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Hemigaleidae

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The weasel sharks are a family, the Hemigaleidae, of ground sharks found from the eastern Atlantic Ocean to the continental Indo-Pacific. They are found in shallow coastal waters to a depth of 100 m (330 ft).[1]

Most species are small, reaching no more than 1.4 m (4.6 ft) long, though the snaggletooth shark (Hemipristis elongatus) may reach 2.4 m (7.9 ft). They have horizontally oval eyes, small spiracles, and precaudal pits. Two dorsal fins occur with the base of the first placed well forward of the pelvic fins. The caudal fin has a strong ventral lobe and undulations on the dorsal lobe margin. They feed on a variety of small bony fishes and invertebrates; at least two species specialize on cephalopods. They are not known to have attacked people.[2]

Genera and species

The eight known species in this family are placed in four genera. Hemipristis is placed in the subfamily Hemipristinae, while Chaenogaleus, Hemigaleus, and Paragaleus are placed in the subfamily Hemigaleinae.[3]

Chaenogaleus

This genus consists of a single species, the hooktooth shark, characterized by long, hooked teeth in the lower jaw and no toothless spaces at the midlines of the jaws. The gill slits are very long, the snout is wedge-shaped, and the fins are not falchate.[2] Known fossil species include C. affinis.[3]

Hemigaleus

This genus is characterized by a rounded snout and short gill slits. The mouth is short and broadly arched; the teeth have very short cusps, without toothless spaces at the jaw midlines. The dorsal and pelvic fins, and the lower caudal lobe are strongly falchate. At one time or another, this genus has encompassed up to nine species, but most were eventually split off into other genera. Neogaleus Whitley, 1931 is a junior synonym of this genus.[2]

Hemipristis

Main article: Hemipristis

This genus contains a single extant species, the snaggletooth shark. It is distinguished by a rounded snout and very long gill slits. The mouth is long with toothless spaces at the midlines; the lower teeth have very long, strongly hooked cusps and protrude when the mouth is closed. The fins are strongly falchate. Dirrhizodon Kunzinger, 1871 and Heterogaleus Gohar & Mazhar, 1964 are junior synonyms of this genus. Several fossil species are known, including H. curvatus and H. serra; in the Tertiary, this genus had a global distribution.[2][3]

Paragaleus

This genus has a rounded or slightly pointed snout, short gill slits, and a broadly arched mouth. The upper teeth have long cusps, and no toothless spaces occur at the jaw midlines. The dorsal and pelvic fins and the lower caudal lobe are not falchate in shape.[2] Known fossil species include P. pulchellus and P. antunesi.[3]

References

  1. ^ Froese, Rainer, and Daniel Pauly, eds. (2011). "Hemigaleidae" in FishBase. February 2011 version.
  2. ^ a b c d e Compagno, Leonard J. V. (1984) Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agricultural Organization. .mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}ISBN 92-5-101384-5.
  3. ^ a b c d Haaramo, M. (2005). Hemigaleidae - weasel sharks. Mike's Phylogeny Archive. Retrieved on March 3, 2009.
Extant shark species
Hemigaleidae
(Weasel sharks)Hemipristis Chaenogaleus Hemigaleus Paragaleus LeptochariidaeLeptocharias Proscylliidae
(Finback sharks)Ctenacis Eridacnis Proscyllium PseudotriakidaeGollum Pseudotriakis Sphyrnidae
(Hammerhead sharks)Eusphyra Sphyrna Triakidae
(Houndsharks)Furgaleus Galeorhinus Gogolia Hemitriakis Hypogaleus Iago Mustelus
(Smooth-hounds)
Scylliogaleus Triakis Carcharhinidae
  • Large family listed below
Scyliorhinidae
  • Large family listed below
Carcharhinus
Galeocerdo Glyphis
(River sharks) Isogomphodon Lamiopsis Loxodon Nasolamia Negaprion Prionace Rhizoprionodon Scoliodon Triaenodon Apristurus
Asymbolus Atelomycterus Aulohalaelurus Cephaloscyllium Cephalurus Figaro Galeus Halaelurus Haploblepharus Holohalaelurus Parmaturus Pentanchus Poroderma Schroederichthys Scyliorhinus EchinorhinidaeEchinorhinus HeterodontidaeHeterodontus ChlamydoselachidaeChlamydoselachus Hexanchidae
(Cow sharks)Heptranchias Hexanchus Notorynchus AlopiidaeAlopias
(Thresher sharks) CetorhinidaeCetorhinus LamnidaeCarcharodon Isurus Lamna MegachasmidaeMegachasma MitsukurinidaeMitsukurina OdontaspididaeCarcharias Odontaspis PseudocarchariidaePseudocarcharias BrachaeluridaeBrachaelurus Heteroscyllium Ginglymostomatidae
(Nurse sharks)Ginglymostoma Nebrius Pseudoginglymostoma Hemiscylliidae
(Bamboo sharks)Chiloscyllium Hemiscyllium Orectolobidae
(Wobbegongs)Eucrossorhinus Orectolobus Sutorectus Parascylliidae
(Collared carpet sharks)Cirrhoscyllium Parascyllium RhincodontidaeRhincodon StegostomatidaeStegostoma PristiophoridaePliotrema Pristiophorus Centrophoridae
(Gulper sharks)Centrophorus Deania DalatiidaeEuprotomicroides Heteroscymnoides Mollisquama Dalatias Isistius Euprotomicrus Squaliolus EtmopteridaeAculeola Centroscyllium Etmopterus
(Lantern sharks)
Miroscyllium Trigonognathus Oxynotidae
(Rough sharks)Oxynotus Somniosidae
(Sleeper sharks)Centroscymnus Centroselachus Proscymnodon Scymnodalatias Scymnodon Somniosus Zameus Squalidae
(Dogfish sharks)Cirrhigaleus Squalus
(Spurdogs) SquatinidaeSquatina
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Hemigaleidae: Brief Summary

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The weasel sharks are a family, the Hemigaleidae, of ground sharks found from the eastern Atlantic Ocean to the continental Indo-Pacific. They are found in shallow coastal waters to a depth of 100 m (330 ft).

Most species are small, reaching no more than 1.4 m (4.6 ft) long, though the snaggletooth shark (Hemipristis elongatus) may reach 2.4 m (7.9 ft). They have horizontally oval eyes, small spiracles, and precaudal pits. Two dorsal fins occur with the base of the first placed well forward of the pelvic fins. The caudal fin has a strong ventral lobe and undulations on the dorsal lobe margin. They feed on a variety of small bony fishes and invertebrates; at least two species specialize on cephalopods. They are not known to have attacked people.

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Description

provided by World Register of Marine Species
Common coastal tropical sharks from shallow water down to 100 m, limited to the eastern Atlantic and continental Indo-West Pacific but not extending far into the central Pacific. Horizontally oval eyes, small spiracles, two moderate-sized spineless dorsal fins and an anal fin, the first dorsal base well ahead of pelvic bases. Precaudal pits present. Caudal fin with a strong ventral lobe and lateral undulations on its dorsal margin. They feed on small bony fish, small elasmobranchs, cephalopods, crustaceans, and echinoderms.
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bibliographic citation
MASDEA (1997).
i18n: Contributor
Edward Vanden Berghe [email]