Houndshark
Leopard Shark ( Triakis semifasciata )
The smooth dogfish ( Triakidae ), also known as raccoon dog sharks or sharks, are a family of ground sharks ( Carcharhiniformes ). They are divided into two subfamilies, nine genera and 39 species, of which 23 belong to the genus Mustelus.
Features
They are small to medium size ( maximum size: two meters) sharks. What is striking is that unlike other sharks very smooth skin (→ name), which is only covered by tiny Hautzähnchen. Smooth dogfish are usually gray or brown colored, not patterned, with a lighter underside. The head has no side protruding edges. The eyes are oval and are horizontal. They are twice as long as usually high. Spray holes are present but very small. The anterior nares have small flaps that are up to 3.2 times as wide as 2.5 the nostrils. The labial to the jaw are very long. The teeth are small with 3-4 spikes. They are available in each jaw in 43-60 rows and are uniform in both jaws. The teeth lying laterally not form comb-like rows. Smooth dogfish have two spineless dorsal fins. The first is relatively small and lower than the upper lobe of the caudal fin. It is closer to the base than pectoral fins to the base of the pelvic fins. The radials of the pectoral fins are restricted to the fin base. Pits on the tail fins handle missing. The upper edge of the upper Schwanzflossenlobus is always smooth. The lower lobe of the caudal fin is small or missing. The vertebral bodies have a wedge-shaped, central ossified core. The spiral intestine has 14 to 16 turns.
Smooth dogfish multiply ovoviviparous or viviparous. The placenta is spherical.
Dissemination
Smooth dogfish live worldwide in tropical, subtropical and temperate latitudes in the shelf areas of all oceans. Almost no dogfish lives in the open seas; from Dogfish is known that he may well live midwater. One type, the smallest with only 37 centimeters dogfish Iago omanensis, goes to depths of 2000 meters. In European waters such as the North Sea, the Irish Sea, the English Channel, the Bay of Biscay and the Mediterranean Sea to the tope shark ( Galeorhinus galeus ), the gray smooth-hound ( Mustelus mustelus ) and the Weißgefleckte dogfish live ( Mustelus asterias ).
System
There are two subfamilies, nine genera and 40 species:
- Subfamily Galeorhininae, small Nasalguben, some with barbels Furgaleus Whitley, 1951 Furgaleus macki ( Whitley, 1943)
- Tope shark ( Galeorhinus galeus ) (Linnaeus, 1758)
- Gogolia filewoodi Compagno, 1973
- Hemitriakis abdita Compagno & Stevens, 1993
- Hemitriakis falcata Compagno & Stevens, 1993
- Hemitriakis Japanica ( Müller & Henle, 1839)
- Hemitriakis leucoperiptera Herre, 1923
- Hypogaleus hyugaensis ( Miyosi, 1939)
- Iago garricki Fourmanoir & Rivaton, 1979
- Iago omanensis (Norman, 1939)
- Mustelus Linck, 1790 Mustelus antarcticus Günther, 1870
- Weißgefleckter smooth dogfish ( Mustelus asterias ) Cloquet, 1821
- Mustelus californicus Gill, 1864
- Mustelus canis ( Mitchill, 1815)
- Mustelus dorsalis Gill, 1864
- Mustelus fasciatus ( Garman, 1913)
- Mustelus griseus Pietschmann, 1908
- Mustelus henlei ( Gill, 1863)
- Mustelus lenticulatus Phillipps, 1932
- Mustelus lunulatus Jordan & Gilbert, 1882
- Mustelus manazo Bleeker, 1854
- Mustelus mento Cope, 1877
- Mustelus canis mini Heemstra, 1997
- Mustelus mosis Klunzinger, 1871
- Gray smooth dogfish ( Mustelus mustelus ) (Linnaeus, 1758)
- Mustelus norrisi Springer, 1939
- Mustelus palumbes Smith, 1957
- Mustelus punctulatus Risso, 1827
- Mustelus schmitti Springer, 1939
- Mustelus sinusmexicanus Heemstra, 1997
- Mustelus whitneyi Chirichigno F., 1973
- Scylliogaleus quecketti Boulenger, 1902
- Triakis acutipinna Kato, 1968
- Triakis maculata Kner & Steindachner, 1867
- Triakis megalopterus (Smith, 1839)
- Triakis Scyllium Müller & Henle, 1839
- Leopard Shark ( Triakis semifasciata ) Girard, 1855