Haploblepharus

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Haploblepharus
Puffadder shyshark (H. edwardsii)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Carcharhiniformes
Family: Scyliorhinidae
Genus: Haploblepharus
Garman, 1913
Type species
Squalus edwardsii
Schinz 1822

Haploblepharus is a

egg capsules. These harmless sharks are of no commercial or recreational
interest, though their highly limited distributions in heavily fished South African waters are of potential conservation concern.

Taxonomy and phylogeny

The genus Haploblepharus was created by American zoologist Samuel Garman in 1913, in the 36th volume of Memoirs of the Museum of Comparative Zoology, at Harvard College, to contain the puffadder shyshark, then known as Squalus edwardsii.[1] The name is derived from the Greek haplóos meaning "single", and blepharos meaning "eyelid".[2]

In 1988,

phylogenetic analysis based on three mitochondrial DNA genes. However, that study also found that within this group Haploblepharus is most closely related to the genus Halaelurus, which is inconsistent with the presence of three autapomorphic traits in Haploblepharus that are not shared by either Halaelurus or Holohalaelurus. Within the genus, the puffadder shyshark is the most basal species.[3]

Species

Distribution and habitat

All four shyshark species are

bottom-dwelling in nature and usually found in shallow, coastal waters over sandy or rocky bottoms.[1]

Description

The broad, flattened head of a dark shyshark

Different shyshark species are very similar to one another in appearance but can be reliably differentiated using morphological measurements. However, in the field the only way to readily tell them apart is by their different color patterns, and even this may be problematic as individuals of the same species can vary considerably in coloration.[4] All four species are small, seldom exceeding 60 cm (24 in) in length.[5]

A shyshark has a stout, spindle-shaped body and a short head comprising less than one-fifth of the total length. The head is broad and dorsally flattened, with a rounded snout. The large, oval eyes have cat-like slit pupils, a rudimentary nictitating membrane (protective third eyelid), and a prominent ridge running underneath. A distinguishing trait of this genus are the large nostrils partially covered by greatly expanded, triangular flaps of skin that overlap the mouth and cover a pair of deep grooves between the nasal excurrent (outflow) openings and the mouth. The mouth is short and curved, with furrows at the corners extending onto both jaws. The teeth have a central cusp and smaller lateral cusplets. The five pairs of gill slits are located on the upper side of the body.[1]

The two

dermal denticles. The coloration is brown above and white below; the brown shyshark is usually plain while the other species have varying patterns of darker "saddles" and white spots.[1]

Biology and ecology

The egg case of a puffadder shyshark

Shysharks feed on a variety of small benthic

breeding season, and their eggs take around three and a half weeks to hatch.[6]

Human interactions

Due to their small size, shysharks pose no danger to humans and are not sought by either

Near Threatened.[7]

References

  1. ^
    ISBN 92-5-101384-5
    .
  2. ^ Bester, C. Biological Profiles: Puffadder Shyshark. Florida Museum of Natural History Ichthyology Department. Retrieved on August 31, 2009.
  3. PMID 16293425
    .
  4. ^ Human, B.A. (2007). "Size-corrected shape variation analysis and quantitative species discrimination in a morphologically conservative catshark genus, Haploblepharus Garman, 1913 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)". African Natural History. 3: 59–73.
  5. ISBN 1-86872-890-0
    .
  6. ^ Dainty, A.M. (2002). Biology and ecology of four catshark species in the southwestern Cape, South Africa. M.Sc. thesis, University of Cape Town.
  7. ISBN 2-8317-0700-5
    .
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