386 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 3 



"scaled" during the fish census of June 

 24-28, 1941, table 12, indicate that these 

 fish reached legal length (10 inches) dur- 

 ing the second summer of life and contin- 

 ued to grow rapidly throughout their 

 life span. Fig. 2 shows a growth curve of 

 Onized Lake largemouth bass, based on 



calculated lengths from scale measure- 

 ments, with a similar growth curve for 

 the bass in Sportsmen's Lake, a small sec- 

 tion of the gravel pit lakes near Lincoln, 

 Illinois (Thompson & Bennett 1939). 



At the time of the poison census of 

 Sportsmen's Lake, May 20, 1938, that 



Table 11. — Age-length frequencies of the 275 largemouth bass collected from Onized Lake 

 in the census of June 24-28, 1941. The census was made about l'/^ months after the spawning 

 season, and the lengths shown for each age include the growth increment for the early part of 

 the 1941 season. 



