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Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

Emde S, Kochmann J, Kuhn T, Plath M, Klimpel S - PLoS ONE (2014)

Bottom Line: However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus.Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main.Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

View Article: PubMed Central - PubMed

Affiliation: Institute for Ecology, Evolution and Diversity, Goethe-University, Frankfurt am Main, Hesse, Germany.

ABSTRACT
Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

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Dominant amphipod species.Fraction of the two dominant amphipod species (D. villosus = light grey, E. trichiatus = dark grey) in samples collected at our two study sites and numerical percentages of D. villosus in gut contents of N. melanostomus (black squares). Chi2 goodness-of-fit tests were used to compare the availability of different amphipod species on site (expected values) with observed compositions in gut contents. For total numbers of individuals and amphipod species see Table S2.
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pone-0109971-g001: Dominant amphipod species.Fraction of the two dominant amphipod species (D. villosus = light grey, E. trichiatus = dark grey) in samples collected at our two study sites and numerical percentages of D. villosus in gut contents of N. melanostomus (black squares). Chi2 goodness-of-fit tests were used to compare the availability of different amphipod species on site (expected values) with observed compositions in gut contents. For total numbers of individuals and amphipod species see Table S2.

Mentions: 717 to 3,758 amphipods were collected during the monthly samplings, with a total of n = 9,820 in the Rhine and n = 7,536 in the Main (see Table S2). Five invasive but no native amphipod species were found in both rivers, namely D. villosus, Echinogammarus trichiatus (Martynov, 1932), Echinogammarus ischnus (Stebbing, 1899), Chelicorophium curvispinum (Sars, 1895) and Chelicorophium robustum (Sars, 1895). Cryptorchestia cavimana (Heller, 1865) occurred only in samples from the Main. Dikerogammarus villosus was dominating in all samples from the Main (total n = 5,346; 69%), except for September (Figure 1). In contrast, E. trichiatus was the dominant species in all samples from the Rhine (total n = 8,463; 86%; Figure 1). In both rivers a more balanced sex ratio was found for D. villosus (males:females, Rhine: 1∶1.03; Main: 1∶1.29) than for E. trichiatus (Rhine: 1∶2.36; Main: 1∶3.10).


Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

Emde S, Kochmann J, Kuhn T, Plath M, Klimpel S - PLoS ONE (2014)

Dominant amphipod species.Fraction of the two dominant amphipod species (D. villosus = light grey, E. trichiatus = dark grey) in samples collected at our two study sites and numerical percentages of D. villosus in gut contents of N. melanostomus (black squares). Chi2 goodness-of-fit tests were used to compare the availability of different amphipod species on site (expected values) with observed compositions in gut contents. For total numbers of individuals and amphipod species see Table S2.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206283&req=5

pone-0109971-g001: Dominant amphipod species.Fraction of the two dominant amphipod species (D. villosus = light grey, E. trichiatus = dark grey) in samples collected at our two study sites and numerical percentages of D. villosus in gut contents of N. melanostomus (black squares). Chi2 goodness-of-fit tests were used to compare the availability of different amphipod species on site (expected values) with observed compositions in gut contents. For total numbers of individuals and amphipod species see Table S2.
Mentions: 717 to 3,758 amphipods were collected during the monthly samplings, with a total of n = 9,820 in the Rhine and n = 7,536 in the Main (see Table S2). Five invasive but no native amphipod species were found in both rivers, namely D. villosus, Echinogammarus trichiatus (Martynov, 1932), Echinogammarus ischnus (Stebbing, 1899), Chelicorophium curvispinum (Sars, 1895) and Chelicorophium robustum (Sars, 1895). Cryptorchestia cavimana (Heller, 1865) occurred only in samples from the Main. Dikerogammarus villosus was dominating in all samples from the Main (total n = 5,346; 69%), except for September (Figure 1). In contrast, E. trichiatus was the dominant species in all samples from the Rhine (total n = 8,463; 86%; Figure 1). In both rivers a more balanced sex ratio was found for D. villosus (males:females, Rhine: 1∶1.03; Main: 1∶1.29) than for E. trichiatus (Rhine: 1∶2.36; Main: 1∶3.10).

Bottom Line: However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus.Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main.Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

View Article: PubMed Central - PubMed

Affiliation: Institute for Ecology, Evolution and Diversity, Goethe-University, Frankfurt am Main, Hesse, Germany.

ABSTRACT
Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

Show MeSH
Related in: MedlinePlus