SEA LAMPREY OF CAYUGA LAKE 



597 



Table 35. — Length-frequency distribution of ammocoetes and 

 transforming sea lampreys collected in Cayuga Inlet during 

 July and August 



[The lengths are grouped by 5-mm. intervals] 



July collections from Cayuga Inlet, is also sup- 

 ported by data presented by Applegate (1950), 

 who demonstrated that in Michigan the group 

 had a mean length of 0.63 inch and age group I 

 had a length of 1.77 inches. It seems reasonable 

 to assume, therefore, that the mode at 2.24 inches 

 in figure 17 represents age-group II. It follows 

 then, that modes at lengths of 3.23, 4.21 (corrected 

 from the asymmetrical mode at 4.41) 4.80, and 

 5.51 inches represent age groups III through VI. 

 Transforming ammocoetes (VII group) form a 

 mode at approximately 5.51 inches. 



Grouping of the July and August catches of 

 ammocoetes and transforming sea lampreys re- 

 sulted in a somewhat smoother length-frequency 

 distribution (cols. 7, 8, table 35; fig. 18). Distinct 

 modes at 0.47, 1.46, 2.36 (corrected from minor 

 modes at 2.05 and 2.64), 3.23, 4.21, 5, and 5.59 

 inches represent age groups through VI. The 

 transforming lampreys form a nearly normal dis- 

 tribution with a modal length of 5.39 inches (age 

 group VII). 



Weights as well as lengths are available for 

 ammocoetes and transforming sea lampreys col- 

 lected from Cayuga Inlet during August 1951 

 (table 36; fig. 19). Six definite modes are present 



I 2 



_i_ 



TOTAL LENGTH IN INCHES 



X TRANSFORMING 



AMMOCOETES 



10 



20 30 40 50 60 70 80 90 100 110 



TOTAL LENGTH IN MILLIMETERS 



120 130 140 150 160 170 



Figure 17.— Length-frequency distribution of sea lamprey ammocoetes and transforming specimens taken from Cayuga 



Inlet during August. 



