Greenland Shark

fieldmarks: Short, rounded snout, heavy cylindrical body and small precaudal fins, two spineless, equal-sized dorsal fins, no anal fin, long ventral caudal lobe, first dorsal fin on back slightly closer to pelvics than pectoral fins, interdorsal space greater than distance from snout to second gill slits, no keels on base of caudal fin, upper teeth lanceolate, lower teeth with short, low, strongly oblique cusps and high, narrow roots. Head moderately long, length from snout to pectoral fins 23% total length in specimen 299 cm total length. Cusps of lower teeth short and low, strongly oblique, roots very high. Total tooth rows 45 to 52/48 to 53. Insertion of first dorsal fin slightly closer to pelvic bases than pectoral bases; interdorsal space greater than distance from snout tip to second gill slits. No lateral keels present on base of caudal fin. Caudal peduncle short, distance from second dorsal insertion to upper caudal origin less than twice second dorsal base, distance from pelvic insertions to lower caudal origin less than dorsal caudal margin. Vertebral column without well-defined calcified centra, notochord secondarily expanded. Size large, exceeding 4 m.

Maximum total length at least 640 cm and possibly to 730 cm, but most adults between 244 to 427 cm; adult males reach at least 343 cm, adult females at least 500 cm. Size at birth uncertain, but probably full-term fetuses were 37 cm long.

An abundant littoral and epibenthic shark of the continental and insular shelves and upper slopes down to at least 1200 m. The Greenland shark is one of the larger sharks and by far the largest of Atlantic-Arctic and Antarctic fishes. In the Arctic and boreal Atlantic it occurs inshore in the intertidal and at the surface in shallow bays and river mouths during the colder months but tends to retreat into water 180 to 550 m deep when the temperature rises. At lower latitudes in the North Atlantic (Gulf of Maine and North Sea) it inhabits the continental shelves, and may move into shallower water in the spring and summer. In the southern hemisphere it is found in deep water (677 m) off South Africa and in 145 to 370 m depth off Kerguelen Island. Water temperatures of places inhabited by these sharks range from 0.6 to 12°C. This is a proverbially sluggish shark that gives almost no resistance to capture; individuals up to 4.9 m long have been lured to the surface with baits and hauled out of the water with gaffs. It is easily fished through holes in the Arctic ice. In the Arctic summer Greenland sharks usually are close to the bottom but swim up towards the surface for prey. Development is ovoviviparous; as most females taken are not gravid but have large numbers of large, yolky eggs, it was thought until relatively recently that the Greenland shark might be oviparous. One female 5 m long had 10 young about 37 cm long in 1 uterus; and these were presumably full term because their yolk-sacs were resorbed. Although seemingly slow-moving, this shark is apparently able to capture large and active prey. Fishes are important food items and include herring, spiny eels, salmon and char, smelt, a variety of gadoids including cod, ling, pollock, and haddock, several flatfish including Atlantic and Greenland halibut, wolf-fish, redfish (Sebastes ), sculpins, lumpfish, and skates and their egg-cases. The Greenland shark regularly devours marine mammals, including seals (a common prey item, presumably taken alive) and small cetaceans (possibly mostly as carrion); old stories of it attacking living great whales are apparently unfounded. Greenland sharks voraciously devour carrion and offal of all sorts from whaling, sealing, and fishing operations, and will gather to feast in great numbers around whaling stations, whale kills, fish processing operations, and ice flows with skinned seal carcasses. These sharks will glut themselves on such abundance, and seem insensate to blows from clubs or cutting instruments while gorging. Parts of drowned horses and an entire reindeer were found in large Greenland sharks. Other prey includes sea birds, squid, crabs, amphipods, marine snails, brittle stars, sea urchins, and jellyfish.The Greenland shark has an unusual copepod parasite that attaches itself to the corneas of the eyes; usually only a single copepod is present on each eye. The copepods are highly conspicuous and may even be luminescent; and it has been speculated that their relationship to the shark is mutualistic and beneficial, with the copepods serving as lures to bring prey species in proximity to their hosts. Field observations are necessarily, however, to determine if the parasites actually serve as lures.

The Greenland shark has long been fished in Greenland, Iceland and northern Norway for its liver oil, but its meat is also used fresh and dried for human and sled-dog food. The meat is toxic when fresh, unless carefully washed, but is harmless dried or semi-putrid. Eskimos have used the skin of the Greenland shark for making boots, and used the sharp lower dental bands as knives for cutting hair.Catches for this species were reported to FAO only for the years 1957,1963-66 and 1971, then since 1973 the total catch has been ranging from 19 to 157 t. The total catch reported for this species to FAO for 1999 was 51 t. The countries with the largest catches were Iceland (51 t). The Greenland shark is mostly fished with hooks and lines, longline gear or gaffs, but is often taken in seal and whale nets and end traps . According to Bonfil (1994), during the first half of this century Norway had a fishery for Greenland sharks. Myklevoll (1989c) reports that this fishery for the liver oil, operated both as a specialised activity and in combination with sealing. Myklevoll provides data that show this fishery peaked in 1934, when 17,201 hectolitres of liver oil were landed. According to Myklevoll (1989c) this fishery ceased in 1960 because of falling market prices for the oil rather than because of scarcity of fish. Castro et al. (in press) citing Jensen (1914) mention that a fishery for this species started in Greenland in the early 19th century, that by 1857 the catch was estimated at only 2,000-3,000 sharks per annum and in the 1910s it had grown to 32,000 sharks per year. Conservation Status : Given our poor knowledge about the Greenland shark, it has not yet been possible to assess this species for the IUCN Red List. Because of its size and habitat, it is expected to be a very slow growing shark that probably deserves a more careful approach for exploitation. Additional information from IUCN database Additional information from CITESdatabase