256 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



depicted in figure 8. Since these two cliaractei-s 

 are not independent they should not be used in- 

 dependently in any I'acial analysis involving a 

 "character" index. The relation between number 

 of vertebrae and number of oblique scale rows 

 (0/V in fig. 8) on the other hand shows that there 

 is a wide variation in the degree of branching of 

 the lateral-line scale papillae: malnut and fonti- 

 luilis with an O/V ratio of 3.65 and 3.74, respec- 

 tively, represent the extreme in fine scaling; 

 alpinus and nfimaycush with O/V ratios of 3.06 

 and 3.11 form another distinct group; g&riuscJia, 

 with an increase in both types of scale counts, 

 occupies a unique position. All of the species of 

 Sahno show a slight to moderate increase in the 

 number of oblique scale rows over the number of 

 lateral-line scales. 



Surprisingly, in view of the position of gor- 

 busc/ia, the other species of Oncorhynchu.s show 

 no detectable increase in number of oblique scale 

 rows over their lateral-line scale counts. 



The number of horizontal scale rows is avail- 

 able for so few species that counts for all genera 

 are combined in table 25. The data for Salmo 

 salai' and S. trutta differ in the metliod of count- 

 ing and these species cannot be compared with the 

 others. The i)ublished values of 0.82 and 0.16, 

 given presumably as standard errors of the mean 

 for salnr and tniffa, differ widely. This suggests 

 strongly that the number of specimens wliose 

 scales were counted (at least for salar) was much 

 less than the 41 given by McCrimmon (1949). It 

 is therefore doubtful whether the means for the 

 two species should be considered significantly dif- 

 ferent without additional data. 



Table 25. — Numher of horizontal scale rows in certain species of Salmonidae 



Species 



Number 



of 

 specimens 



Mean 

 number 

 of rows 



Range 



Minimum Maximum 



Total 



Percentile 



20 



80 



80-20 



Year 



Oncorkjinchus: 



gorbuscha *.. 



Do.! 



Do.! 



tshawijtscha ' 



bo.! 



Do.2 



kisiitch ' 



Do.! 



Do.! 



trtai- 



Do.2 



Do.! 



nerka ' 



Do.3 



Do.' 



Do.< 



Do.< 



Do.t 



Do.«_... 

 Salmo: 



gairdneri 2 



Salveliniis: 



malma ^ 



alpinus ^ 



Oncorhynchui: 

 gorbuscha '— 

 tshawi/tscha V 



kisutch ' 



nerka 1 



keta 1 



Salveliniis: 



malma ^ 



alpinus ^ 



Salmo: 



salar ^ 



trutta ' _. 



319 

 109 

 127 

 113 

 165 



15 

 15 



From Anterior of Dorsal Fin to Lateral Line 



From Anterior of Ventral (Pelvic) Fin to Lateral LrNE 



From Posterior Base of Adipose Fin to Lateral Line 



1946 

 1947 



1946 

 1947 



1946 

 1947 



1946 

 1947 



1946 

 1947 

 1946 

 1947 

 1946-47 

 1946-47 



1946-47 



1939-41 

 1939-41 



1939-41 

 1939-41 



' Foerster and Pritchard (1935a); Fraser River to northern British 

 Columbia. 

 ' Milne (1948); Skeena River, British Columbia. 

 ' Milne (1948); Prince Rupert, British Columbia. 

 ' Milne (1948); Moricetown. Skeena River, British Columbia. 

 « Milne (1948); Babine Lake, Skeena River, British Columbia. 

 • Milne (1948); Lakelse Lake, Skeena River, British Columbia. 



' DeLacy and Morton (1943); Karluk Lake, Alaska. 



^ Standard deviation. 



• McCrimmon (1949). 



'0 These values are presumably the standard error of the mean, but foi 

 talar the error is inexplicably large if the number of specimens is 41 as statec 

 by McCrimmon (1949, p. U). 



