Natal dogfish

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Natal dogfish
Systematics
without rank: Sharks (selachii)
Superordinate : Galeomorphii
Order : Ground Sharks (Carcharhiniformes)
Family : Cat sharks (Scyliorhinidae)
Genre : Shy sharks ( Haploblepharus )
Type : Natal dogfish
Scientific name
Haploblepharus kistnasamyi
Human & Compagno , 2006

The Natal dogfish ( Haploblepharus kistnasamyi ), also Eastern Scheuhai or "Happy Chappie", is a kind from the family of dogfish (Scyliorhinidae), which is endemic in the waters off the coast of South Africa alive. Until it was first described scientifically in 2006, this species was regarded as the natal form of the puff adder cat shark ( H. edwardsii ).

The Natal dogfish lives near the seabed ( benthic ) in the area of ​​the coast to a depth of about 30 meters. It reaches an average body length of around 50 centimeters and largely corresponds to the puff adder dogfish in its appearance, but is somewhat more stocky with a less flattened head and a slightly different body pattern.

features

The Natal dogfish reaches a body length of about 50 centimeters and is morphologically very similar to the puff adder dogfish, but has a more compact body, a less flattened head and a laterally flattened tail stem. The back is brown with a characteristic drawing of H-shaped, dark brown saddle spots with clearly defined outer edges as well as numerous small white spots and a darker marbling between the saddle spots. The belly is white.

The muzzle is broad and rounded. The large, oval, rounded eyes have cat-like slit pupils , a simple nictitating membrane and a prominent elevation below the eye. The nostrils are very large and in front each have a pair of greatly enlarged, triangular skin flaps that have grown together and extend to the mouth. A deep pit connects the outflow opening of the nostrils with the mouth, covered by the nasal lobes. The mouth opening is short and has furrows in the corners of the mouth. The five pairs of gill slits are shifted to the top of the body.

The dorsal, ventral and anal fins are roughly the same size. The dorsal fins start very far back on the body, with the first dorsal fin beginning behind the attachment of the ventral fin and the second dorsal fin behind the anal fin. The pectoral fins are broad and medium-sized. The short and broad caudal fin is about one-fifth the length of the body and has a deep notch near the tip of the upper lobe and a barely developed lower lobe. The skin is thick and covered by heavily calcified, leaf-shaped placoid scales.

distribution and habitat

Distribution area of ​​the Natal cat shark

The distribution area of ​​the Natal cat shark is limited to the coastal region in the Western Cape , Eastern Cape and KwaZulu-Natal provinces in South Africa .

The bottom-living shark occurs mainly in areas with stony to rocky bottom and in shallow water reefs . In contrast to the puff adder dogfish, which mainly lives in somewhat deeper, cooler water areas in the northeastern part of its range, the natal dogfish prefers the warmer water zones at depths of 0 to 30 meters.

Way of life

The way of life of the Natal cat shark largely corresponds to that of other species of its genus. It is less common than the puff adder dogfish.

The males reach sexual maturity with a body length of about 50 centimeters, the females with about 48 centimeters. When threatened or disturbed, the Natal dogfish, like the other shy sharks, assumes a characteristic position in which it curls up and covers its eyes with its tail. It is believed that this way the shark is more difficult to swallow for a potential attacker.

Systematics

The Natal dogfish was originally considered the natal form of the puff adder dogfish ( H. edwardsii ) in addition to the cape form due to the different choice of habitat and appearance . In 2006, the natal form was newly described by Brett A. Human and Leonard JV Compagno as a separate species H. kistnasamyi and thus raised to species status. The species was named after the South African shark researcher Nat Kistnasamy , who originally discovered the Natal dogfish .

A molecular biological investigation based on three genes of the mitochondrial DNA revealed that the puff adder dogfish is the most original species of its genus. The dark dogfish ( H. pictus ) and the brown dogfish ( H. fuscus ) are sister species according to this study; the natal dogfish was not considered in this study.

supporting documents

  1. ↑ a b c d e f Compagno, LJV, M. Dando and S. Fowler: Sharks of the World . Princeton University Press, 2005, ISBN 9780691120720 , pp. 234-235.
  2. ^ A b Human, BA and Compagno, LJV: Description of Haploblepharus kistnasamyi , a new catshark (Chondrichthyes: Scyliorhinidae) from South Africa . In: Zootaxa . 1318, 2006, pp. 41-58.
  3. ↑ a b c Compagno, LJV: Sharks of the World: An Annotated and Illustrated Catalog of Shark Species Known to Date . Food and Agricultural Organization, Rome 1984, ISBN 9251013845 , pp. 332-333.
  4. ↑ Human, BA: A taxonomic revision of the catshark genus Haploblepharus Garman 1913 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) . In: Zootaxa . 1451, 2007, pp. 1-40. ( PDF )
  5. ^ UCT Scientists Honor Shark Researcher. January 18, 2009, archived from the original on September 20, 2009 ; Retrieved July 19, 2013 .
  6. ↑ Human, BA, EP Owen, LJV Compagno and EH Harley: Testing morphologically based phylogenetic theories within the cartilaginous fishes with molecular data, with special reference to the catshark family (Chondrichthyes; Scyliorhinidae) and the interrelationships within them . In: Molecular Phylogenetics and Evolution . 39, No. 2, May 2006, pp. 384-391. doi : 10.1016 / j.ympev.2005.09.009 . PMID 16293425 .

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