Goblin shark

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Goblin shark
Mitsukurina.JPG

Kobold Shark ( Mitsukurina owstoni )

Systematics
Sharks (selachii)
Superordinate : Galeomorphii
Order : Mackerel shark (Lamniformes)
Family : Goblin sharks
Genre : Mitsukurina
Type : Goblin shark
Scientific name of the  family
Mitsukurinidae
Jordan , 1898
Scientific name of the  genus
Mitsukurina
Jordan , 1898
Scientific name of the  species
Mitsukurina owstoni
Jordan, 1898

The goblin shark ( Mitsukurina owstoni ) or nose shark is a rare, little-known deep-sea shark , the distribution of which is only known at points. It is the only living ( recent ) species of the Mitsukurinidae family and belongs to the order of the mackerel shark-like (Lamniformes). Fossil finds show that it existed in this form 125 million years ago. The shark reaches an average length of 3 to 4.5 meters and has a pink-tinged gray skin. Its most noticeable feature is its elongated and flattened snout and its jaw, which is equipped with nail-like teeth, which can be stretched out to snap and bite.

features

A photo from 1909 shows goblin sharks described under the synonym Scapanorhynchus jordani . Clearly visible: their outstretched jaws and the long rostrum.
Head of a goblin shark with protruding jaw

Goblin sharks are on average 3 to 4.5 meters long, and one specimen caught in the northern Gulf of Mexico at a depth of around 1,000 meters was even over six meters long. Most of the known specimens were about two meters in length.

They carry a long, paddle-shaped rostrum over their mouth , which is why they are also called nose sharks . Her body is soft, her eyes very small, without a nictitating membrane . The mouth of the goblin shark can be extended very far (protractile), the teeth are long and narrow. The dorsal fins are small and rounded, the caudal fin is long with an underdeveloped lower lobe. The tail fin stalk has no pits or depressions. Kobold sharks have 122 to 125 vertebrae . Like all mackerel shark species, the goblin shark is ovoviviparous .

distribution

Find areas

The goblin shark lives on the outer shelf areas , on the continental slopes and near deep-sea mountains , at depths of 100 to 1,300 meters, mostly between 270 and 960 meters. It has been found in widely scattered, isolated regions in the western ( Gulf of Mexico , Guiana coast ) and eastern Atlantic (France to South Africa), in the southwest Indian Ocean (South Africa), in the western Pacific (Japan, Australia, New Zealand) and eastern Pacific (California ) detected at depths of 30 to 1,350 meters.

Evolution and systematics

Tribal history

Scapanorhynchus lewisii from the chalk of Lebanon .

Fossils of Mitsukurina up to the Eocene back. In addition, the extinct goblin shark genera Anomotodon ( Lower Cretaceous to Eocene) and Scapanorhynchus (Lower Cretaceous to Upper Cretaceous ) have been described. Some scholars believe that Mitsukurina and Scapanorhynchus are congeneric . In this case the name Scapanorhynchus would have priority. Scapanorhynchus had pointed pectoral and dorsal fins and a much longer anal fin than Mitsukurina .

Systematics

The goblin shark was described in 1898 by the American biologist David Starr Jordan as the only species of the genus Mitsukurina also described by him and named in honor of the Japanese zoologist Kakichi Mitsukuri , who brought the holotype caught in the Japanese Sagami Bay to Jordan.

Because of the characteristics that differ from all other known sharks, he also assigned the species and genus to the Mitsukurinidae family, which was also newly described and in which no other recent species have been classified to this day. Among the fossil known species, a total of five genera have been classified in this family: Anomotodon , Protoscapanorhynchus , Pseudoscapanorhynchus , Scapanorhynchus and Woellsteinia . These genera are the closest known relatives of the species.

On the basis of phylogenetic studies, the goblin shark is usually classified as the most pristine species of mackerel sharks (Lamniformes), which include the mako sharks ( Isurus ), the porbeagle sharks ( Lamnia ) and also the great white shark ( Carcharodon carcharias ) as well as the extinct megalodon ( Otodus megalodon ) belong. This basic position has been confirmed by molecular biological studies.

status

Very few animals of this species have been sighted to date, but are scattered over a very wide range in the deep sea of the Atlantic, Pacific and Indian Oceans - with most finds in the northwestern Pacific off the coasts of Japan and Taiwan . The goblin shark is rarely caught by deep-sea fishermen and is of no relevance to fishing. For these reasons and because most of the populations are obviously unknown, it is classified as least concern by the International Union for Conservation of Nature and Natural Resources (IUCN).

supporting documents

  1. ↑ Barton Derek (Ed.): Haie. Big animals of this world. Hamburg 1990, p. 8, ISBN 3-921789-57-5 .
  2. ↑ Shirai, S .: Phylogenetic interrelationships of neoselachians (Chondrichthyes: Euselachii) . In: Stiassny, MLJ; Parenti, LR; Johnson, GD, eds (Ed.): Interrelationships of Fishes . Academic Press, 1996, ISBN 0-08-053492-9 , pp. 9-34.
  3. ↑ Shimada, K .: Phylogeny of lamniform sharks (Chondrichthyes: Elasmobranchii) and the contribution of dental characters to lamniform systematics . In: Paleontological Research . 9, No. 1, 2005, pp. 55-72. doi : 10.2517 / prpsj.9.55 .
  4. ↑ Naylor, GJP; Martin, AP; Mattison, E .; Brown, WM: The inter-relationships of lamniform sharks: testing phylogenetic hypotheses with sequence data . In: Kocher, TD; Stepien, CA, eds (Ed.): Molecular Systematics of Fishes . Academic Press, 1997, ISBN 0-08-053691-3 , pp. 199-218.
  5. ^ Naylor, GJ; Caira, JN; Jensen, K .; Rosana, KA; Straube, N .; Lakner, C .: Elasmobranch phylogeny: A mitochondrial estimate based on 595 species . In: Carrier, JC; Musick, YES; Heithaus, MR, eds (Eds.): The Biology of Sharks and Their Relatives , second. Edition, CRC Press, 2012, ISBN 1-4398-3924-7 , pp. 31-57.
  6. ↑ a b Mitsukurina owstoni in the IUCN Red List of Threatened Species 2013.2. Posted by: CAJ Duffy, CAJ, DA Ebert, C. Stenberg, 2004. Retrieved May 7, 2014.

literature

Web links

Commons : Goblin Shark ( Mitsukurina owstoni )  - Collection of images, videos and audio files