Kendall. — Blue Pike and Yellow Pike 259 



3 2-5 inches) to 600 mm. (about 23 2-5 inches), and the blue 

 pike from 280 mm. (about 11 inches) to 436 mm. (about 

 17 1-6 inches). The majority of each form in which the sex 

 could be distinguished, were either gravid females or females 

 just past the spawning season. 



The jfish were first laid out and compared as to general 

 appearance. The contrast in color was most pronounced in 

 fresh specimens. The blue pike were darker, and had no trace 

 of yellow which the yellow pike always showed as tints or 

 reflections. The fins were never yellow, while in the yellow 

 pike they were often so colored. The belly of each was al- 

 ways white, although in the larger yellow pike and a few of 

 the smaller it was sometimes tinged with yellow. Most of 

 the blue pike had ventrals and anal strongly marked with dark 

 shades or spots, in some faint, but never entirely absent. In 

 the case of most of the yellow pike, these fins were plain, but 

 in a few faintly spotted. 



Aside from color, the general appearance of the blue pike 

 suggested a more slender head, narrower interorbital width, 

 and noticeably larger eye, particularly in the smaller specimens, 

 than the yellow pike. Fin ray and scale counts, though vari- 

 able, revealed nothing distinctive. Closer inspection showed 

 that as a rule, the preopercular teeth were more numerous and 

 finer than in the yellow pike, in which the teeth were simple 

 and not bifid or trifid as in the blue pike. One specimen each 

 was skeletonized and no difference detected in the cranial 

 bones or number of vertebrae. 



Besides counting series of scales and the fin rays, various 

 measurements were taken of the head and body and reduced 

 to percentages of head or body. The percentages were then 

 tabulated in the order of the total lengths of the fish, from 

 the smallest to the largest, regardless of whether they were 

 yellow or blue pike; the two kinds were indicated by different 

 colors of ink. Thus those of similar lengths were brought in 

 juxtaposition. 



