Japanese sea sow

Japanese sea sow
Systematics
without rank:	Sharks (selachii)
Superordinate :	Squalomorphii
Order :	Spiny dogfish (Squaliformes)
Family :	Pig sharks (Oxynotidae)
Genre :	Pig sharks ( Oxynotus )
Type :	Japanese sea sow
Scientific name
	Oxynotus japonicus
	Yano & Murofushi , 1985

The Japanese sea sow ( Oxynotus japonicus ) is a species of the pig sharks (Oxynotidae) within the dogfish-like (Squaliformes).

features

The Japanese sea sow is only known from a few specimens so far. The maximum length of the seven individuals described was 64.5 centimeters. Like all species of the family, it has a very high-backed body with a triangular cross-section, so that there are lateral keels between the pectoral and pelvic fins. The color of the sharks is uniformly dark brown and without any pattern. The lips, the edges of the nasal valves, the base of the fins and the inner edges of the clasps are white.

The muzzle is short and blunt. The two dorsal fins are very high and sail-like with a triangular tip and concave back; the spine in front of the first dorsal fin points forward. One anal fin is missing. In front of the gills there is a small and edgewise oval injection hole with a length of less than half the diameter of the eye.

distribution and habitat

Distribution area of the Japanese sea sow.

The Japanese sea sow has only been found in Suruga Bay on the Japanese island of Honshū in the western Pacific .

The shark lives above the area of the continental shelf at a depth of around 150 to 350 meters.

Way of life

There is no information about the way of life of this species. The shark likely feeds on bottom-dwelling invertebrates and smaller fish. The high-backed shape represents an adaptation to the sharks' way of life near the ground.

Like other species of the genus , it is probably viviparous ( ovoviviparous ), but does not form a yolk sac placenta .

Hazard and protection

The Japanese Meersau is fished commercially not targeted, but, like other sharks as bycatch in the trawl fishery caught. Concrete catch data are not available for this species, so far only seven individual animals have been described. Due to the few available data, the shark is known as "data deficient" in the endangered Red List species the IUCN classified, however, a risk assessment is assumed for the future because of the very limited distribution area and the existing fishing pressure.

supporting documents

↑ ^a ^b ^c ^d Oxynotus caribbaeus in the endangered Red List species the IUCN 2011. Posted by: K. Yano, 2004. Accessed December 30, 2011th
^ ^A ^b ^c ^d Leonard Compagno, Marc Dando, Sarah Fowler: Sharks of the World . Princeton University Press, Princeton and Oxford 2005, ISBN 978-0-691-12072-0 , pp. 122-123.
↑ Prickly Dogfish, Oxynotus bruniensis (Ogilby, 1893) Australien Museum, accessed on March 20, 2011. There related to Oxynotus bruniensis , but directly transferable to other species.

literature

Leonard Compagno , Marc Dando, Sarah Fowler: Sharks of the World . Princeton University Press , Princeton and Oxford 2005, ISBN 978-0-691-12072-0 , p. 124.

Web links

Japanese sea sow on Fishbase.org (English)

[IUCN-1] Oxynotus caribbaeus in the endangered Red List species the IUCN 2011. Posted by: K. Yano, 2004. Accessed December 30, 2011th

[Compagno-2] A ^b ^c ^d Leonard Compagno, Marc Dando, Sarah Fowler: Sharks of the World . Princeton University Press, Princeton and Oxford 2005, ISBN 978-0-691-12072-0 , pp. 122-123.

[Australian_Museum-3] Prickly Dogfish, Oxynotus bruniensis (Ogilby, 1893) Australien Museum, accessed on March 20, 2011. There related to Oxynotus bruniensis , but directly transferable to other species.