Long-term changes in the distribution of leeches along the Danube in Hungary

Summary

The Hirudinea fauna of the Hungarian Danube section has been investigated. From a comparison with Soós's survey six new species' (G. paludosa, G. verrucata, G. concolor, H. medicinalis, E. testacea, T. bykowskii) presence were proved. Trochaeta bykowskii enlarged its distribution area considerably. The relative abundance of the species also changed though E. octoculata, D. lineata and G. complanata remained predominant.

The colonization of newly excavated catch drains in the Szigetköz area turned out to be very slow in spite of the regular connection with the side arm system around them.