324 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Number of 

 fish 



1953 



Females 



(519) 

 Males 

 (1,040) 



10 



1 1 1 1 1 1 1 1 1 rr~f f i rfT'ifTf^r i r i 



11 12 13 U 15 

 Total length in inches 



10 



11 



12 



13 



14 



15 



Total length in inches 



Figure 12. — Length-frequency diagram of Grebe Lake grayling captured during the 1953 and 1954 spawning migrations. 



Breeding 



Male grayling established territories on reaching 

 suitable spawning grounds. Such areas were de- 

 fended vigorously against other males. The terri- 

 tory varied in size with the extent of the bottom 

 available in that immediate region. In North- 



west Creek, males had territories approximately 

 6 inches wide and 2 feet long. In the outlet where 

 the stream is about 8 to 10 feet wide, they were 

 as large as 4 feet square, or approximately one-half 

 the width of the stream at that point. 



Water depth did not seem to be important in site 



