The northern wolffish has a thickset body that resembles a fat, stumpy eel. However,
unlike eels, the wolffish has a well developed and separate caudal fin. The dorsal
fin is of a uniform width from the top of the head to the base of the caudal fin,
and the anal fin, which begins approximately halfway along the body, also ends
at the base of the caudal fin. In order to differentiate the northern wolffish
from the other three species, colouration is important; the body of the northern
wolffish has very little marking and is a uniform deep brown as opposed to the
others, which are striped or spotted. The northern wolffish can grow to a very
large size, with the average adult measuring 1.3 m in length and weighing up to
This fish is found in the arctic waters of both North America and Asia, and has
also been caught off Greenland and Iceland. Due to its large size and broad distribution,
it is a commercially important fish and contributes substantial poundage to catches.
However, there has been little study of its ecology or life history.