Common sharks
Common sharks | ||||||||||||
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Leopard shark ( Triakis semifasciata ) |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Triakidae | ||||||||||||
Gray , 1851 |
The smooth sharks (Triakidae), also called raccoon sharks or dog sharks , are a family of ground sharks (Carcharhiniformes). They are divided into nine genera and over 45 species , 28 of which belong to the genus Mustelus .
features
They are small to medium-sized (maximum size: two meters) sharks. In contrast to other sharks, the very smooth skin (→ name), which is only covered by tiny skin teeth, is striking. Smooth sharks are usually gray or gray-brown in color, not patterned, with a lighter underside. The head has no laterally protruding edges. The eyes are oval and horizontal. They are usually twice as long as they are tall. There are injection holes but very small. The front nostrils have small flaps that are 2.5 to 3.2 times as wide as the nostrils. The labial folds on the mouth are very long. The teeth are small with 3 to 4 tips. They are in 43 to 60 rows in each jaw and are uniform in both pines. The teeth on the side do not form any comb-like rows. Smooth sharks have two thornless dorsal fins . The first is relatively small and lower than the upper lobe of the caudal fin . It is closer to the base of the pectoral fin than to the base of the pelvic fins . The radials of the pectoral fins are limited to the base of the fin. There are no pits on the tail fin stalk. The upper edge of the upper caudal fin lobe is always smooth. The lower lobe of the caudal fin is small or absent. The vertebral bodies have a wedge-shaped, central, ossified core. The spiral casing has 14 to 16 turns.
Smooth sharks reproduce ovoviviparously or viviparously . The placenta is spherical.
distribution
Great sharks live worldwide in tropical, subtropical and temperate latitudes in the shelf areas of all oceans. Almost no smooth shark lives in the open oceans; it is known that the dog shark can also live pelagically . One species, Iago omanensis , the smallest smooth shark at just 37 centimeters , can be found at depths of 2000 meters. The dog shark ( Galeorhinus galeus ), the gray shark ( Mustelus mustelus ) and the white-spotted shark ( Mustelus asterias ) live in European waters such as the North Sea , the Irish Sea , the English Channel , the Bay of Biscay and the Mediterranean Sea .
Systematics
There are nine genera and 46 species:
- Genus: Furgaleus Whitley, 1951
- Schnauzbarthai ( Furgaleus macki (Whitley, 1943) )
- Genus: Galeorhinus ( Galeorhinus Blainville, 1816 )
- Dog shark ( Galeorhinus galeus (Linnaeus, 1758) )
- Genus: Gogolia ( Gogolia Compagno, 1973 )
- Sailfin-tope ( Gogolia filewoodi Compagno, 1973 )
- Genus: Hemitriakis Herre, 1923
- Deep sea sickle fin dog shark ( Hemitrakis abdita Compagno & Stevens, 1993 )
- Hemitrakis complicofasciata Takahashi & Nakaya, 2004
- Hemitriakis indroyonoi White, Compagno & Dharmadi, 2009
- Sickle fin dog shark ( Hemitrakis falcata Compagno & Stevens, 1993 )
- Japanese dog shark ( Hemitrakis japanica (Müller & Henle, 1839) )
- White-fin dog shark ( Hemitrakis leucoperiptera Herre, 1923 )
- Genus: Hypogaleus Smith, 1957
- Blacktip tope ( Hypogaleus hyugaensis (Miyosi, 1939) )
- Genus: Bigeye dog sharks ( Iago Compagno & Springer, 1971 )
- Long-nosed dog shark ( Iago garricki Fourmanoir & Rivaton, 1979 )
- Bigeye dog shark ( Iago omanensis (Norman, 1939) )
- Genus: Smooth sharks ( Mustelus Linck, 1790 )
- Mustelus albipinnis Castro-Aguirre, Atuna-Mendiola, Gonzáz-Acosta & De la Cruz-Agüero, 2005
- Australian smooth shark ( Mustelus antarcticus Günther, 1870 )
- White-spotted Smooth Shark ( Mustelus asterias Cloquet, 1821 )
- Mustelus californicus Gill, 1864
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Dark Smooth Shark ( Mustelus canis (Mitchill, 1815) )
- Mustelus canis insularis Heemstra, 1997
- Sharp-toothed shark ( Mustelus dorsalis Gill, 1864 )
- Striped smooth shark ( Mustelus fasciatus (Garman, 1913) )
- Spotless smooth shark ( Mustelus griseus Pietschmann, 1908 )
- Brown Smooth Shark ( Mustelus henlei (Gill, 1863) )
- Small-eyed Smooth Shark ( Mustelus higmani Springer & Lowe, 1963 )
- Spotted brackish smooth shark ( Mustelus lenticulatus Phillipps, 1932 )
- Sickfin shark ( Mustelus lunulatus Jordan & Gilbert, 1882 )
- Star- spot smooth shark ( Mustelus manazo Bleeker, 1854 )
- Mustelus mangalorensis Cubelio, Remya & Kurup, 2011
- Spotted Smooth Shark ( Mustelus mento Cope, 1877 )
- Mustelus minicanis Heemstra, 1997
- Arabian smooth shark ( Mustelus mosis Hemprich & Ehrenberg, 1899 )
- Gray shark ( Mustelus mustelus (Linnaeus, 1758) )
- Narrow fin dogfish ( Mustelus norrisi Springer, 1939 )
- White-spotted smooth shark ( Mustelus palumbes Smith, 1957 )
- Black-spotted shark ( Mustelus punctulatus Risso, 1827 )
- Australian smooth shark ( Mustelus ravidus White & Last, 2006 )
- Close-nosed smooth shark ( Mustelus schmitti Springer, 1939 )
- Mustelus sinusmexicanus Heemstra, 1997
- Mustelus stevensi White & Last, 2008
- Mustelus walkeri White & Last, 2008
- Humpback shark ( Mustelus whitneyi Chirichigno F., 1973 )
- White Fin dogfish ( Mustelus widodoi White & Last, 2006 )
- Genus: Scylliogaleus ( Scylliogaleus Boulenger, 1902 )
- Nasal lobe dog shark ( Scylliogaleus quecketti Boulenger, 1902 )
- Genus: Leopard sharks ( Triakis Müller & Henle, 1838 )
- Sharpfin dog shark ( Triakis acutipinna Kato, 1968 )
- Spotted dog shark ( Triakis maculata Kner & Steindachner, 1867 )
- Sharp-toothed dog shark ( Triakis megalopterus (Smith, 1839) )
- Banded dog shark ( Triakis scyllium Müller & Henle, 1839 )
- Leopard shark ( Triakis semifasciata Girard, 1855 )
literature
- Leonard JV Compagno : FAO Species Catalog Vol. 4, Sharks of the World, An Annotated and Illustrated Catalog of Shark Species Known to Date. Part 2 - Carcharhiniformes, page 380, ISBN 92-5-101383-7
- Joseph S. Nelson, Terry C. Grande, Mark VH Wilson: Fishes of the World. John Wiley & Sons, 2016, ISBN 978-1118342336