208 XJ. S. BUREAU OF FISHERIES 



The situation is paralleled by several other kinds of fish; for 

 example, the "yellow pike " {Stizostedion vitrewn Mitchill) and the 

 blue pike {S. glaucvmi Hubbs), two whitefishes of northern Maine 

 {Coregonus clupeaformis Mitchill and C. Stanley i Kendall), the lar^^e 

 and " dwarf " lonjj-nosed suckers {Catostotnus m^cs^o^niis Forster and 

 C. nanoniyzon Mather), and the large and " dwarf " common sucker 

 {G. coiiiniersonii Lacepede and G. ut(m.oan<i Mather). Very probably 

 there are others that have not been recognized. The evidences of 

 divergence are : 



1. Sharply distinct range in size of adult breeding fish. 



2. Difference in spawning time. 



3. Difference in character of food (at least in one lake, where the 

 food of each class has been studied). 



4. Age of the fish, as determined by scale reading. The " small " 

 breeding smelt are 2 and 3 years old, and the " large " smelt are 3 

 years old and upward to 5 or 6 years. 



5. There are a number of small structural differences that distin- 

 guish the " small " smelt from the " large " smelt of each lake, but 

 both the large and small smelt of each lake differ somewhat from 

 those of othT'r lakes (the two size classes of only two lakes, Sebago 

 and Green, have been studied). 



In view of the foregoing facts, which are discussed in detail in the 

 report now about completed, the logical procedure in fish-cultural 

 distribution is to regard each of the two size classes as distinct species, 

 whether or not the facts and figures permit them to be regarded so 

 taxonomically. 



During the spring of 1927 collections of both large and small 

 smelt were received from Green Lake through the division of fish 

 culture. The large smelt were collected from May 8 to 11 and were 

 the last of the run. There were 275 specimens, ranging from 131 to 

 285 millimeters in total length. Of these, 49 were females ranging 

 in length from 173 to 285 millimeters and averaging 224.4 millimeters. 

 They were 3, 4, 5, and possibly 6 years old. No 2-year fish were 

 present. 



Oi the large collection of small smelt taken in the last part of April 

 and first part of May, a run of only 6 days, 1,463 individuals were 

 measured and examined. They ranged from 71 to 106 millimeters 

 in total length. There were only 94 females in the lot. The fish 

 were 2 and 3 years old. The largest 2-year-old fish was 100 milli- 

 meters and the smallest 3-year-old was 90 millimeters long. Many 

 spent fish had their stomachs gorged with smelt eggs. - 



In the spring of 1927 there was virtually no run in the brooks, 

 which for several years have been under observation during the 

 spawning run of salt-water smelt. Although the usual number of 

 boys and men were on the brooks almost every night, quite positively 

 not over 100 smelts in all were taken. 



A peculiarity of the run that did occur was the fact that most of 

 the fish, even at the beginning of the run, were large 3 and 4 year old 

 females, whereas usually the fish are comparatively small and chiefly 

 2-year-old males at the beginning of the season. This fact suggests 

 that either but few eggs of the spring of 1925 hatched or else the 

 fish did not survive. So far as the two brooks under observation are 

 concerned, the j)robability is that there was no hatch, inasmuch as 



