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

Abstract

We examined the early life history of the zebra mussel (Dreissena polymorpha) in a small Pennsylvania lake with limited natural hard substrate. Veligers first appear in May, and settled on Nuphar (Yellow Water Lily) stems and concrete substrates in equal densities. Later cohorts, however, did not settle on the stems. Juveniles on stems abruptly abandoned their attachment in late August as the plant tissue began senescence. Aquarium experiments demonstrated that juveniles retained the ability to seek and find alternate substrates even after several months. Year-old zebra mussels were markedly unsuccessful in comparison. We speculate that in lakes with limited natural hard substrates aquatic plants may play an important role in zebra mussel recruitment, although juveniles must be able to locate alternate substrates as plant populations senesce at the end of the season. The resulting high mortality may limit mussel populations in these lakes.