2004 Freshwater Mussel Survey of the Big Piney River and Roubidoux Creek, Pulaski County, Missouri

Native freshwater mussels are an ecologically important group of aquatic mollusks. This group is of particular concern to conservation biologists because many species are classified as species of conservation concern (SCC). The freshwater mussel community of the Big Piney River and Roubidoux Creek, on and in the vicinity of Fort Leonard Wood, was previously surveyed by Sternburg et al. (1998). The present project was a resurvey of the area to determine the current status of the mussel community, so that appropriate measures can be taken to preserve and protect that community

Factors Affecting Feeding and Growth of Juvenile Freshwater Mussels (Unionidae)

Survival and growth rates of caged juvenile mussels were determined at five sites along a thirty kilometer reach of the James River over a six week period in summer. The juveniles were initially 7.5 mm long. Two species were compared: a habitat generalist (Potamilus alatus) and a small stream specialist (Lampsilis reeveiana). Suspended particles in the size range of 1-10 micrometer (a measure of food availability) increased progressively from upstream to downstream. Water temperature varied among sites and was lowest at the fourth most downstream site and highest at the most downstream site. Mussels were caged with or without access to the substrate, and both upstream and downstream of structure. Growth rate (length/time) was highest at the most downstream site and was strongly correlated with temperature but not with particle concentration. Both species responded similarly, but P. alatus had higher growth than L. reeveiana at all five sites. Juveniles in contact with substrate did not grow faster than those that were not in contact, suggesting that deposited particles were not an important food source. Juveniles caged upstream of structure (a partly buried cinder block) grew more slowly and had lower survival than those caged downstream of structure