Settlement pattern of the zebra mussel, Dreissena polymorpha, as a function of depth in Lake Constance

摘要: Settlement on suitable substrata under favourable environmental conditions is an important factor for a successful recruitment of adult populations Dreissena polymorpha. Therefore, the pattern settlement zebra mussel (Dreissena polymorpha) larvae at different depths was studied in Lake Constance. Maximum densities and newly settled juvenile mussels were observed 4 m depth, while only single episodes recorded greater (15 30 m). Temperature fluctuation used as surrogate parameter internal seiches. Biotic abiotic parameters subjected to principal component analysis (PCA). The tight coupling seiches, larval abundance 4-m depth vs. lack latter two variables indicated that water currents transported settling depth. Our data suggest physical factors, such boundary mixing should be considered sources variability settlement.