Ground sharks
Ground sharks | ||||||||||||
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Blacktip reef shark ( Carcharhinus melanopterus ) |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Carcharhiniformes | ||||||||||||
Compagno , 1977 |
The basic sharks (Carcharhiniformes) are one of the eight orders of the sharks , which in turn can be divided into nine families with 51 genera and around 283 species . Many of the typical shark species such as the great hammerhead shark ( Sphyrna mokarran ), the silk shark ( Carcharhinus falciformis ), tiger shark ( Galeacerdo cuiver ) or the bull shark ( Carcharhinus leucas ) belong to this order.
The distribution area of the bottom sharks are mainly the coastal regions of the tropical to temperate seas. However, the members of the false cat shark family are deep-water forms. There are also species such as the bull shark, which lives in brackish water and can sometimes even be found in fresh water (for example in Lake Nicaragua ). Since the mass extinction at the Cretaceous-Paleogene border , in which the previously dominant order of the mackerel shark-like (Lamniformes) was strongly decimated, the ground sharks have been the dominant shark group in the oceans.
features
All ground sharks have two stingless dorsal fins (only one in Pentachus profundicolus ), an anal fin, five gill slits , the last three of which are above the base of the pectoral fin and a nictitating membrane above the eye. Gill rakes are missing. A spray hole may be present or absent. The inside of the intestine can be leafy or spiral . There are ground sharks that lay eggs such as the narrow-tailed dogfish ( Schroederichthys maculatus ) and viviparous sharks such as the wingtip hammerhead ( Eusphyra blochii ).
Internal systematics of basic sharks according to Naylor et al. (2012) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Systematics
- Cat sharks (Scyliorhinidae) (about 62 species)
- False cat sharks (Proscylliidae) (7 species)
- Smooth sharks (Triakidae) (46 species)
- Pseudotriakidae (about 5 species)
- Slim sharks or Bartel-dogfish (Leptochariidae) (monotypic)
- Weasel Sharks (Hemigaleidae) (8 species)
- Requiem sharks (Carcharhinidae) (about 59 species)
- Hammerhead Sharks (Sphyrnidae) (9 species)
- Pentanchidae (over 90 species)
As the cladogram shows, the cat sharks and the false cat sharks are probably paraphyletic .
literature
- LJV Compagno: Sharks of the world. An annotated and illustrated catalog of shark species known to date. Part 2. Carcharhiniformes. FAO Species Catalog for Fishery Purposes Vol. 4. FAO Rome 1984 ( fao.org Full PDF).
Web links
- Ground sharks on Fishbase.org (English)
- hai.ch: Information about ground sharks
Individual evidence
- ↑ Nicolás E. Campione, Per E. Ahlberg, Henning Blom, Benjamin P. Kear, Mohamad Bazzi: Static Dental Disparity and Morphological Turnover in Sharks across the End-Cretaceous Mass Extinction . In: Current Biology . tape 28 , no. 16 , 2018, ISSN 0960-9822 , p. 2607–2615.e3 , doi : 10.1016 / j.cub.2018.05.093 , PMID 30078565 .
- ↑ Gavin JP Naylor, Janine N. Caira, Kirsten Jensen, Kerri AM Rosana, Nicolas Straube, Clemens Lakner: Elasmobranch Phylogeny: A Mitochondrial Estimate Based on 595 Species. Pp. 39 to 40 in Jeffrey C. Carrier, John A. Musick, Michael R. Heithaus: Biology of Sharks and Their Relatives (Marine Biology). Publisher: Crc Pr Inc, 2012, ISBN 1-43983-924-7 .
- ^ A b Samuel P. Iglésias, Guillaume Lecointre, Daniel Y. Sellos: Extensive paraphylies within sharks of the order Carcharhiniformes inferred from nuclear and mitochondrial genes. In: Molecular Phylogenetics and Evolution. 34, 2005, pp. 569-583 ( mnhn.fr PDF).