Gulper shark (Centrophorus granulosus)

Found lurking in deep waters, the gulper shark (Centrophorus granulosus) is a long and slender fish with a long snout and large, green eyes. Like all dogfish, the gulper shark has two dorsal fins bearing long, grooved spines. The second dorsal fin is smaller than the first, and there is no anal fin ^{(2) (3)}.

The upperparts of the gulper shark are olive-grey to grey-brown, and its underside is lighter. The adult has no obvious markings. The juvenile gulper shark is lighter than the adult, and has white-tipped dorsal and caudal fins ^{(2) (3)}.

French

Squale-chagrin Commun.

Spanish

Quelvacho.

Size

Adult male length: up to 85 cm ⁽¹⁾

Adult female length: up to 102 cm ⁽¹⁾

Newborn size: 30 - 42 cm ⁽²⁾

The gulper shark inhabits deep waters, living in schools and predating on small fish and on invertebrates such as hake and cephalopods ^{(1) (2)}.

This species can live for more than 30 years, with the female gulper shark reaching maturity between 12 and 16 years, and the male between 7 and 8 years ⁽¹⁾.

The gulper shark has an exceptionally long gestation period of two years. The unfertilised egg cell of the gulper shark reaches one of the largest cellular sizes described for any animal, weighing between 143 and 370 grams. The gulper shark is ovoviviparous, producing eggs which hatch inside the females’ body. The components of the egg and any unfertilised eggs are used to nourish the developing pup, which is then born live ⁽⁴⁾.

A long gestation period, one pup per litter, late maturity and occasional resting periods between pregnancies mean that the gulper shark has an extremely low reproductive rate, with probably has the lowest reproductive potential of any elasmobranch ⁽¹⁾.

The gulper shark can be found in both temperate and tropical waters ⁽²⁾. It is found in the Atlantic, Pacific and Indian Oceans as well as the Mediterranean and Black Sea. Populations of the gulper shark in the southeasten Atlantic Ocean may represent a separate species ⁽¹⁾.

A demersal species, the gulper shark is found lurking on or near the substrate on upper slopes and along continental shelves at depths of up to 1,400 metres. Juvenile gulper sharks are thought to live in deeper water than the adults ⁽¹⁾.

The gulper shark is classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾.

Overfishing poses the main threat to the gulper shark. This species is heavily fished for its liver oil and meat. Even with moderate fishing levels, the low reproductive rate of the gulper shark means that population numbers may be severely depleted if not properly managed ⁽¹⁾.

Globally, there is a general trend for fisheries to exploit deeper fishing grounds using methods such as bottom trawling and bottom longlines. Population levels of the gulper shark have decreased by 80 to 95 percent in the northeast Atlantic since 1990 ⁽¹⁾. In the Mediterranean, gulper shark aggregations are targeted by fisheries using longlines and gillnets ^{(1) (5)}. The gulper shark is also caught as bycatch in bottom trawls and long line fisheries that target other species, further depleting its population levels ⁽¹⁾.

Currently in the northwest and southeast Atlantic there are no specific conservation measures in place for the gulper shark. In 2005, the General Fisheries Commission for the Mediterranean (GFCM) banned fishing at depths below 1,000 metres in the Mediterranean; however, the gulper shark can often be found above this depth ⁽¹⁾. The International Council for the Exploration of the Sea (ICES) has also recommended that there should be no deepwater fisheries of sharks ⁽⁵⁾.

Futher research is also required into the biology, taxonomy and populatons of the guler shark, and the fishing pressures on this species need to  be monitored ⁽¹⁾.

More information on the gulper shark:

• The Florida Museum of Natural History - Gulper shark:
  http://www.flmnh.ufl.edu/fish/Gallery/Descript/gulpershark/gulpershark.html

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

This species information was authored as part of the Arkive and Universities Scheme.

Anal fin

In fish, an unpaired fin on the under surface of the fish, behind the anus.

Bycatch

In the fishing industry, the part of the catch made up of non-target species.

Caudal fin

The tail fin of a fish.

Cephalopods

A group of marine molluscs with grasping tentacles and either an internal or external shell. Includes squids, octopuses, cuttlefish and nautiloids.

Continental shelf

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

Demersal

Fish that live on or near the ocean bottom. They are often called benthic fish, groundfish, or bottom fish.

Dorsal fin

The unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans (whales, dolphins and porpoises).

Elasmobranch

A member of a group of cartilaginous fish that includes sharks, skates and rays.

Gestation

The state of being pregnant; the period from conception to birth.

Invertebrates

Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Ovoviviparous

Producing young which develop from eggs that are retained inside the female’s body and are nourished by their yolk sac until they hatch; the young are then born live.

Taxonomy

The science of classifying organisms, grouping together animals which share common features and are thought to have a common ancestor.

Temperate

Referring to the geographical region that lies between the polar and tropical regions, characterised by a moderate climate with distinct seasons.

1. IUCN Red List (August, 2011)
   http://www.iucnredlist.org/
2. The Florida Museum of Natural History - Gulper shark (August, 2011)
   http://www.flmnh.ufl.edu/fish/Gallery/Descript/gulpershark/gulpershark.html
3. Shark Trust (2010) An Illustrated Compendium of Sharks, Skates, Rays and Chimaera. Chapter 1: The British Isles and Northeast Atlantic. Part 2: Sharks. The Shark Trust, Devon, UK. Available at:
   http://www.sharktrust.org/do_download.asp?did=35262
4. Guallart, J.V. (2001) Changes in composition during embryo development of the gulper shark, Centrophorus granulosus (Elasmobranchii, Centrophoridae): An assessment of maternal-embryonic nutritional relationships. Enviormental Biology of Fishes, 61: 135-15.
5. OSPAR Commission (2010) Background Document For Gulper Shark Centrophorus granulosus. OSPAR Commission, London. Availableat: http://qsr2010.ospar.org/media/assessments/Species/P00472_gulper_shark.pdf?zoom_highlight=gulper%2Bshark#search="gulper shark”