The blue ling is a medium to large sized, very long and slender codfish. Usual size in catches is 28 to 43 inches, but the largest individual caught in Icelandic waters measured 60 inches. It is found all around Iceland, but is much rarer in the colder waters north and east of the country. It is primarily a deep water fish, found in the depth range of 425 to 4900 feet but mostly at a depth of between 980 and 2600 feet. It is found in European waters from Murmansk and into the Mediterranean Sea. It also occurs around the Faroe Islands, and has been reported in waters off southern Greenland and on the Grand Banks, off Canada.
Blue ling feeds primarily on other fishes, but also, to a lesser extent, on benthic invertebrates. Spawning takes place in deep waters off the south and west coasts, from February to April. Growth is rather slow and the fish reach sexual maturity at the age of 9 to 11 years, measuring 30 to 35 inches. The blue ling can reach 20 years of age.