Burbot

The burbot (Lota lota) is the only member of the cod family that lives entirely in fresh water — a long, slender, mottled bottom-dweller of cold lakes and rivers across the Northern Hemisphere, instantly known by its single chin barbel and eel-like tail. Its lean, firm, snow-white flesh is mild and faintly sweet, and its outsized, delicate liver is a prized delicacy, earning the fish nicknames such as "poor man's lobster" and the French lotte de rivière.