Lake trout have been observed spawning in depths from only a few 

 inches to 1 68 feet. The spawning act is usually accomplished by two or 

 more males crowding about a single female and pressing against her 

 sides until spawning is completed. Usually this is accompanied by con- 

 siderable splashing and thrashing around, especially obvious in shallow 

 water. Eggs are broadcast over the rocky bottom where they roll into 

 the deep crevices, and are protected from predation. Eggs hatch in 

 from 140 to 166 days at a water temperature of 37'F. Little or nothing 

 is known of young lake trout once they emerge from the sac fry stage. 

 Since they have never been found in the shallow water the speculation 

 can be made that they migrate to deep water immediately after they are 

 able to swim and take food. 



The adult lake trout is primarily a fish eater, preferring smelt, 

 whitefish, and freshwater sculpin. In some lakes, where the forage fish 

 supply is inadequate, they subsist largely on aquatic invertebrates and 

 various forms of plankton. 



Growth rate of lake trout is variable depending on the environment 

 offered by the individual lake. Sexual maturity cannot be established at 

 any definite age or length, but under average conditions male lake trout 

 will become sexually mature at four years (total length 13" to 15") and 

 females will reach sexual maturity at six or seven years (total length 

 17.5" to 19.0"). 



Ages of lake trout have been estimated at 20 to 40 years for some 

 large lake trout in certain lakes in Canada. The oldest fish recorded in 

 our Maine studies was 13 years old and weighed 21 pounds. 



Average lengths of togue from three Maine lakes are listed below 

 by age: 



Fishing for lake trout, considered by many fishermen as an art, is 

 growing in popularity each year. The most successful anglers obtain 

 best results using a lead-core line, heavy spinners, and "sewed-on" smelts 

 trolled in deep water over bars where the lake trout feed. Other fisher- 



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