Changes in the feeding behaviour of benthic invertebrates: effect of the introduced polychaete Marenzelleria viridis on the Baltic clam Macoma balthica.

The exploited feeding areas of Macoma baithica and Marenzeiieria viridis were experimentally quantified in laboratory conditions. Our feeding trials showed that M. baithica was able to feed at a much wider surface area than M. viridis. Moreover, in the presence of M. i'iridis the feeding area of M. baithica and its cumulative increase in time were significantly higher than with- out the polychaete. These results suggest that M. baithica is superior to M. viridis in terms of feeding. The experiment supports the earlier findings that the presence of M. baithica appears to be a key factor limiting the further expansion of M. viridis in the northern Baltic Sea. [ABSTRACT FROM AUTHOR]