322 



BULLETIN OF THE BUREAU OF FISHERIES. 



are really abundant, exceeding in number the males of equal age. Of the 185 6-year 

 individuals, selected without reference to sex, 79 are males and 106 females. (See Figs. 

 281 to 283.) 



Another evidence of retarded development is found in the class of 7-year fish. In 

 streams thus far studied from the Sacramento to the Fraser it is very rare for a king 

 salmon to attain the age of 7 years. Only two such specimens have been observed to 

 my knowledge. In the Yukon, however, members of this class are not uncommon. 

 Although not specially sought for, 42 are included in our series, 10 of these being males 

 and 32 females. Here, again, the late development of females compared with males 

 is made evident. (See Figs. 284 and 285.) 



Table 2 gives the distribution by sex, age, and length of all the king salmon of our 

 Yukon series of the run of 1920. For comparison similar data from a series taken from 

 the run of 19 19 by C. F. Townsend, fisheries inspector for the Bureau of Fisheries, are 

 included in this table. It should be noted that the relative size of these various classes 

 in our series does not represent their relative abundance in the run. While no selec- 

 tion was made by sex, frequent selection was made by size at critical points. Thus, 

 special attention was paid to the smaller sizes, and these appear in our series in 

 more than their normal proportions. The same is true of individuals approximating 

 30 inches in length. It was at this size that females first were found, and individuals 

 of this length were specially selected for examination. 



Table 2. — King Salmon from Mouth Yukon River, 1920 and 1919, 



Length. 



Distributed by Age and by 



1 One 3-year-old 16-inch male was discovered in 1930. No 4-ycar-old females were observed. 

 3 No 4-year-old females were found. 



