''Hemiscyllium'' is a genus of sharks in the family Hemiscylliidae.

Overview

Hemiscyllium sharks of the family Hemiscylliidae are also known as walking sharks and Epaulette sharks. These small, nocturnal, benthic dwelling swimmers have evolved to be able to 'walk', or use their fins to propel themselves over rocks, into pools, or into small crevices in their habitats. Research from the School of Biomedical Sciences at the

University of Queensland The University of Queensland is a Public university, public research university located primarily in Brisbane, the capital city of the Australian state of Queensland. Founded in 1909 by the Queensland parliament, UQ is one of the six sandstone ...

in Australia has determined that this genus most recently split from the genus Chiloscyllium around 44 million years ago. This genus is confined to tropical waters off

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

, and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

, but an individual from this genus, possibly representing an undescribed species, has been photographed in the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (; Seychellois Creole: ), is an island country and archipelagic state consisting of 155 islands (as per the Constitution) in the Indian Ocean. Its capital and largest city, Victoria, ...

.Debelius, H. (1993). ''Indian Ocean Tropical Fish Guide.'' Aquaprint Verlags GmbH. They have short snouts with

nostrils A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates, ...

placed almost at the tip, well-elevated eyes, and supraorbital ridges. The mouth is closer to the tip of the snout than the eyes and lacks the connecting dermal fold across the chin. The pectoral and pelvic fins are thick and heavily muscular. Either a black hood on the head or a large black spot on the sides of the body is present, though juveniles often are strongly marked with dark spots/bars. This shark family can survive around two hours out of water without any internal damage, can tolerate high levels of CO₂, and are hypoxia and anoxia tolerant.

Adaptations

Epaulette sharks live in shallow waters near reefs, tidepools or islands and are currently only found in the Western South Pacific. Epaulette sharks use their fins to crawl inside small crevices or holes while hunting for small prey and escaping larger predators. Each species in this genus also possesses a distinct black 'eye' spot behind its pectoral fins to deter predators by giving the appearance of a very large eye. Neonate and juvenile epaulette sharks are born with lighter color markings and slightly different patterns, but their colors darken as they mature, with patterns shifting to mimic its environment.

List of species

Nine recognized species are in this genus: * '' Hemiscyllium freycineti'' ( Quoy &

Gaimard Joseph Paul Gaimard (31 January 1793 – 10 December 1858) was a French naval surgeon and naturalist. Biography Gaimard was born at Saint-Zacharie on January 31, 1793. He studied medicine at the naval medical school in Toulon, subsequent ...

, 1824) (Indonesian speckled carpetshark) * '' Hemiscyllium galei'' G. R. Allen & Erdmann, 2008 (Cenderwasih epaulette shark) * ''

Hemiscyllium hallstromi The Papuan epaulette shark, ''Hemiscyllium hallstromi'', is a bamboo shark in the family (biology), family Hemiscylliidae found around southern Papua New Guinea, between latitudes 7th parallel south, 7° S and 10th parallel south, 10° S, and lo ...

'' Whitley, 1967 (Papuan epaulette shark) * '' Hemiscyllium halmahera'' G. R. Allen, Erdmann &

Dudgeon Dudgeon is a surname. Notable people with the surname include: * Cecil Dudgeon, politician * Gus Dudgeon Angus Boyd "Gus" Dudgeon (30 September 1942 – 21 July 2002) was an English record producer, who oversaw many of Elton John's most accla ...

, 2013 (Halmahera epaulette shark) * '' Hemiscyllium henryi'' G. R. Allen & Erdmann, 2008 (Henry's epaulette shark) * '' Hemiscyllium michaeli'' G. R. Allen &

, 2010 (Milne Bay epaulette shark) * '' Hemiscyllium ocellatum'' ( Bonnaterre, 1788) (epaulette shark) * '' Hemiscyllium strahani'' Whitley, 1967 (hooded carpetshark) * '' Hemiscyllium trispeculare'' J. Richardson, 1843 (speckled carpetshark) * '' Hemiscyllium sp.'' Not yet described (Seychelles carpetshark)

References

{{Taxonbar, from=Q557963 Shark genera Taxa named by Johannes Peter Müller Taxa named by Friedrich Gustav Jakob Henle Walking fish