The use of aquatic plants by populations of the zebra mussel (Dreissena polymorpha) (Bivalvia: Dreissenidae) in a small glacial lake

摘要

We examined the early life history of the zebra mussel(Dreissena polymorpha) in a small Pennsylvania lake with lim-ited natural hard substrate. Veligers first appear in May, andsettled on Nuphar (Yellow Water Lily) stems and concrete sub-strates in equal densities. Later cohorts, however, did not settleon the stems. Juveniles on stems abruptly abandoned theirattachment in late August as the plant tissue began senescence.Aquarium experiments demonstrated that juveniles retained theability to seek and find alternate substrates even after severalmonths. Year-old zebra mussels were markedly unsuccessful incomparison. We speculate that in lakes with limited natural hardsubstrates aquatic plants may play an important role in zebramussel recruitment, although juveniles must be able to locatealternate substrates as plant populations senesce at the endof the season. The resulting high mortality may limit musselpopulations in these lakes.