Dumb gulper shark (Centrophorus harrissoni)

Description

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Dumb gulper shark fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Dumb gulper shark description

The dumb gulper shark is a relatively little-known deepwater species ⁽³⁾, with a long, robust head, a long, flattened snout, large mouth and huge eyes ^{(2) (3)}. The body is slender and of moderate size ^{(2) (4)}, and is grey to greyish-brown in colour, with a paler underside ⁽³⁾. There are two dorsal fins, the first larger than the second, and each has a short spine ^{(2) (3) (4)}, a white rear margin, and a dark blotch towards the front, which is more distinct in juveniles ⁽²⁾. The large caudal fin is asymmetrical, with a longer upper than lower lobe ^{(3) (4)}.

The broad, blade-like teeth of the dumb gulper shark differ between the upper and lower jaws, with the lower teeth being much larger ^{(2) (3)}. Interestingly, the teeth also differ between the male and female, with the male having much more erect, upright upper teeth, and upward-curving tips on the lower teeth ⁽²⁾. The dumb gulper shark is very similar in appearance to the closely related little gulper shark, Centrophorus uyato, and is possibly not a distinct species ⁽³⁾.

Also known as

dumb shark, Harrison's deepsea dogfish, Harrison's dogfish, longnose gulper shark.

Size

Total length: up to 111 cm ⁽²⁾

Dumb gulper shark biology

Relatively little information is available on the biology of the dumb gulper shark. It feeds on fish, particularly small, deep-sea fish of the family Myctophidae (lanternfishes), as well as on crustaceans and cephalopods ⁽¹⁾. It is likely to mature at a relatively late age ⁽¹⁾, with the smallest mature males recorded to be a length of around 82 centimetres ⁽²⁾, and to be long-lived, with closely related species known to live for up to an impressive 46 years or more ⁽¹⁾. The female dumb gulper shark is presumed to give birth to live young ⁽⁵⁾, and to have a low reproductive rate, producing only one or two pups every one to two years ⁽¹⁾.

Dumb gulper shark range

Although once believed to range along both the west and east coasts of Australia, the western form is now thought to be a separate species, and so the dumb gulper shark is now believed to occur only in the waters around New South Wales, Victoria, Queensland and Tasmania ^{(1) (2)}. It has also been recorded off New Zealand ⁽⁴⁾ and possibly New Caledonia ⁽²⁾, although possible records around Taiwan, the east coast of South Africa and the western North Atlantic are uncertain and need further investigation ^{(2) (3)}.

Dumb gulper shark habitat

The dumb gulper shark is found over the upper to middle continental shelf, where is lives near the sea bed, usually at depths of around 220 to 790 metres ^{(1) (2) (3)}.

Dumb gulper shark status

Classified as Critically Endangered (CR) on the IUCN Red List ⁽¹⁾.

Dumb gulper shark threats

The dumb gulper shark is subject to trawl fishing, and in New South Wales it is also harvested by droplining (in which long fishing lines, with a series of hooks, are set vertically down into the water). Dramatic population declines have occurred in some areas, with declines of over 99 percent recorded between 1976 to 1977 and 1996 to 1997, and the dumb gulper shark may now only be present in reasonable numbers in areas that cannot be trawled. Centrophorus species are harvested for meat and liver oil, but the low reproductive rate, late age of maturity and long lifespan typical of these deep-water sharks means that species such as the dumb gulper shark are unable to recover quickly after depletion ⁽¹⁾.

Dumb gulper shark conservation

In 2003, management changes to the South East Trawl Fishery (SETF) by the Australian Fisheries Management Authority brought in new limits to the permissible catch of dumb gulper sharks. In addition, the livers of Centrophorus species were not allowed to be retained unless the carcasses from which they were obtained were also landed. In Australia, recommendations have also been made to list the dumb gulper shark as an Endangered species on the Environmental Protection and Biodiversity Conservation (EPBC) Act, a listing that would require that a Recovery Plan be put in place for this little-known deepwater shark ⁽¹⁾.

Find out more

To find out more about the dumb gulper shark see:

• Compagno, L.J.V. (1984) Sharks of the World. An Annotated and Illustrated Catalogue of Shark Species Known to Date. Vol. 4: Part 1: Hexanchiformes to Lamniformes. Food and Agriculture Organization of the United Nations, Rome. Available at:
  ftp://ftp.fao.org/docrep/fao/009/ad122e/ad122e08.pdf
• FishBase:
  http://fishbase.fishinfo.cn/Summary/SpeciesSummary.php?id=649

For more information on shark conservation see:

• Save Our Seas Foundation:
  http://www.saveourseas.com/
• Project AWARE:
  http://www.projectaware.org/
• Shark Trust:
  http://www.sharktrust.org/

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Caudal fin

The tail fin of a fish.

Cephalopods

From the Greek for ‘head-foot’, a class of molluscs that occur only in marine habitats. All species have grasping tentacles, and either an internal or external shell. Includes nautiloids, cuttlefish, squids, octopuses, and extinct ammonites and belemnites.

Continental shelf

A region of relatively shallow water, not usually deeper than 200 metres, surrounding each of the continents.

Crustaceans

Diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.

Dorsal fin

The unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.

References

1. IUCN Red List (May, 2010)
   http://www.iucnredlist.org/
2. White, W.T., Ebert, D.A. and Compagno, L.J.V. (2008) Description of two new species of gulper sharks, genus Centrophorus (Chondrichthyes: Squaliformes: Centrophoridae) from Australia. In: Last, P.R., White, W.T. and Pogonoski, J.J. (Eds.) Descriptions of New Australian Chondrichthyans. CSIRO Marine and Atmospheric Research Paper No. 022, CSIRO, Australia.
3. Compagno, L.J.V. (1984) Sharks of the World. An Annotated and Illustrated Catalogue of Shark Species Known to Date. Vol. 4: Part 1: Hexanchiformes to Lamniformes. Food and Agriculture Organization of the United Nations, Rome. Available at:
   ftp://ftp.fao.org/docrep/fao/009/ad122e/ad122e08.pdf
4. Duffy, C.A.J. (2007) First record of Centrophorus harrissoni from New Zealand, with observations on squamation in Centrophoridae (Squaliformes). New Zealand Journal of Marine and Freshwater Research, 41: 163-173.
5. FishBase (May, 2010)
   http://fishbase.fishinfo.cn/Summary/SpeciesSummary.php?id=649