Non-indigenous zooplankton − the role of predatory cladocerans and of copepods in trophic dynamics

.................................................................................................. 3 LIST OF PAPERS......................................................................................... 4 INTRODUCTION........................................................................................... 6 Biological invasions The Baltic Sea and the North American Great Lakes – invasion hot-spots OBJECTIVE OF THE THESIS.................................................................... 20 CERCOPAGIDIDS AS NON-INDIGENOUS SPECIES (Paper I & II) ....... 21 Natural distributions and invasion histories Feeding biology and ecological impacts of invasive cercopagidids Summary paper I: Review on the feeding biology of cercopagidids Background paper II: Cercopagidids as novel prey for fish and invertebrates Summary paper II: Cercopagis and food web changes in the Baltic Sea NON-INDIGENOUS COPEPODS (Paper III, IV & V)................................ 30 Invasion histories and reported impacts The role of salinity tolerance The ubiquitous calanoid Acartia tonsa Summary paper III: Salinity effects on energy balance and reproduction Summary paper IV: Effects of salinity changes on feeding and survival A case study of non-indigenous Acartia tonsa population dynamics Summary paper V: A. tonsa in the hyper-eutrophic Mariager Fjord CONCLUDING REMARKS ........................................................................ 39 LITERATURE CITED................................................................................. 40 ACKNOWLEDGEMENTS ............................................................... 52 MY CONTRIBUTION TO THE PAPERS ................................................... 53