NATURAL HISTORY, TORONTO REGION 



in it. Commercially, however, it is of great impor- 

 tance, being always in demand and furnishing an 

 excellent article of food. 



29. Brook Trout. Salvelinus fontinalis (Mitch- 

 ill). Brook Trout were formerly abundant in all 

 the spring streams near Toronto, but of late years, 

 owing to the pollution of the water and incessant 

 fishing, they have become nearly exterminated. The 

 size attained by this fish depends largely upon its 

 habitat and food. In small streams it may mature 

 at a length of six or eight inches and a weight of only 

 a few ounces, while in large bodies of water, with an 

 abundant food supply, they will reach eighteen inches 

 or more in length and a weight of from six to eight 

 pounds. In the cool days of late autumn the Brook 

 Trout run up to the headwaters of the streams, and 

 there, on the gravelly shallows, deposit their ova; 

 the spawning season extending from September in 

 the north to December in the south. The number 

 of eggs produced depends upon the age and size of 

 the fish. Yearlings (that is, fish in their second 

 year) will produce from fifty to two hundred and 

 fifty ova, while a large fish may produce as many as 

 fifteen hundred. The eggs are about three-sixteenths 

 of an inch in diameter and of a warm orange colour. 

 The period of hatching depends upon the tempera- 

 ture of the water, ranging from thirty-two days in 

 water at 54 to one hundred and sixty-five days in 

 water at 37. In the early parts of the summer 

 Trout frequent the ripples and shallower parts of 

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