Pseudotriakidae

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Pseudotriakidae
Slender Smooth Shark (Gollum attenuatus)

Slender Smooth Shark ( Gollum attenuatus )

Systematics
Subclass : Euselachii
Subclass : Plate gill (Elasmobranchii)
without rank: Sharks (selachii)
Superordinate : Galeomorphii
Order : Ground Sharks (Carcharhiniformes)
Family : Pseudotriakidae
Scientific name
Pseudotriakidae
Gill , 1893

The Pseudotriakidae ( Gr .: pseudes = false + Triakidae = smooth sharks) are a small family of ground sharks (Carcharhiniformes) consisting of only five described , one previously undescribed and one extinct species . There are little-explored deep-water sharks that are found at depths of 129 to 1890 meters on the sea floor, the continental shelf and continental slopes . The largest species, Pseudotriakis microdon , is widespread in all of the world's oceans, while the smaller species in the western Indian Ocean and the western Pacific have very limited ranges. The sharks of the Pseudotriakidae family are absent in the South Atlantic and Eastern Pacific.

features

The species of the family are small to large (56 to 295 cm) and have a rounded head with a more or less elongated rostrum . There is a deep furrow in front of the elongated, cat-like eyes. The nictitating membrane is rudimentary. There are no barbels or nasal pits. The distance between the nostrils is more than 1.5 times the diameter of the nostril. The long, triangular mouth extends behind the rear edge of the eye. There are no protuberances (papillae) in the mouth or on the edges of the gill slits. Labial folds are short but always present.

The first dorsal fin is more or less long. Their base is closer to the pectoral fin base than to the pelvic fin base. Pit-like depressions in front of the caudal fin are missing. The lower lobe of the caudal fin is poorly developed or absent entirely. The Pseudotriakidae are gray, brownish or blackish, with Gollum species white spots and fin edges can appear.

As far as is known, the Pseudotriakidae are oviparous or ovoviviparous . Oophagia was found in two species ; That is, the fetuses feed on food eggs that were only produced as food for the offspring. The sharks likely feed on small fish and invertebrates.

Genera and species

False raccoon shark
( Pseudotriakis microdon )

literature

  • Leonard Compagno , Marc Dando, Sarah Fowler: Sharks of the World. Princeton University Press , Princeton 2005; ISBN 0-691-12072-2 .
  • Ebert, DA, Akhilesh, KV & Weigmann, S. (2018): Planonasus indicus sp. n., a new species of pygmy false catshark (Chondrichthyes: Carcharhiniformes: Pseudotriakidae), with a revised diagnosis of the genus and key to the family. Marine Biodiversity, August 2018.
  • Last, PR & Gaudiano, JP 2011: Gollum suluensis sp. nov. (Carcharhiniformes: Pseudotriakidae), a new gollum-shark from the southern Philippines. Zootaxa , 3002 : 17-30. PDF

Individual evidence

  1. ↑ GR Case. 1978. A new selachian fauna from the Judith River Formation (Campanian) of Montana. Palaeontographica Department A 160 (Lfg. 1–6): 176–205

Web links

Commons : Pseudotriakidae  - collection of images, videos and audio files