FISH OF ONTARIO. 57 



Colour, upper parts pale olivaceous ; sides and below white, some- 

 what lustrous. 



This Whitefish under favourable circumstances reaches a large size. 

 One taken in Lake Erie a few years ago measured thirty-three inches in 

 length, twenty-five inches in cicumference, and weighed twenty pounds. 

 One taken at Whitefish Point, Lake Superior, weighed twenty-three 

 pounds. Another taken in Lake Erie in 1876 weighed seventeen pounds. 

 Such fish are, however, now very rare in this Province. In Manitoba 

 they are less uncommon. The average length of adults on our markets in 

 these days will be about twenty inches and the weight about three pounds 

 or a little more. 



It ranges through the Great Lakes region from the St. Lawrence to 

 Lake Superior, and thence westward to Alaska ; where it is replaced by a 

 closely allied form ; its northern limit is not positively known. 



Although this is one of the most abundant and at the same time the 

 most valuable of our commercial fish, its habits are not yet fullv under- 

 stood ; undoubtedly they vary very much according to locality ; the depth 

 of water, currents or their absence, and climatic conditions all having 

 some influence on the movements of the fish in search of food, and upon 

 the time and place of spawning. In some of our lakes there is a move- 

 ment of the Whitefish in early summer from the deep water into shoal 

 water near the shore ; towards midsummer they retreat to the deep and 

 cold parts of the lake, where they spend most of their time. In the autumn 

 they again move In tow^ards the shore, seeking their spawning grounds; 

 these are chiefly rocky reefs and shoals, composed of what is known as 

 honeycomb rock. It is said that gravelly and sandy shoals are sometimes 

 resorted to for spawning purposes, but this is doubtful. 



Spawning takes place in October and November and may possibly be 

 extended by some few individuals, or under exceptional circumstances, 

 into December ; both the time of spawning and of incubation depend 

 largely upon the temperature. 



The autumn movement commences in September, but does not 

 become general until October ; the fish then continue to run in greater or 

 less numbers until the spawning is ended, when they again retire to deep 

 water for the winter. It is a curious fact that even during the spawming 

 season a large number of Whitefish are always to be found in the deep 

 water, but there is no evidence that they ever spawn there. 



(65) Sault Whitefish. 



(Coregonus labradoricus.) 



Head, five; depth, three and a half to four; eye large. Gill rakers 

 short, about two to two and a half in eye, 10+15 *^'' ^^ 



Body rather elongate, compressed, the back not elevated. Head 

 rather small, slender, compressed. Mouth rather small, the lower jaw 

 short, snout projecting ; the maxillary reaching front of pupil ; maxillary 



