PUB - Publikationen an der Universität Bielefeld

Salamander larvae can impose a great impact on benthic organisms as they are keystone predators. Previous gut analysis revealed that their diet consists of invertebrates from the wa-ter column and benthic taxa. The impact on benthic communities, especially on meiofauna, is, however, not well understood yet, as these organisms cannot be detected reliably in the gut. To avoid this, we investigated the impact of fire salamander larvae on meiofauna by ana-lyzing consumed prey items from a microcosm. Fire salamander larvae can be found in dif-ferent habitats, such as streams and ponds. To test the impact of fire salamander larvae on the meiofauna and to test whether the effects differ in larvae from different habitats, we col-lected 20 larvae from both, ponds and streams from the wild and transferred them to the lab. We placed each larva individually into a microcosm with sediment and benthic organisms. We also added control samples without larvae. We kept the larvae either for one week or two weeks and counted the number of nematodes, oligochaetes and rotifers after we removed the larvae. Fire salamander larvae significantly reduced the meiofauna. Furthermore, fire salamander larvae show habitat specific differences, as nematodes were influenced more strongly by pond larvae during the first week. Oligochaetes were mainly influenced by stream larvae, but not by pond larvae, independent of the duration of the experiment. Rotifers were influenced by larvae from both habitats, but only during the first week and not during the second week. Our findings suggest that fire salamander larvae are able to reduce the meiofauna through predation. Furthermore, our finding indicates an adaptation towards the different environmen-tal conditions in the habitat of origin.