The weasel sharks are a family, the Hemigaleidae, of ground sharks found from the eastern
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
to the continental
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 ...
. They are found in shallow coastal waters to a depth of .
Most species are small, reaching no more than long, though the
snaggletooth shark
The snaggletooth shark, or fossil shark (''Hemipristis elongata''), is a species of weasel shark in the family Hemigaleidae, and the only extant member of the genus ''Hemipristis''. It is found in the Indo-West Pacific, including the Red Sea, fro ...
(''Hemipristis elongatus'') may reach . They have horizontally oval eyes, small
spiracle Spiracle or spiraculum may refer to:
* Spiracle (arthropods), opening in the exoskeletons of some arthropods
* Spiracle (vertebrates), openings on the surface of some vertebrates
* Spiraculum, a genus of land snails in family Cyclophoridae
Cycl ...
s, and precaudal pits. Two
dorsal fin
A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...
s occur with the base of the first placed well forward of the
pelvic fin
Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods.
Structure and function Structure
In actinopterygians, the pelvic fin consists of two en ...
s. The
caudal fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...
has a strong ventral lobe and undulations on the dorsal lobe margin. They feed on a variety of small
bony fish
Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...
es and
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s; at least two species specialize on
cephalopod
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...
s. They are not known to have attacked people.
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.Haaramo, M. (2005) Hemigaleidae - weasel sharks ''Mike's Phylogeny Archive''. Retrieved on March 3, 2009.
''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 slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In con ...
s are very long, the
snout
A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is c ...
is wedge-shaped, and the fins are not falcate.Compagno, Leonard J. V. (1984) ''Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date''.
Rome
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, established_date = 753 BC
, founder = King Romulus (legendary)
, image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg
, map_caption ...
:
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
. . Known fossil species include '' C. affinis''.
* ''
Chaenogaleus macrostoma
The hooktooth shark (''Chaenogaleus macrostoma''), is a weasel shark of the family Hemigaleidae, the only extant member of the genus ''Chaenogaleus'', but there is an extinct species, ''Chaenogaleus affinis''. The hooktooth shark is found in th ...
'' (
Bleeker Bleeker is a Dutch occupational surname. Bleeker is an old spelling of ''(linnen)bleker'' ("linen bleacher").
''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
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently.
* In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...
of this genus.
* ''
Hemigaleus australiensis
The Australian weasel shark (''Hemigaleus australiensis'') is an uncommon species of Carcharhiniformes, ground shark in the family (biology), family Hemigaleidae. It inhabits shallow waters off northern Australia to a depth of ; smaller sharks fr ...
''
W. T. White W. may refer to:
* SoHo (Australian TV channel) (previously W.), an Australian pay television channel
* ''W.'' (film), a 2008 American biographical drama film based on the life of George W. Bush
* "W.", the fifth track from Codeine's 1992 EP ''Bar ...
,
Last
A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts typically come in pairs and have been made from various materials, including hardwoods, cast iron, and ...
snaggletooth shark
The snaggletooth shark, or fossil shark (''Hemipristis elongata''), is a species of weasel shark in the family Hemigaleidae, and the only extant member of the genus ''Hemipristis''. It is found in the Indo-West Pacific, including the Red Sea, fro ...
. 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
Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago.
The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...
, this genus had a global distribution.
* ''
Hemipristis elongata
The snaggletooth shark, or fossil shark (''Hemipristis elongata''), is a species of weasel shark in the family Hemigaleidae, and the only extant member of the genus ''Hemipristis''. It is found in the Indo-West Pacific, including the Red Sea, fro ...
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. Known fossil species include '' P. pulchellus'' and '' P. antunesi''.
* '' Paragaleus leucolomatus'' Compagno &
Smale Smale is a surname. Notable people with the surname include:
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* John G. Smale (1927-2011), American businessman
*Sir John Jackson Smale, British lawyer and Chief Justice of Hong Kong
* Step ...
Garman Garman is a surname or first name. Notable people with the name include:
Sports
* Ann Garman, All-American Girls Professional Baseball League player
* Judi Garman (born 1954), American softball coach
* Mike Garman (born 1949), American baseball pla ...
Krupp
The Krupp family (see pronunciation), a prominent 400-year-old German dynasty from Essen, is notable for its production of steel, artillery, ammunition and other armaments. The family business, known as Friedrich Krupp AG (Friedrich Krup ...
Paragaleus tengi
The straight-tooth weasel shark, ''Paragaleus tengi'', is a Carcharhiniformes, weasel shark of the family (biology), family Hemigaleidae, found in the tropical western Pacific Ocean. It can reach a length of 88 cm.
''Paragaleus tengi'' is ...