E-4. Frequency histograms of density (no./m=) at age for selected unionid species from Case-IH 

 (RM 488.5) in Reach 15 of the Upper Mississippi River, 1987. Unionids were collected 

 from 8 quantitative samples covering a surface area of 8 m-. 



Estimated Age (years) 



1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 



6.0 

 5.0 

 4.0 i 

 3.0- 

 2.0- 

 1.0 

 0.0 

 0.4 

 0.3 

 0.2 

 0.1 

 0.0 

 1.6 

 1.2 

 0.8 

 0.4 

 0.0 

 0.4 

 0.3 

 0.2 

 0.1 

 0.0 

 25.0 

 20.0 

 15.0 

 10.0 

 5.0 

 0.0 

 5.0 

 4.0 

 3.0 

 2.0 

 1.0 

 



4.0 

 3.0 

 2.0 

 1.0 

 0.0 



nnO 



Amhlema plicata 

 x=40.6/m^ 



nn^nrn^n^nni 11 Innnnnnn 



Megalonaias nervosa 

 x=1.9/m^ 



fl 



□on 



iH 



w 



Quadrula quadrula 

 x=5.5/m^ 



nnr-^nr-. 



r^rnPHri 



Quadrula metanevra 

 x=0.9/m^ 



rLDfl 



n n 



mMk 



Quadrula pustulosa 

 x=61.1/m^ 



O 



D 



Ellipsaria lineolata 

 x=32.8/m^ 



[jnrTinnnririnnn 



J 



Obllquaria reflexa 

 x=14.4/m^ 



m 



OIL 



3 5 7 9 11 13 15 17 19 21 23 25 27 29 



Estimated Age (years) 

 Page E-10 



Whitney et al , Unionid Survey - Reach 1 5 UMR 



