Hexanchiformes
| Hexanchiformes | ||||||||||||
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Collared shark ( Chlamydoselache anguineus ). Drawing from the report of the Challenger expedition , Günther 1887 |
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| Scientific name | ||||||||||||
| Hexanchiformes | ||||||||||||
| Buen , 1926 |
As hexanchiformes a right is called primitive order of sharks , consisting of two families with a total of seven kinds . The animals are sometimes referred to as gray sharks in German. The terms crested sharks and ruffed sharks as common names of the two families of the order are occasionally used for the whole order.
Typical of the sharks of this order is the possession of a single, stingless dorsal fin; In contrast to other orders of the Squalea (e.g. dogfish-like and rays ) they have an anal fin . In contrast to other shark species, which usually have five gill slits , the Hexanchiformes have six or seven.
Systematics
The order is divided into two families:
- The collar sharks (Chlamydoselachidae) in the narrower sense, sometimes also referred to as frilled sharks , include the species Chlamydoselachus anguineus and Chlamydoselachus africana .
- The comb- toothed sharks (Hexanchidae), also called gray sharks, comprise five species in three genera. The term "gray sharks" is not clear and is sometimes also used for the requiem sharks (Carcharhinidae), an unrelated family from the order of the basic sharks (Carcharhiniformes).
Individual evidence
- ^ DA Ebert, LJV Compagno: Chlamydoselachus africana, a new species of frilled shark from southern Africa (Chondrichthyes, Hexanchiformes, Chlamydoselachidae). In: Zootaxa. 2173, 2009, pp. 1-18.
literature
- Joseph S. Nelson : Fishes of the World . John Wiley & Sons, 2006, ISBN 0-471-25031-7 .
- Friedrich H. Pfeil: Dental morphological investigations on recent and fossil sharks of the orders Chlamydoselachiformes and Echinorhiniformes. Self-published, Munich 1983, ISBN 3-923871-00-7 .
