Physical Fac Ors That Limit the Distribution and Abundance of Dreissena Polymorpha ( Pall . )

Dreissena po ymorpha, the zebra mussel, originated in the Caspian and Black Sea basin, and has invaded waterbodies of the Former Soviet Union FSU), eastern, and western Europe during the last 200 years. Since 1771 more than 2,000 papers on the distribution, taxonomy, biol gy, ecology, and control of species and subspecies of Dreissena were published in Russia and FSU, however. this work has not een generally available. We review work conducted in the FSU over the last 100 years on the tolerance of D. polymorpha to differe t abiotic conditions in waterbodies of various types in order to provide non-Russian-speaking scientists access to this rich body of li erature, D. polymorpha is one of the few bivalve molluscs well adapted to live from entirely fresh water to brackish waters. Differen subspecies appear to have different salinity tolerances. ranging from completely fresh water to 18.5%. Zebra mussels require at le t 25% oxygen saturation. although they can survive several days in anaerobic conditions. The quagga mussel. D. bugensis. howeve , is much more tolerant of low oxygen conditions. The upper temperature limit for zebra mussels is around 32-34°C. Zebra mussels are most abundant on hard surfaces, particularly rocky surfaces, and on macrophytes. Water motion, aerial exposure. freezing, and the ther physical factors including temperature, salinity, and oxygen affect the distribution of zebra mussels among and within waterb ies. Many of these factors are expected to covary. or differ predictably among waterbodies, driving distribution and abundance atterns as well as patterns of invasibility that we see both within and among waterbodies.