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Becker, George C. / Fishes of Wisconsin
(1983)

Cod family - gadidae,   pp. 745-751 ff. PDF (2.7 MB)


Page 747

 
Burbot   747 
Burbot 
Lota Iota (Linnaeus). Lota-the ancient name used by 
     Guillaume Rondelet, a French zoologist; in 
     French, la Lotte. 
Other common names: lawyer, lake lawyer, ling, ling 
     cod, eelpout, freshwater cod, cusk, spineless 
     catfish, gudgeon, mud blower, mother eel 
     (Kansas), maria (Saskatchewan, Manitoba, 
     northern Ontario), methy (northern Canada), 
     lush (Alaska), dogfish (Minnesota). 
258 mm, Beaver Cr. (Trempealeau Co.), 28 June 1977 
DESCRIPTION 
Body elongate, cylindrical anterior to anus; laterally 
compressed posterior to anus. Length 305-483 mm 
(12-19 in). TL = 1.08 SL. Depth into SL 6.2-7.7. Head 
into SL 4.4-4.8; head flattened dorsoventrally. Snout 
pointed; upper lip groove continuous over tip of 
snout. Mouth large, almost horizontal; posterior edge 
of upper jaw behind pupil of eye; numerous minute 
teeth in wide bands on upper and lower jaws. One 
median chin barbel, and barbel-like, tubular exten- 
sions for each nostril opening. Dorsal fins 2; first 
dorsal low, short with 8-16 rays; second dorsal low, 
long with 61-81 rays. Anal fin rays 52-76; pelvic fin 
rays 5-8, the second ray prolonged into a tapering 
filament. Scales cycloid, embedded in cheeks, oper- 
cles, and body, so small as to be almost invisible ex- 
cept in large adults; under microscope the scales have 
heavy circuli which appear like growth rings in a 
gymnosperm twig; lateral line complete. Pyloric caeca 
31-150. Large liver without gall bladder. 
  Adults uniformly yellow, or light brown to black, 
or mottled with dark brown or black on back and 
sides; belly whitish. Young fish conspicuously speck- 
led, or with dark vermiculations. Dorsal, caudal, and 
anal fins mottled and more or less dark edged; pec- 
toral fins mottled; pelvic fins white to slightly pig- 
mented. 
DISTRIBUTION, STATUS, AND HABITAT 
In Wisconsin, the burbot occurs in all three drainage 
basins and in all boundary waters. Its distribution is 
mainly associated with the St. Croix, Chippewa-Red 
Cedar, Wisconsin, Rock, and Wolf-Fox river systems. 
Its distribution in the unglaciated portion of the state 
is sporadic. 
  The chronology of the changes in abundance of 
burbot in Lake Michigan suggests that the sea lam- 
prey was responsible for the burbot's decline in the 
mid-1940s, and that sea lamprey control led to an 
upswing in burbot numbers in the late 1960s. (Wells 
and McLain 1972). The burbot is uncommon in the 
Mississippi River, although at one time it was re- 
ported as common in Lake Pepin (Wagner 1908). It is 
common in the Flambeau watershed and in the tri- 
butaries to Lake Superior; it is abundant in Lakes 
Poygan and Winnebago. Its status in Wisconsin ap- 
pears to be secure. 
  The burbot frequents cool waters of large rivers, 
and the lower reaches of their tributaries, and lakes- 
particularly in northern Wisconsin. It is encountered 
most frequently at depths over 1.5 m (immatures at 
lesser depths) over substrates of mud, sand, rubble, 
boulders, silt, and gravel. It was found in streams of 
the following widths: 1-3 m (13%), 3.1-6.0 m (25%), 
12.1-24.0 m (25%), and more than 50 m (38%). It pre- 
fers patches of plants and trash when young, stony- 
bottomed riffles when half-grown, and undercut 
banks when adult (Hubbs and Lagler 1964). 
BIOLOGY 
The burbot is the earliest spawner of all Wisconsin 
fishes. Spawning occurs in mid-winter, or in the early 
spring before the ice has melted. In the Lake Michi- 
gan basin, adults spawn from January to March. In 
Lake Winnebago, burbot spawn on rock and gravel 
reefs from late January to early February (Weber 1971). 
In the Bayfield area of Lake Superior, most burbot 
collected had spawned by late February and early 
March; spawning in the Apostle Islands region may 
continue into late March (Bailey 1972). 
  Burbot spawn in deep water in some areas, but the 
spawning site is usually in shallow bays in 0.3-1.2 m 
(1-4 ft) of water over sand or gravel, or on gravel 
shoals 1.5-4.6 m (5-15 ft) deep. Spawning usually 
takes place at night, and the spawning grounds are 
deserted in the daytime. The surface water temper- 
ature is close to freezing; no nest is built, and no care 
is given the young. 
  The spawning act of the burbot has been observed 
a number of times. E. Fabricius noted (Breder and 
Rosen 1966:376): 
The female slowly swam about on a sand bottom in a tilted 
posture, with lifted tail and her head pointed downwards, 
dragging the chin barbel and the prolonged second rays of 
the pelvics along the ground. The male approached her from 


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