Haploblepharus

Puffotter catshark (H. edwardsii )

The fear sharks ( Haploblepharus ) are a genus of the shark family of Pentanchidae with four species. Your common name is derived from their behavior, to curl up with a potential threat and to cover the eyes with the tail. The genus is endemic in the sea area off the coast of South Africa where they live in shallow waters of the coastal area. All four species are small and have a stocky body with a broad, flattened head and a rounded snout. Characteristic are very large nostrils with enlarged, triangular flaps of skin that extend to the mouth.

Fear sharks are bottom dwelling hunters, from invertebrates (crustaceans, marine worms) and small bony fish feed. They are oviparous, where the females lay large egg capsules. Due to their size the harmless to humans sharks by fishermen are not generally used and discarded as bycatch.

Features

The types of shyness sharks are very similar in appearance, but may be safely distinguished on the basis of morphological features. In their habitat, however, is their different coloration and patterning the only way to distinguish them from each other. However, this can vary, sometimes significantly within species, creating a free- determination is problematic. All four species are very small and are rarely longer than about 60 inches.

Fear sharks have an upset, spindle-shaped body with a short head, which accounts for less than one fifth of the total length. The ground color of the back is brown and the animals have artabhängig a drawing from darker saddles and a white dotting. The belly is white. The head is flattened dorsally and wide, the muzzle is rounded. The large, oval-shaped eyes feline slitted pupils, a rudimentary trained nictitating membrane and a prominent increase below the eye. The nostrils are very large and have the front each have a pair of typical genre and greatly enlarged, triangular flaps of skin that have grown together and extend to the mouth. One of them hidden deep pit connects the orifice of the nostrils with the mouth hidden by the Nasallappen. The mouth is short and curved and has furrows in the mouth. The teeth have a central tooth tip and smaller subsidiary peaks. The five pairs of gill slits are shifted to the body top.

The two dorsal fins set far back on the body, the first dorsal fin starts behind the approach of the ventral fin and the second dorsal fin behind the anal fin. The pectoral fins are large and medium size designed the dorsal, ventral and anal fins are about the same size. The short and wide tail comprises about one-fifth of the body length and has a deep notch near the tip of the upper lobe and a barely developed lower lobe. The skin is thick and covered with highly calcified, leaf -shaped placoid scales.

Distribution and habitat

All four types of fear sharks are endemic to the coastal waters of the southern tip of the African continent. Three species live exclusively in the coastal area of South Africa, during the Dark dogfish is also to be found in the area of ​​southern Namibia.

The sharks are ground alive and are mainly found in shallow coastal waters over sandy and stony ground.

Way of life

Fear sharks feed as generalist hunters from a variety of invertebrates, particularly crustaceans and marine worms and small bony fishes. They themselves are captured mainly by larger fish and marine mammals, especially seals. When threatened, the sharks roll their bodies together to form a ring and cover the eyes with the tail. It is believed that the sharks are thus difficult to swallow for a potential attacker.

Fear sharks are oviparous ( oviparous ) and the females lay the eggs usually in pairs in the form of egg capsules with long mounting threads. Reproduction takes place throughout the year and there is no definable breeding season.

Evolution and systematics

The genus Haploblepharus 1913 by the American zoologist Samuel Garman in the 36th edition of the Memoirs of the Museum of Comparative Zoology, at Harvard College for receiving the puff adder - dogfish ( Squalus hitherto described as edwardsii ) was established. The name derives from the Greek terms haplóos for " single " and blepharos for " eyelid " from.

In 1988, the fear of sharks Leonard Compagno on the basis of morphological features in common with the Izak cat sharks ( Holohalaelurus ) and the Tiger - Cats sharks ( Halaelurus ) in the tribes Halaelurini within the family of dogfish ( Scyliorhinidae ) were classified. In 2005 she was assigned along with eight other genera of the family Pentanchidae revalidated.

Izak - dogfish ( Holohalaelurus )

Fear sharks ( Haploblepharus )

Tiger dogfish ( Halaelurus )

Overall, the genus of fear sharks includes four described species:

• Puffotter catshark ( Haploblepharus edwardsii ( Schinz, 1822) )
• Brown dogfish ( Haploblepharus fuscus Smith, 1950)
• Natal catshark ( Haploblepharus kistnasamyi Human & Compagno, 2006)
• Dark dogfish ( Haploblepharus pictus ( Müller & Henle, 1838) )

The Natal catshark ( Haploblepharus kistnasamyi ) was originally considered as a local form of the puff adder, dogfish and described in 2006 as a separate species. Through a molecular investigation on the basis of three genes of mitochondrial DNA was determined that the puff adder catshark is the primary mode of its kind. The Dark dogfish (H. pictus) and the brown catshark ( H. fuscus ) represent after this examination sister species, the Natal catshark was not considered in this study.

Puffotter catshark (H. edwardsii ) and Natal catshark (H. kistnasamyi )

Dark dogfish (H. pictus)

Brown dogfish (H. fuscus )

Relationship to man

The types of shyness sharks are harmless to humans.

Due to their small size, the sharks are for commercial fishing of no interest, but are caught and discarded by bottom trawl fishermen and fishermen in the area of ​​False Bay as by-catch. In addition, many of the sharks are caught by anglers from the shore and also killed and disposed of. Local can be used as bait for lobster and caught as aquarium fish sharks. The International Union for Conservation of Nature ( IUCN) classifies two types of fear sharks as a species near threatened a ( Near Threatened ), as they are indeed numerous within their range, this however is very small and located in a heavily fished area and thereby a increase in fishing or a decline of habitats could potentially have a strong effect on the overall populations.