Invasion ecology of Echinogammarus berilloni (Crustacea, Amphipoda)

Basic data for this project

Description

Three sympatric species of Gammaridae (Amphipoda, Crustacea) show a specific spatial distribution in the upper catchment of the River Lippe, eastern Northrhine-Westphalia, Germany. The mid-stream section is characterized by temporal flow intermittency, due to karstification. Gammarus fossarum lives in the upstream reaches, whereas G. pulex prefers the mid-stream, temporary sections. Aside from these native species, Echinogammarus berilloni, a neozoon originating from the western Pyrenees, has been invading the stream system from the downstream main stem. To answer the question which factors contribute to the obvious invasion succes of this species, comparative field and laboratory experiments are conducted. Here we test the ecological valences and life traits with respect to abiotic factors, food preferences, and effect of stressors such as hydrologic perturbation and the unpredictability of environmental factors on the performance of the species. By studying the metapopulation structures, the dispersal history of the species will be traced.