Substrate preference in settling zebra mussels Dreissena polymorpha
Czarnołeski, Marcin; Michalczyk, Łukasz; Pajdak-Stós, Agnieszka
published: Mar 5, 2004
ArtNo. ESP141015972006, Price: 29.00 €
In a field experiment we compared recruitment of zebra mussels on two types of substrate surface, one flat and the other complex, imitating the heterogeneity of the surface between aggregated mussels. Concrete blocks, each presenting both types of substrate, were suspended horizontally or vertically in the water column along a lake shore. The density of recruits varied from 0 to 1.5 individuals/cm2 across 92 experimental substrates. Density was not affected by substrate orientation; it was significantly higher on complex than on flat substrates (median 0.32 vs. 0.18 mussels/ cm2). This indicates that besides the commonly suggested chemical cues, the complicated surface of mussel aggregates itself may elicit settling on conspecifics. We stress that gregariousness in Dreissena polymorpha may be an evolved antipredation strategy rather than a result of hyperproduction of larvae competing for scarce substrates.