Figure G-3. Growth curves based on the average observed size at age (Table G-7) o^Quadrula quadrula 

 collected from Reach 15 of the Upper Mississippi River in (a) 1994-95 and (b) 1987. All 

 growth curves were best described by a polynomial regression formula (Table G^). 

 Coefficient of determination (r-) values for each growth curve are listed. Minimum commercial ' 

 shell height (Illinois) and average age at sexual maturity (Table G-2) are also shown. 



8 12 16 20 24 28 32 36 



Estimated age (yrs.) 



Length (r^ = 0.9762); -o* Height (r^ = 0.9596); V Width (r^ = 0.9724) 



8 12 16 20 24 28 32 36 



Estimated age (yrs.) 



Page G-25 



Whitney et al., Unionid Suney - Reach 15 UMR 



