414 



BULLETIN OF THE BUREAU OF FISHERIES 



differences concern proportions that usually are affected by growth, and as of the 

 two groups that of Lake Ontario contains the largest individuals, it would appear 

 that the differences must lose in significance. The removal of the larger fish from 

 the Ontario group reduces the disparity between the H/E figures for the two groups 

 but alters little the L/H relations. (See section on "Size variations.") 



While most of the individuals of the species taken in Lake Ontario have been 

 of about the same size as those taken in Lake Michigan, a few exceptionally large 

 examples have been taken. The largest of these measures 295 millimeters. These 

 larger fish are usually conspicuously deeper than the smaller ones, and the anterior 

 dorsal profile is not gradual, but the line rises rather rapidly for half the distance 

 from the occiput to the dorsal and continues to the dorsal with only a slight upward 

 trend. 



The color of living specimens is like that of the chub and other Great Lakes 

 Leucichthys. The underlying color of the back is usually pale pea green to blue green, 

 though occasional individuals show bright tones. The iridescence is usually pinkish. 

 In spirits specimens show, on the average, less pigmentation than the paratypes. 

 The anal and ventrals are always immaculate, and the black of the snout and man- 

 dible is somewhat reduced. 



The males and at least some females develop pearl organs during the breeding 

 season. Among the specimens preserved, however, there are none that have retained 

 more than traces here and there of the breeding adornment. 



VARIATIONS 



Racial variations. — Too few specimens have been obtained from any locality 

 to permit extensive comparisons to ascertain whether there are racial differences 

 within the species. 



Size variations. — Only two specimens smaller than 200 millimeters have been 

 seen, hence it is not possible to make the usual comparisons between small and large 

 fish. The collected specimens may be divided, however, according as they are more 

 or less than 250 millimeters in length, and some indication may be derived of the 

 effect of growth on the systematic characters usually employed. Such a division 

 leaves for comparison a group of 32 specimens 250 millimeters or more in length and 

 a group of 44 smaller ones. The only marked difference between the characters of 

 the two groups is in the H/E ratio — the larger fish have a proportionally smaller eye. 

 The range of H/E for the small fish is 4-4.4 (4.5); for the larger ones (4) 4.2-4.6 (5). 



COMPARISONS 77 



Reighardi is easily distinguishable from the other species in the lake on account 

 of the fewer gill rakers on the first branchial arch and the shorter paired fins. A 

 comparison of these characters follows: 



Gill rakers on the first branchial arch: 



reighardi, (33) 35-38 (42), with 4 per cent more than 40. 

 hoyi, (39) 42-47 (50), with 98 per cent more than 40. 

 kiyi, (41) 43-46 (48). 

 artedi, (41) 46-50 (54). 



77 Figures in this section are given for all collected specimens. 



