<Li> Scymnus micropterus (Valenciennes, 1832) </Li> <Li> Leiodon echinatum (Wood, 1846) </Li> <P> The Greenland shark (Somniosus microcephalus), also known as the gurry shark or grey shark, or by the Kalaallisut name eqalussuaq, is a large shark of the family Somniosidae ("sleeper sharks"), closely related to the Pacific and southern sleeper sharks . The distribution of this species is mostly restricted to the waters of the North Atlantic Ocean and Arctic Ocean . </P> <P> It has the longest known lifespan of all vertebrate species (estimated to be between 300--500 years), and is among the largest extant species of shark . As an adaptation to living at depth, it has a high concentration of trimethylamine N - oxide in its tissues, which causes the meat to be toxic . Greenland shark flesh treated to reduce toxin levels is eaten in Iceland as a delicacy known as kæstur hákarl . </P>

What kind of sharks live in the arctic