LAKE TROUT 



Cristivomer namaycush (Walbaum) 



Stuart DeRoche 

 Regional Fishery Biologist 



Lake trout, more commonly called togue in Maine, are distributed 

 from Labrador to Alaska, south to California, and through the Great 

 Lakes to northern New England. Distribution in Maine is confined to 

 the large, deep, coldwater lakes, and they thrive best in lakes with 

 irregular bottom contours and with shore lines covered with boulders 

 and gravel. The lake trout is the second largest member of the salmon 

 and trout family with recorded weights of as much as 80 pounds. 



Lake trout are lake dwellers; however, in more northern latitudes 

 where water temperatures are not a limiting factor, they are occasionally 

 found in rivers. During spring and fall when the waters are cold these 

 fish may inhabit shallow water, but at other times they live in deep water 

 where temperatures are colder and more favorable. Lake trout have 

 been taken at depths exceeding 300 feet. 



In Maine, lake trout can be found in shallow water over a coarse 

 gravel or boulder-covered bottom from mid-October until mid- 

 November engaged in their annual spawning activity. Spawning com- 

 mences with the males entering the spawning area first. Unlike most 

 other species of trout and salmon no nest is prepared. However, the 

 males appear to clean the rubble by swimming close to the bottom and 

 occasionally flipping the rocks with their caudal fins and peduncles. 

 Evidence that lake trout have "worked" an area is apparent in the rather 

 large areas of silt-clean rocks and gravel. A few days later females enter 

 the area and spav/ning commences. The spawning season is approxi- 

 mately 20 days. No particular changes occur in either sex during spawn- 

 ing season as is common in other members of the salmon and trout 

 family. 



Tagging experiments in Maine have established definitely that lake 

 trout, once sexual maturity has been reached, return each year to 

 spawn. The number of years a lake trout will spawn successfully varies, 

 but growth curves from various Maine lakes indicate a heavy natural 

 mortality after the ninth or tenth year. Thus a maturity of five or six 

 years for males and three or four years for females would be possible. 



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