TWENTY-SECOND ANNUAL EASTERN FISH HEALTH WORKSHOP ROYAL PAVILLION RESORT, ATLANTIC BEACH, NC MARCH 18 - 20, 1997 Sampling the Bacterial Flora of Freshwater Mussels from the Ohio River Clifford Starliper1, Rita Villella2, Patricia Morrison3 and Jay Mathias4 1USDI/BRD National Fish Health Research Lab, 1700 Leetown Road, Kearneysville, WV 25430; 2USDI/BRD Aquatic Ecology Lab, 1700 Leetown Road, Kearneysville, WV 25430; 3Ohio River Islands National Wildlife Refuge, PO Box 1811, Parkersburg, WV 26102; 4Freshwater Institute, PO Box 1746, Shepherdstown, WV 25443 There are 300 different species of freshwater mussels native to North America and over 70 % are categorized as endangered, threatened or of special concern. This and zebra mussel (Dreissena polymorpha) infestations, a caused the USFWS and other partners to collect and propagate native mussels in certain federal hatcheries with a goal of reintroduction into their native habitat at an appropriate future date. Thus, questions arose regarding contagion of bacterial pathogens between mussels and fish. The information presented here involves ongoing studies to answer such questions. Mussels native to the Ohio River (mile 175, Wood County, WV) were collected by brailing in November 1995, and June and September, 1996. In initial studies, we wanted to determine if (1) any salmonid pathogenic bacteria could be isolated from the mussels and (2) to evaluate the stability of their bacterial flora. Soft tissues were collected and separated into two samples, gut and all other tissues combined as one. Tissue samples were diluted and homogenized, then used to inoculate primary isolation media. Resulting bacteria were enumerated and representative colonies subcultured for identification. The distribution of bacteria was somewhat equal between gut and all other tissues combined. Total bacterial counts remained relatively stable over time. Of 1153 bacteria isolated, motile Aeromonas spp. (26%) and the nonfermenter group (46%) were predominant. Flavobacterium columnare was isolated from one mussel in June 1996. Return to 22nd Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page