10.5061/DRYAD.C5M0R
Beggel, Sebastian
Brandner, Joerg
Wasserwirtschaftsamt Regensburg, Regensburg, Germany
Cerwenka, Alexander F.
Ludwig Maximilian University of Munich
Geist, Juergen
Ludwig Maximilian University of Munich
Data from: Synergistic impacts by an invasive amphipod and an invasive
fish explain native gammarid extinction
Dryad
dataset
2016
Neogobius melanostomus
Dikerogammarus villosus
anti-predator behaviour
Gammarus pulex
species displacement
selective predation
2016-07-07T14:21:23Z
2016-07-07T14:21:23Z
en
https://doi.org/10.1186/s12898-016-0088-6
26959 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Background: Worldwide freshwater ecosystems are increasingly affected by
invasive alien species. In particular, Ponto-Caspian gobiid fishes and
amphipods are suspected to have pronounced effects on aquatic food webs.
However, there is a lack of systematic studies mechanistically testing the
potential synergistic effects of invasive species on native fauna. In this
study we investigated the interrelations between the invasive amphipod
Dikerogammarus villosus and the invasive fish species Neogobius
melanostomus in their effects on the native amphipod Gammarus pulex. We
hypothesized selective predation by the fish as a driver for displacement
of native species resulting in potential extinction of G. pulex. The
survival of G. pulex in the presence of N. melanostomus in relation to the
presence of D. villosus and availability of shelter was analyzed in the
context of behavioural differences between the amphipod species. Results:
Gammarus pulex had a significantly higher susceptibility to predation by
N. melanostomus compared to D. villosus in all experiments, suggesting
preferential predation by this fish on native gammarids. Furthermore, the
presence of D. villosus significantly increased the vulnerability of G.
pulex to fish predation. Habitat structure was an important factor for
swimming activity of amphipods and their mortality, resulting in a
threefold decrease in amphipods consumed with shelter habitat structures
provided. Behavioral differences in swimming activity were additionally
responsible for higher predation rates on G. pulex. Intraguild predation
could be neglected within short experimental durations. Conclusions: The
results of this study provide evidence for synergistic effects of the two
invasive Ponto-Caspian species on the native amphipod as an underlying
process of species displacements during invasion processes. Prey behaviour
and monotonous habitat structures additionally contribute to the decline
of the native gammarid fauna in the upper Danube River and elsewhere.
raw-data for Synergistic impacts by an invasive amphipod and an invasive
fish explain native gammarid extinctionExcel file. Data collected in
laboratory experiments. Tab 1: Mortality data [%] (1=size class small,
2=size class big); Tab 2: Predation data [total number]; Tab 3: Swimming
behaviour [number of free swimming gammarids] (T1-T5: Replicate
tanks).raw-data.xlsx
Danube