Figure E-2. Frequency histograms of density (no./m-) at age for selected unionid species from Sylvan 

 Slough (RM 485.8) in Reach 15 of the Upper Mississippi River, 1987. Unionidswere 

 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 



1.0 

 0.8 

 0.6 

 0.4 

 0.2 

 0.0 



6.0 

 4.0 

 2.0 

 0.0 

 0.4 

 0.3 

 0.2 

 0.1 

 0.0 

 0.8 

 0.6 

 0.4 

 0.2 

 0.0 



6.0 

 4.0 

 2.0 



0.0 

 1.0 

 0.8 

 0.6 

 0.4 

 0.2 

 0.0 

 1.0 

 0.8 

 0.6 

 0.4 

 0.2 

 0.0 



mn 



n n 



oDD 



Amblenta plicata 

 x=6.5/m^ 



mm 



■ m ■- 



n 



Alegalonaias nervosa 

 x=14.5/m^ 



a___ 



■ n Rn nm 



Quadrula quadrula 

 x=1.3/m^ 



a 



I I 



t 



n 



nl \M In 



Quadrula nteUiitevra 

 3f=9.0/m' 



n 





nnnnnR 



mmm m 



m\ in 



Dt 



Qu a dm la pustii losa 



DmE 



on 



n 



Ellipsaria Uneolata 

 x=6.1/ni^ 



nn 



nDlt 



Ohliquaria reflexa 

 x=4.9/ni^ 



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



Estimated Age (years) 

 Page E-5 



Whitney et al., Unionid Survey - Reach 1 5 UMR 



