GREAT LAKES COREGONIDS 



527 



leaves, while the nets at East Tawas at the entrance of the bay get them as they move 

 out; (3) at Killarney and Port Huron the fish are taken on the shoals when the ice 

 leaves, and at Blind River and Thessalon they are taken in 25 feet of water as soon 

 as the nets are put in in May. Where ice does not form regularly, the heavy winter 

 winds probably drive the fish to deeper water, as off Alpena. 



BREEDING HABITS 



The size of spawning fish varies with the locality. In general males are smaller 

 than females and mature at less size. One of the largest races in the lake is found off 

 Alpena. Here, on November 16, 1917, males were found on the spawning grounds 

 as small as 2}/2 pounds in the round, occasionally even 2 pounds, while no females 

 were seen smaller than 3 pounds. Individuals of both sexes occurred as large as 14 

 pounds, but only females over 5 pounds were relatively common. An examination 

 of the sexual condition of two lifts of whitefish taken in 43^-inch nets, numbering 

 419 individuals, off Alpena on July 3 and 10, 1923, confirmed these findings, making 

 allowance for increased weight due to growth and to development of the sex glands 

 in the four or five months' period preceding the spawning season. At that season 

 males under 2 pounds in the round usually showed no indication of spawning in the 

 fall, while females usually were not maturing under 2^ pounds. The data for all 

 these specimens of July, 1923, are given below: 



Weight in the round 



1 pound 8 ounces. .. 



1 pound 12 ounces. . 



2 pounds.. 



2 pounds 4 ounces.. 

 2 pounds 8 ounces - . 



2 pounds 12 ounces . 



3 pounds.. 



3 pounds 4 ounces.. 

 3 pounds 8 ounces.. 



Males 



Imma- 

 ture 



Matur- 

 ing 



Females 



Imma- 

 ture 



Matur- 

 ing 



Weight in the round 



3 pounds 12 ounces. 



4 pounds 



4 pounds 4 ounces. . 

 4 pounds 8 ounces. . 



4 pounds 12 ounces. 



5 pounds 



5 pounds 4 ounces.. 

 5 pounds 8 ounces.. 



Males 



Imma- 

 ture 



Matur- 

 ing 



Females 



Imma- 

 ture 



Matur- 

 ing 



The fish in Hammond Bay are said to be large also. 



The smallest breeding fish were observed in the North Channel. Whitefish 

 taken by J. H. Young off Barrie Island, on September 27, 1919, ranged from 2 to 4 

 pounds, and virtually all were mature males or females. Mr. Young assured me that 

 this catch was average and that he seldom gets fish larger than 4 pounds. At Kaga- 

 wong, on November 10, 1917, and in 1919, the fish were no larger than at Gore Bay. 

 Here pearled males less than 1J^ pounds in the round were taken occasionally. 

 Alfred Rocque and Charles Lowe, of Killarney, tell me that there is a run of these 

 small fish toward the last of November around the Cloche Islands at the eastern end 

 of the channel. They congregate around these islands to spawn and are so small that 

 many pass through the 4j^-inch gill nets that are used to catch them. In Kagawong 

 and Manitou Lakes on Manitoulin Island also the fish are said to run very small. 



The time of spawning varies with the locality. In Saginaw Bay, on October 25 

 1917, I found many of the fish ripe; some of the females were even nearly spent. 

 In the North Channel at Blind River, on November 8, 1917, Mr. Baxter told me, the 

 94995—29 16 



