of the United States Environmental Protection Agency (USEPA) at Duluth, Minnesota. One half 

 of the starter culture was placed in a 20-L aquarium containing 5 L of hard standard reconstituted 

 water and the other half of the culture was placed in a similar aquarium containing 5 L of filtered 

 creek water. These cultures were fed a 1:1 mixture of yeast-cerophyll-trout chow solution (YCT) 

 and Selenastrum capricornutum according to C. dubia (NETAC 1992a, 1992b). Culture water 

 was renewed twice weekly, and cultures were exposed to an approximate 16h:8h light:dark cycle. 



Approximately one week before testing, a styrofoam brood board was set up by removing 

 60 neonates (< 24 h) from each of the cultures and placing each one into a 30-ml plastic cup 

 containing 25 ml hard standard reconstituted water. Brood board cultures were fed 0. 1 ml YCT 

 and 0.1 ml S. capricornutum solution daily. 

 2.2.2. Tr unc ill a truncata 



Deertoe mussels, T. truncata, were collected from Reach 15 of the Mississippi River (RM 

 492.1) on December 1. 1994, and maintained in the laboratory at Forbes Biological Station. 

 Havana, IL. Tubs containing clean sand in a flowing water system (unfiltered creek water. 

 4-7°C) were used as holding containers. Mussels were fed '/: teaspoon (2.4 ml) of algal 

 suspension (Diet B. Coast Oyster Company, 12951 Del-Red Road. Suite 195, Bellevue, 

 Washington 98005-2628) every other day and exposed to an approximate 16h:8h light:dark 

 cycle. The mussels were held for one month prior to testing to acclimate them to the laboratory 

 setting. 



Mussels were acclimated to test temperature (20°C) by placing three sets of 10 mussels in 

 separate 20-L aquaria containing approximately 18 L of continuously aerated filtered creek 

 water. The aquaria were placed in an incubator where the ambient temperature was raised 3 = C 



