Bramble shark

This is a good article. Click here for more information.
Source: Wikipedia, the free encyclopedia.

Bramble shark
Echinorhinus brucus, illustration of the zoology of South Africa (1838)
Echinorhinus brucus, mounted specimen.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Squaliformes
Family: Echinorhinidae
Genus: Echinorhinus
Species:
E. brucus
Binomial name
Echinorhinus brucus
(Bonnaterre, 1788)
Range of the bramble shark[2]
Synonyms

Echinorhinus mccoyi Whitley, 1931
Echinorhinus obesus Smith, 1838
Squalus brucus Bonnaterre, 1788
Squalus spinosus Gmelin, 1789

The bramble shark (Echinorhinus brucus) is one of the two

dermal denticles
scattered over its body, some of which may be fused together. It is purplish brown or black in color and grows up to 3.1 m (10 ft) long.

The diet of the bramble shark includes smaller sharks,

fishmeal and liver oil. Its population has declined substantially in the northeastern Atlantic since the 18th and 19th centuries, likely because of overfishing
.

Taxonomy

The original description of the bramble shark was authored by French

type specimen has since been lost.[5] In 1816, Henri de Blainville created the genus Echinorhinus for this species.[6] Until the 1960s, specimens of the prickly shark (E. cookei) caught in the Pacific Ocean were misidentified as bramble sharks.[4] Other common names for this species are spinous shark and spiny shark.[7]

Description

Distinctive traits of the bramble shark include its posteriorly placed dorsal fins, lack of an anal fin, and large thorn-like dermal denticles (detail below).
Jaws, lower and upper teeth

The bramble shark has a thick, cylindrical body and a somewhat flattened head. The snout is blunt and shorter than the width of the mouth, with widely spaced nostrils that are preceded by small flaps of skin. The eyes lack nictitating membranes; the tiny spiracles are located well behind them. The wide, curved mouth bears very short furrows at the corners. There are 20–26 upper and 22–26 lower tooth rows; each tooth is knife-like, with a single main cusp and up to three cusplets on either side. There are five pairs of gill slits, with the fifth pair the longest.[5][8]

The

caudal fin origins. The asymmetrical caudal fin has an indistinct lower lobe and an upper lobe without a notch in the trailing margin.[9]

The skin is covered by a layer of foul-smelling

dermal denticles are scattered irregularly over the body and vary greatly in size, measuring up to 1.5 cm (0.59 in) across. Each denticle is thorn-like in shape, with ridges radiating out from the central point over the base. As many as ten denticles may be fused together to form multi-pointed plates. The underside of the snout and the area around the mouth is densely covered by small denticles in sharks under 90 cm (35 in) long; these denticles become larger and sparser in larger sharks. This species is brown to black above, with a metallic purplish hue, and paler below; some individuals have red or black blotches. There is a report of one specimen that had a greenish glow when freshly caught. The bramble shark may reach 3.1 m (10 ft) in length. The maximum weight on record is 200 kg (440 lb) for a 2.8 m (9.2 ft) long female.[2][4][5]

Distribution and habitat

Records of the bramble shark are fairly rare and originate from widely scattered locations in

Atlantic and western Indian Oceans, where its range extends from the North Sea and the British Isles to southern Mozambique, including the Mediterranean Sea. In the western Atlantic, this species is represented by a handful of specimens from Massachusetts, North Carolina, Louisiana, Tobago, Brazil, and Argentina.[4] In the Indo-Pacific, it is known from Oman,[12] India, southern Japan, southern Australia, New Zealand, and possibly Kiribati.[5]

Found close to the

slopes at depths of 400–900 m (1,300–3,000 ft).[13] However, it has been reported from as shallow as 18 m (59 ft), in areas with upwellings of cold water, and from as deep as 1,214 m (3,983 ft).[2][5][9] At least in European waters, this species may migrate into shallower depths of 20–200 m (66–656 ft) during the summer.[4]

Biology and ecology

The spiny dogfish (pictured) is a known prey item of the bramble shark.
Bramble shark embryo with external yolk sac.

Sluggish in nature, the bramble shark feeds on smaller sharks (including the

aplacental viviparous; females have two functional ovaries and two uteruses. Recorded litter sizes have ranged from 15 to 52, and newly born pups have been estimated to measure 40–50 cm (16–20 in) long.[4][14] The dermal denticles in near-term embryos are underdeveloped, appearing as minute spines located within open pits in the skin.[15] The size at sexual maturity is uncertain; the smallest known mature males and females are 1.5 m (4.9 ft) and 2.1 m (6.9 ft) long respectively.[5]

Human interactions

The bramble shark is not known to pose a danger to humans. It is

lifespans.[4][9] Regarding the species as a whole, the International Union for Conservation of Nature (IUCN) assesses it as Endangered.[1] In June 2018 the New Zealand Department of Conservation classified the bramble shark as "At Risk – Naturally Uncommon" with the qualifiers "Data Poor" and "Secure Overseas" under the New Zealand Threat Classification System.[16]

References

  1. ^
    doi:10.2305/IUCN.UK.2020-3.RLTS.T41801A2956075.en
    . Retrieved 19 November 2021.
  2. ^
    ISBN 978-0-691-12072-0
    .
  3. ^ Bonnaterre, J.P. (1788). Tableau encyclopédique et methodique des trois règnes de la nature... Ichthyologie. Panckoucke. p. 11.
  4. ^
    ISBN 978-0-19-539294-4
    .
  5. ^
    ISBN 92-5-101384-5
    .
  6. ^ Blainville, H. de (1816). "Prodrome d'une nouvelle distribution systématique du règne animal". Bulletin de la Société Philomathique de Paris. 8: 105–112.
  7. ^ a b Froese, R.; Pauly, D. (eds). "Echinorhinus brucus". FishBase. March 2012 Version. Downloaded on March 24, 2012.
  8. ISBN 978-0-292-75206-1
    .
  9. ^ a b c Kabasakal, H.; Oz, M.I.; Karhan, S.U.; Caylarbasi, Z.; Tural, U. (2005). "Photographic evidence of the occurrence of bramble shark, Echinorhinus brucus (Bonnaterre, 1788) (Squaliformes: Echinorhinidae) from the Sea of Marmara" (PDF). Annales Series Historia Naturalis. 15 (1): 51–56. Archived from the original (PDF) on 2013-09-27. Retrieved 2012-03-25.
  10. ^ Martin, R.A. "Echinorhiniformes: Bramble Sharks". ReefQuest Centre for Shark Research. Downloaded on March 24, 2012.
  11. ISBN 978-0-8018-6048-5
    .
  12. doi:10.1111/j.1439-0426.2010.01615.x
    .
  13. ISBN 978-0-674-03411-2
    .
  14. ^ a b Joel, J.J.; Ebenzer, I.P. (1991). "On a bramble shark with 52 embryos" (PDF). Indian Council of Agricultural Research Marine Fisheries Information Service Technical and Extension Series (Suppl. 108): 15, 31.
  15. ^ Silas, E.G.; Selvaraj, G.S.D. (1972). "Descriptions of the adult and embryo of the bramble shark Echinorhinus brucus (Bonnaterre) obtained from the continental slope of India" (PDF). Journal of the Marine Biological Association of India. 14 (1): 395–401.
  16. OCLC 1042901090
    .

External links

Wikimedia Commons has media related to Echinorhinus brucus.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Bramble_shark&oldid=1168691176"