The blue hake lives in deep waters in every ocean around in the globe. Sometimes found at depths of nearly 3000 metres, it has not been extensively studied by scientists, nor is it particularly attractive as a commercial fish. In Canadian waters, populations exist off the coasts of the Atlantic provinces and Baffin Island. Little is known about the life cycles of these fish, but it is thought that they might migrate into deeper waters to spawn.

The blue hake is normally grey-blue or brownish-blue to nearly black, with a flat nose and slightly indented tail. It has two dorsal fins, the second of which spans most of its body length. Females usually grow up to 75 cm, while males may grow to only about half that length.