566 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



WEIGHT IN OUNCES 



2 3 4 5 6 7 8 9 10 II 12 



220 



200 



t r 



1 r 



1 r 



t r 



MALES and FEMALES 



T-*— I I — I 



40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 



WEIGHT IN GRAMS 



Figure 4. — Weight-frequenoy distribution of adult sea lampreys taken in 1951. 



season only the small newly transformed lampreys 

 were found in the lake. 



Parasitic-phase sea lampreys taken from Cayuga 

 Lake show the same trend of growth as 

 Lake Huron and Lake Michigan specimens (table 

 3). These lampreys were captured during the gill- 

 netting of lake trout in 1948-51. Some lampreys 

 were entangled in the net and others adhered to 

 the netted trout. Since both large and small lam- 

 preys are caught by this method, these specimens 

 are considered to be representative of the popula- 

 tion. Lampreys captured during the several years 

 have been combined because of the small number 

 taken in any one season. 



The mean length of parasitic-phase sea lampreys 

 in Cayuga Lake increased from 5.5 inches in March 



to 15.4 inches in April-May, 13 to 14 months 

 later (table 3). Data given here include adequate 



Table 3. — Lengths of parasitic-phase sea lampreys from 

 Cayuga Lake 



Month of 

 capture 



August-Maroh >. 



April 



May 



June 



July 



August 



September 



October 



November 



January 



April-May ' 



Number of 

 specimens 



Length (Inches) 



Mean 



Minimum Maximum 



i Recently transformed lampreys captured In Cayuga Inlet. 



» Mature lampreys captured on their spawning migration In Cayuga inlet. 



