2QO 



PRACTICAL ZOOLOGY 



the earliest settlement of America the cod has been the most 

 valuable of our Atlantic coast fishes. Indeed, the codfish of 

 the Banks of Newfoundland was one of the principal induce- 

 ments which led England to establish colonies in America." 

 The total weight of the codfishes landed at Boston and Glouces- 

 ter in 1908 was 41,615,277 pounds, valued at $1,042,683. The 

 Bureau of Fisheries distributes millions of fry every year. 



FIG. 171. Flounder. (From U. S. Fish Manual.) 



Fresh-water Food Fishes. The food fishes mentioned thus 

 far are all marine species. There are, however, a great many 

 fresh-water fishes of commercial importance. Some of these are 

 mentioned in Chapter XXX; namely, the sturgeons, paddle- 

 fishes, suckers, carp, and catfishes. Others are the whitefish, 

 lake trout, pike perch, and salmon. 



The common whitefish (Fig. 172) occurs throughout the Great 

 Lakes region. During the winter it prefers deep water, but 

 in the spring it migrates to the shallow water to secure insect 

 larvae which become abundant at that time. It migrates to 

 shallow water again in the autumn to spawn. The mouth is on 

 the under side, and the crustaceans, mollusks, and other animals 

 used as food are picked up from the bottom. The eggs are laid 



