The only freshwater member of the Gadidae family of codﬁsh found in North America, Europe, and Asia, the burbot is often caught accidentally by anglers fishing for other species. Although it is a popular food ﬁsh in Europe, its ugly appearance makes it unappetizing to a fussy majority of Americans. It is mainly sold in salted form for ethnic consumption in North America but is also a source of oil and is processed into ﬁshmeal; the liver is high in vitamins A and D and is sold smoked or canned in Europe.
IdentificationThe elongate shape of the burbot resembles an eel or a cross between an eel and a catﬁsh. It has been mistaken for a catﬁsh, and in some places it is called an eel, although it is neither. It also looks like a smaller and slimmer version of the saltwater cod.
Other distinctive features include tubular nostrils, a single chin barbel, and a rounded tail. The soft-rayed fins are also noteworthy in appearance: The pectoral ﬁns are large and rounded, the ﬁrst dorsal ﬁn is small and short, and the second dorsal and anal ﬁns start near the middle of the body and continue to the tail. It has a wide head, small eyes, and small, embedded scales that produce a slick skin.
The burbot has a mottled appearance, due to a dark brown or black pattern scattered over a yellow, light brown, or tan background; there may be regional color variations, including light brown, dark brown, dark olive, or even yellow. The anal ﬁns have a dark edge to them.
Size/AgeFull-grown ﬁsh average 15 inches in length and less than a pound in weight. Burbot that are caught by anglers usually weigh several pounds and are occasionally in the 8-pound class, although they can grow much larger. An 18-pound, 11-ounce ﬁsh holds the all-tackle world record, but Alaska has produced larger ﬁsh, at least one of which was reportedly almost 60 pounds. Some are able to live for 20 years.
Spawning behaviorBy the time it is 3 years of age, the burbot is sexually mature. It is one of the few species that spawns in mid- or late winter under ice, doing so at night in shallow bays in 1 to 4 feet of water over sand or gravel; occasionally, it will spawn in rivers in 1 to 10 feet of water. A burbot may produce more than a million spherical, amber eggs at one time, although the average amount is half that number. Without a nest or parental protection, the eggs hatch in 4 to 5 weeks.
Food and feeding habitsYoung burbot feed on plankton and insects, graduating to a diet made up almost entirely of ﬁsh, especially perch, cisco, and whiteﬁsh. They will also eat mollusks, ﬁsh eggs, plankton, and crustaceans. Rocks and other indigestible items have been found in their stomachs.