Birdbeak Dogfish

 Birdbeak Dogfish

  • Scientific name: Deania calcea
  • Also know as: Shovelnose Spiny Dogfish, Brier Shark
  • Size: Up to 3ft in length
  • UK minimum size: N/a
  • UK shore caught record: N/a
  • IUCN status: LC (Least Concern) overall but EN (Endangered) in European waters.
  • Distribution: Deep water areas around the British Isles such as Rockall Trough and Faroe-Shetland Channel.
  • Feeds on: Fish and squid make up most of the diet, although crustaceans and prawns may also be taken.
  • Description: Slim, long body and a distinctive long snout which gives this species its name. Two dorsal fins are present, the first of which is elongated with a short spine at the front and the second is higher with a larger spine. No anal fin is present. Eyes are large and appear green in colour and mouth is full of small sharp teeth and skin in brown to grey and very rough.

The birdbeak dogfish is an unusual looking deep-sea dogfish species which has a worldwide distribution. It is found in deep water areas around the British Isles but the depths at which it lives mean that it rarely comes into contact with humans, other than deep-sea commercial fishermen.

Distribution

The birdbeak dogfish lives in feeds in waters of around 200 to 1500 metres. This means that in British waters it is mainly found around the Rockall Trough and Faroe-Shetland Channel, although it will show up occasionally in deep waters elsewhere around the UK.

Birdbeak Dogfish Distribution
Distribution of the birdbeak dogfish is shown in the map above. Non-European populations (blue) are classed as Least Concern, whereas European stocks (orange) are classed as Endangered by the IUCN.

Its range extends throughout European waters where it is found as far northwards as Iceland and along the Atlantic coasts of France, Spain and Portugal, with its distribution continuing along the western coast of the African continent. There are several other populations in the world in areas such as Chile, South Africa, Australia, New Zealand and parts of Asia.

Life Cycle

Birdbeak dogfish snout
Birdbeak dogfish snout.

The birdbeak dogfish is a hunter. They will scour to seabed to feed on fish, crabs, prawns and lobsters which are present there, and will also move higher up the water column to hunt for any fish or squid which are present there. This species is not sexually mature until it is around twenty-five years old, and with life expectancy only being around thirty-five years this means that the birdbeak dogfish has a relatively short period in its life when it can reproduce. Litters generally consist of up to seven pups, although the gestation period of this species is unknown.

Conservation Status

The birdbeak dogfish is commercially valuable. There is limited demand for its flesh but its real value is in its oil-rich liver which contains a substance called squalene which can be used in both cosmetics and medicine. Once the liver has been removed the rest of this species can be processed into fishmeal. While the International Union for the Conservation of Nature (IUCN) classes this species as one of Least Concern overall, European populations are classed as Endangered. This is because deep-sea trawlers and long-liners increasingly targeted this species as catches were not limited by quotas. This caused birdbeak dogfish populations to plummet, with the IUCN stating that numbers declined by 89% between 1970 and 2012. Since then there have been conservation measures put in place such as a total allowable catch and allowable bycatch of zero. Conservation measures appear to be working and the IUCN state that numbers are very slowly increasing, although as the birdbeak dogfish cannot reproduce until it is around twenty-five years old it will take a very long time for stocks to rebuild and reach pre-1970s levels.