Freshwater invertebrate ecology

The research interests of the group of G. Maier focus on the ecology, behaviour and physiology of freshwater invertebrates. In particular life history strategies as well as interactions between species are the focus of attention.
Most of our investigations have been carried out with copepods and Cladocera which are important components of food webs in lakes and ponds. Currently, the mating strategies and feeding biology of copepods were studied. Important questions were whether mating in copepods is associated with increased predation risk, and - if yes - whether strategies were developed by copepods to reduce the risk of predation. Further questions concern the food requirements of nauplii which are regarded as the „bottleneck“ in copepod development, the food requirements of adult copepods and costs and benefits of the epibiosis beween the epizoic rotifer Brachionus rubens and the cladoceran Moina brachiata.
We are also interested in biodiversity research, in particular in questions concerning  “biological invasions”. Freshwater ecosystems have been invaded by a great number of non-indigenous species. The presence of “new“ species, so called “neozoans“ can have considerable effects on the native fauna. Sometimes species introduction/invasion can result in the displacement of native species. Until now we studied predation impact of invasive freshwater jellyfish on zooplankton, predator-prey interactions between invasive and native gammarids and life histories of introduced cladocerans.
Finally, we are interested in the ecology and biology of endangered animals and the conservation of freshwater systems. Large branchiopods, for example, have become rare in central Europe. The distribution of  branchiopod species and the ecology of the anostracan Branchiopus schaefferi were studied. Many running waters in Germany were canalized. The disappearance of natural structures has considerable effects on the fauna. The macrozoobenthos of natural and canalized stretches of a running water, i.e. faunal changes along these stretches were currently studied. Further, we work on the fauna of tufa brooks. Calcareous deposits can be observed on the cuticula of arthropods which live in the upper reaches of tufa brooks. These deposits can have effects on the behaviour and ecology of animals.


Gravel pits are small, man-made lakes. Hundreds of these lakes have been dredged out along the rivers Donau and Iller. The accumulation of so many lakes provides an opportunity to study lake communities and life histories of selected species in relation to environmental variables.