Prickly shark

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Prickly shark

Data Deficient  (IUCN 3.1)[1]
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. cookei
Binomial name
Echinorhinus cookei
Range of the prickly shark[2]

The prickly shark (Echinorhinus cookei) is one of the two

dermal denticles, hence its common name
.

Data Deficient
.

Taxonomy

Austrian

new type specimen.[5] Other common names for this species include Cook's bramble shark and spinous shark.[1][6]

Description

The prickly shark has a flabby and cylindrical body, with the adults markedly bulkier than juveniles, and a short, moderately flattened head. The nostrils are placed far apart and preceded by small flaps of skin. The spiracles are tiny and positioned well behind the eyes, which lack nictitating membranes. The mouth forms a broad arch, with very short furrows at the corners. There are 21–25 and 20–27 tooth rows in the upper and lower jaws respectively. The knife-like teeth each have a strongly angled main cusp flanked by up to three smaller cusplets on either side; the lateral cusplets are absent in young sharks. There are five pairs of gill slits, with the fifth pair the longest.[7][8][9]

The

dermal denticles measuring up to 0.4 cm (0.16 in) across, which are never fused together as in the bramble shark. Each denticle is thorn-like, with strong ridges running down the central spine and radiating out over the star-shaped base. The denticles beneath the snout are very fine in adults. The prickly shark is plain brown or gray, often with a purplish tint, and has black trailing margins on the fins. The underside is paler, most obviously on the snout and around the mouth. It may reach a length of 4.0 m (13.1 ft). The maximum recorded weight is 266 kg (586 lb) for a 3.1 m (10 ft) long female.[7][8][9]

  • Head
    Head
  • Head, bottom view
    Head, bottom view
  • Jaws
    Jaws
  • Upper teeth
    Upper teeth
  • Lower teeth
    Lower teeth

Distribution and habitat

The prickly shark is widely distributed around the

Galapagos Islands, and off Peru and Chile.[10] This species generally seems to be uncommon; an exception is in Monterey Canyon off California, where sharks of both sexes are abundant throughout the year.[1][11][12]

Favoring cooler temperatures of 5.5–11 °C (41.9–51.8 °F), the prickly shark is mostly found below depths of 100–200 m (330–660 ft), particularly in the

dissolved oxygen levels, allowing it to inhabit oceanic basins inaccessible to other sharks.[13]

Biology and ecology

The prickly shark and the bluntnose sixgill shark (pictured) prey on each other's young.

The prickly shark is a slow swimmer and has been observed hovering just above the

schooling fishes. Individual sharks seldom strayed from the local area and had very small home ranges, no more than 2.2 km2 (0.85 sq mi).[11][12] The prickly sharks in Monterey Canyon regularly form aggregations that may number over thirty.[7]

The size and structure of the prickly shark's mouth and

aplacental viviparous, with the unborn young sustained by yolk. There is only one known record of a pregnant female, which was gestating 114 embryos; this ranks among the largest known litters from any shark. The young are probably under 40 cm (16 in) long at birth.[7] The length at sexual maturity has not been precisely determined but is thought to be around 2.0 m (6.6 ft) for males and 2.5–3.0 m (8.2–9.8 ft) for females.[15]

Human interactions

Interactions with divers show that the prickly shark behaves inoffensively towards humans, either tolerating contact or fleeing when closely approached.

gillnets, or line gear.[8] It has little commercial value since the meat is soft and poorly regarded.[9]

Conservation status

In June 2018 the New Zealand

Data Deficient, citing its patchy known distribution and the continuing expansion of deepwater fisheries.[1]

References

  1. ^
    doi:10.2305/IUCN.UK.2018-2.RLTS.T41802A68622003.en
    . Retrieved 18 November 2021.
  2. ISBN 9780691120720
    .
  3. ^ Pietschmann, V. (1928). "Neue Fischarten aus dem Pazifischen Ozean" [New fish species from the Pacific Ocean]. Anzeiger der Akademie der Wissenschaften in Wien (in German). 65 (27): 297–298.
  4. ^ Pietschmann, V. (1930). "Remarks on Pacific fishes". Bernice P. Bishop Museum Bulletin. 73: 1–244.
  5. ^ Garrick, J.A.F. (1960). "Studies on New Zealand Elasmobranchii. Part X. The genus Echinorhinus, with an account of a second species, E. cookei Pietschmann, 1928, from New Zealand waters" (PDF). Transactions of the Royal Society of New Zealand. 88 (1): 105–117.
  6. ^ Froese, R.; Pauly, D. (eds). "Echinorhinus cookei". FishBase. March 2012 Version. Downloaded on March 25, 2012.
  7. ^
    ISBN 9780195392944
    .
  8. ^
    ISBN 978-9251013847
    .
  9. ^
    ISBN 978-0520222656
    .
  10. ^
    S2CID 85331266
    .
  11. ^
    doi:10.3354/meps08067
    .
  12. ^ a b Dawson, C.L. (2007). "Prickly shark, Echinorhinus cookei, movement and habitat use in the Monterey Canyon Archived 2014-05-21 at the Wayback Machine". M.Sc. Thesis, San Francisco State University.
  13. ^ Barry, J.P.; Maher, N. (2000). "Observation of the prickly shark, Echinorhinus cookei, from the oxygen minimum zone in Santa Barbara Basin, California". California Fish and Game. 86 (3): 213–215.
  14. ^ Martin, R.A. "Echinorhiniformes: Bramble Sharks". ReefQuest Centre for Shark Research. Downloaded on March 25, 2012.
  15. ISBN 978-0674034112
    .
  16. OCLC 1042901090
    .

External links

Wikimedia Commons has media related to Echinorhinus cookei.

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