92 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



FOOD, SIZE, ETC. 



The brook trout has a voracious appetite and takes advantage of 

 every oi^portuiiity to satisfy it except in the spawning season, when it 

 takes no food at all. It is strictly a carnivorous fish, its food consisting 

 chiefly of Crustacea, raollusca, and various forms of insects and worms. 

 When pressed with hunger it does not hesitate to devour its own kind. 



The size of these fish varies iu difierent localities, usually in propor- 

 tion to the abundance of natural food and to the size of the body of 

 water in which they are found. They seldom, however, exceed 2 pounds. 

 The Au Sable Eiver trout will rarely run as large as 2J to 3 pounds, but 

 in other rivers of Michigan larger examples are occasionally found. In 

 southern New York they seldom weigh over 2 pounds, while in the 

 Eangeley Lakes, of Maine, they have been caught weighing 10 pounds. 

 The rate of growth also varies with the surrounding conditions and is 

 more rapid iu water of higher temperature and with a plentiful supply 

 of food. Under favorable circumstances an average growth for the 

 first year is from f to 1 ounce, in two years 8 to 10 ounces, in three years 

 about 1 pound. 



While not of any considerable commercial importance, the brook 

 trout is highly esteemed as a table delicacy on account of the flavor 

 and quality of its flesh, and, as it is very gaaie, it is much sought after 

 by sportsmen. Those from clear, swiftly flowing streams do not grow 

 so large as those found iu quiet and deeper waters, but are superior in 

 quality and appearance. 



RANGE, SPAWNING, ETC. 



The natural range of the brook trout in the United States is from 

 Maine to Georgia and westward through the Great Lakes region to 

 Minnesota, and iu Canada from Labrador to the Saskatchewan. Owing 

 to its hardy nature and ability to adapt itself to new surroundings, it 

 may be successfully transplanted into suitable streams, and has been 

 extensively introduced into waters to which it was not native, in Mich- 

 igan, Wisconsin, and Minnesota, many of the waters of the Rocky 

 Mountains and the Pacific Coast, the Eastern States, and the creeks 

 and rivers of the Alleghany range of mountains. With the i^ossible 

 exceptions of the rainbow trout and steelhead it is the hardiest mem- 

 ber of the salmon family and will make a brave struggle for existence 

 even with adverse surroundings. All streams can not be successfully 

 stocked with this species; the temperature of the water must not be too 

 high nor the flow too sluggish, although an unfavorable temperature is 

 no serious obstacle if the speed of the current is great enough to insure 

 a sufficient aeration of the water, or if there are creeks fed by springs 

 flowing into the main stream to which the fish can run. The best 

 streams are those with a gravelly bottom, clear shallow water, and a 

 steady current, and waters to be stocked must contain a sufficient 

 amount of natural food and suitable places for spawning. 



