Bramble shark  (Echinorhinus brucus)

Classified as Data Deficient (DD) on the IUCN Red List (1).

The most unusual feature of this sluggish shark is the sharp tooth-like denticles scattered over its body and fins (2) (3). A stout-bodied animal with soft, flabby skin, the dorsal side of the bramble shark ranges in colour from dark grey through to olive, brown or black, while below it is a paler brown, grey or white. Metallic reflections are visible along its back and the denticles can appear luminescent, despite lacking any specialised luminous organs (2) (4). It notably lacks an anal fin and both dorsal fins are set well back on the body towards the tail, beginning just behind the start of the pelvic fin (2) (4) (5).

The bramble shark is known patchily from the North Sea, the western and eastern Atlantic Ocean, the Indian Ocean and the western Pacific Ocean (1) (2).

A deepwater, bottom-dwelling shark, found mainly at depths of 400 to 900 metres, on the upper and middle continental shelf (1) (2).

A sluggish, bottom dwelling species, very little is known about the life history of the bramble shark, but it is thought likely to be slow growing and late maturing (1) (2) (4). With bony fish, small sharks and crustaceans being common prey, it is probably capable of short bursts of speed whilst hunting (1).

Employing an ovoviviparous reproductive mode, the 15 to 20 pups that comprise a litter, develop within eggs inside the mother’s body and emerge alive after hatching (1) (2). Nothing is known about the length of time the pups take to develop or the amount of time between successive breeding (1).

Frustratingly little is known about the conservation status of this seemingly rare deepwater species. Although the bramble shark is probably not a frequent component of fisheries bycatch, there is some evidence that it is declining in the Northeast Atlantic. The concern is that if the bramble shark does exhibit a slow rate of reproduction, as is suspected, it is that much more susceptible to a rapid decline in population size (1).

In the absence of adequate information to determine the conservation status of the bramble shark, it is currently classified as Data Deficient on the IUCN Red List (1). Consequently, further research into this species’ biology and population is vital before any necessary conservation measures can be implemented.

View information on this species at the UNEP World Conservation Monitoring Centre.

To find out more about the conservation of sharks see:

• Save Our Seas Foundation:
  www.saveourseas.com
• The Shark Research Institute:
  www.sharks.org