Gibbons, S., 1999. Collect fish on stamps. Stanley Gibbons Ltd.,

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

i Ringwood. 418 p. * Munz, F.W. i W.N. McFarland, 1973. The significance of spectral position in the rhodopsins of tropical marine fishes. Vision Res.13:1829-1874. * Randall, J.E., 1986. ''

''. P. 664–666. A: M.M. Smith i P.C. Heemstra (eds.). Smiths' sea fishes. Springer-Verlag, Berlín. * Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea i W.B. Scott, 1991. World fishes important to North Americans. Exclusive of species from the continental waters of the United States and Canada. Am. Fish. Soc. Spec. Publ. (21):243 p. * Wheeler, A., 1977. Das grosse Buch der Fische. Eugen Ulmer GmbH & Co.

Stuttgart Stuttgart (; ; Swabian German, Swabian: ; Alemannic German, Alemannic: ; Italian language, Italian: ; ) is the capital city, capital and List of cities in Baden-Württemberg by population, largest city of the States of Germany, German state of ...

. 356 p. * Wu, H.L., K.-T. Shao i C.F. Lai (eds.), 1999. Latin-Chinese dictionary of fishes names. The Sueichan Press,