The co-existence of Unionidae and Dreissenidae in water reservoirs and water streams in Ukraine
L. Yanovych*, M. Pampura
Ivan Franko Zhytomyr State University
40, V. Berdychivska St., Zhytomyr 10008, Ukraine
With the purpose of research of joint existence of dreissena and unionids more than 270 points within all river basins are researched. The occurrence of Dreissena polymorpha and D. bugensis is established to be 21,7 and 7,2% correspondingly. Unionidae family mollusks and Dreissenidae often co-exist in water reservoirs and water streams. In 72,9% points of collection the number of dreissenae-epibionts on the shells of the unionid-carriers does not exceed 10 specimens per shell, in the rest it reaches 80 specimens per shell. The number of unionids with mollusks-epibionts D. polymorpha and D. bugensis at the depth of 2 m varies from 2.5 to 85% (reaching 100% in water-reservoirs). In any case the mass of overgrowth does not exceed the mass the carriers. The dreissenae donít bring species impoverishment in malacocoenosis and the Unionidae disappearance in places of co-existence.
Keywords: Dreissena polymorpha, D. bugensis, Unionidae, becoming overgrown with, co-existence