Short-nosed saw shark
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Short-nosed saw shark ( Pristiophorus nudipinnis ) |
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| Pristiophorus nudipinnis | ||||||||||||
| Günther , 1870 |
The short-nosed saw shark ( Pristiophorus nudipinnis ) is a shark from the family of saw sharks (Pristiophoridae). Like its relatives, the shark is characterized by a long saw-like snout, which makes up up to 24% of the body length of this species. He lives off the south coast of Australia .
features
The short-nosed saw shark can reach a length of well over one meter, the previously known maximum length is 124 cm. The body is long, cylindrical and slim. The head is flattened and has a very elongated and flattened snout with a saw-like rostrum typical of saw sharks , which makes up between 22 and 24 percent of the body length of this species. The rostrum has a distinctive pair of barbels in front of the nostrils and 17 to 19 distinctive teeth on the side edge of the "saw". The barbels of this species are close to the nostrils and thus closer to the mouth than to the tip of the saw. There are 12 to 14 teeth in front of the barbels and 6 to 8 behind them. There are also 13 to 14 ventral teeth in front of the barbels and 4 between barbels and nostrils. Young animals also have a small tooth between the larger saw teeth.
The top of its body is a solid gray, the underside white. On the rostrum there are indistinct gray stripes on the center line and along the edges.
The eyes are on the side of the head, behind them the large suction holes . Like other species of the genus, the sawshark has five gill slits . Like all saw sharks, it has two dorsal fins without a thorn and no anal fin . The tail stalk has distinct keels, the tail consists only of a large upper lobe , while the lower lobe is missing in all sawsharks.
Way of life
The short-nosed saw shark is a ground shark that occurs in water depths of up to 70 meters (possibly even deeper up to 165 meters). It feeds on various types of predatory fish , and it also hunts crustaceans , snails and cuttlefish . The long rostrum is used to search for food, which is equipped with barbels and other sensory organs and can therefore perceive movements and probably also electrical fields and chemical impressions in the sea floor. The prey is tracked down with a saw, dug up and probably also partly killed. In addition, the saw shark also uses them against attackers and conspecifics.
The sharks are viviparous and do not form a placenta (aplacentally viviparous ). The females get between seven and 14 young animals with a length of about 25 to 32 cm in one litter. With a body length of about 107 cm, the animals are sexually mature.
distribution
The short-nosed saw shark can be found off the southern coast of Australia from Victoria to Tasmania and New South Wales . Its habitat is in the area of the continental shelf near the sea floor in water depths of up to 70 meters.
Danger
The short-nosed saw shark is classified as not endangered (“least concern”) in the IUCN Red List .
Individual evidence
- ↑ Pristiophorus nudipinnis in the endangered Red List species the IUCN 2016 Posted by: Walker, TI, 2015. Accessed July 29, 2018th
literature
- Leonard Compagno , Marc Dando, Sarah Fowler: Sharks of the World. Princeton Field Guides, Princeton University Press, Princeton and Oxford 2005; P. 133, ISBN 978-0-691-12072-0 .
- Albert Günther: Catalog of the Fishes in the British Museum. Volume Eighth, London 1870, p. 432 ( BHL ).
Web links
- Short-nosed saw shark on Fishbase.org (English)