FAMILY SALMONIDAE 113 



of these inland lakes varies greatly, and we find a corresponding varia- 

 tion in the color, markings, and even the form and size of the fishes 

 themselves, depending principally on whether the water is clear or 

 brownish. The color of the flesh also varies from almost white in some 

 inland lakes to a deep pink in Lake Superior. 



In Minnesota lake trout are native in almost all the deeper lakes in 

 the northern part of St. Louis, Lake, and Cook counties and in several 

 lakes in Itasca and Koochiching counties, and are found in a few 

 isolated lakes south of these, where they have probably been introduced. 

 They are found in a few deep lakes in northern Wisconsin and in the 

 Upper Peninsula of Michigan. They are common in Lake Michigan. 

 They are still fairly abundant in Lake Superior, where angling for them 

 is now pursued with increasing favor. In the inland and border lakes 

 they seldom exceed 18 to 20 pounds in weight, but much larger ones, 

 weighing up to 100 pounds, are sometimes secured in Lake Superior. In 

 some of the small inland lakes the average fish does not exceed 3 pounds. 

 Cox (1897) reported a specimen from Pokegama Lake near Grand 

 Rapids, Minnesota (the southern limit of the range) weighing 25 

 pounds and measuring 42 inches. 



Although they can be taken with the fly in shallow waters during 

 the month of May, at all other seasons they can be secured only by 

 deep trolling. The depths required vary according to water tempera- 

 tures from 30 feet in June to 70 feet in the later part of July. When 

 other methods fail still-fishing with live minnows at a depth of 70 feet 

 or more is sometimes successful. In Lake Superior in midsummer it 

 is sometimes necessary to troll at depths down to 200 feet to secure 

 lake trout. Late in the summer they may be taken at the surface near 

 shore. Lake trout are good fighters when handled with reasonably light 

 tackle, but their fighting is generally confined to the depths. Under 

 certain conditions in such Minnesota inland lakes as Cherokee and 

 Little Saganaga they often clear the water in one or two leaps. 



In Lake Superior they spawn from the later part of September into 

 December, but in the inland lakes they spawn just at the closing of the 

 lakes with ice, which usually occurs early in November. These fishes 

 have been successfully reared to the age of 8 years in small cement 

 ponds at one of the Minnesota hatcheries. They proved to be exceeding- 

 ly hardy, more so than any other species of trout. Under confinement 

 they did not mature until 5 years of age. Small females, 16 to 20 inches 

 long, contained from 1500 to 2300 eggs. 



Lake trout are caught and sold commercially from the Great Lakes, 

 mostly from Lake Superior and Lake Michigan where they range at 

 least to a depth of 800 feet. The commercial fishermen take them with 

 large-mesh gill and pound nets and by long gangs of setlines, the hooks 

 of which are baited with small ciscoes. The commercial fishermen often 

 fish miles offshore. 



