AGE DETERMINATION FROM SCALES OF LAKE TROUT 



51 



I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 



MJ JASONDJFMAMJJ ASONDJ FMAMJ JASONDJ FMAMJJASO 



n m EZ ¥ 



AGE GROUP 



Fir.iRE 27. 



-Mean length? and mean weights of tlie marked lake trout at time of capture. Year classes 1944-4fi com- 

 bined. [Curves drawn by inspection.) 



The average lengths of lake trout of the 1944-46 

 year classes of the same age group were originally 

 tahulated by semimonthly periods, but as division 

 of the data into shorter time intervals did not 

 provide additional information, the averages of 

 table 26 (see also fig. 27) were based on monthly 

 groupings. Altliough the month-to-month changes 

 in the average lengths of the age groups were de- 

 cidedly irregular, the figures do give the general 

 impression that much of the increase in length 

 took place in the late summer and fall. In other 

 words, rapid growth seems to have started about 

 the end of June and to have continued at least 

 through October, possibly longer. The records 

 of average weight of the age groups at capture 

 support a similar interpretation (table 27, fig. 27). 



T.\Bi.E 26. — Average lengths (inches) of marked lake trout 

 at time of capture 



(Data for 1944, 1945, and 1940 year classes combined.' Number of specimens 

 in parentheses] 



.lanuary 

 February 



March 



April 



May 



June.- , 



July 



.\ugust .. 

 September- 

 October 



November. 

 December-. 



Mean length.. 



Age group 



8.0 (1) 



8.5 (3) 



9.8 C4) 



9.7 (5) 



9.8 (12) 



9.9 (7) 



III 



11.5 (7) 



10.0 (39) 



15.4 (1) 

 9.9 (1) 



12.0 (2) 



11.6 (8) 



11.8 (22) 



11.9 (36) 



12.7 (30) 

 12.9 (64) 



13.5 (72) 

 11.9 (7) 

 12.4 (8) 



14.1 (4) 



IV 



13.8 (27) 

 14.6 (13) 

 14.1 (17) 



14.9 (80) 

 13.9 (156) 

 13.9 (120) 

 14.0 (183) 



14.8 (109) 

 1.^3 (13) 



15.9 (6) 

 15.6 (4) 

 15.0 (4) 



12.8 (255) 14.3 (732) 



15.0 (24) 



15.2 (6) 



16.3 (5) 



15.7 (24) 



15.8 (81) 

 15.8 (6(1) 

 16.7 (34) 

 17.6 (33) 

 16.0 (12) 



13.1 (1) 



15.8 (280) 



I Lengths of the 13 fish in age-group VI omitted because the data arc too 



scattered to be of value in this table. 



