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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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Gut contents of Neogobius melanostomus.Relative compositions (index of relative importance, IRI) of gut contents of N. melanostomus in two rivers from June until October 2011 as well as the total mean. Bar plot, from bottom to top: Amphipoda (black), Mollusca (medium grey), Insecta (light grey), others (dark grey).
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pone-0109971-g002: Gut contents of Neogobius melanostomus.Relative compositions (index of relative importance, IRI) of gut contents of N. melanostomus in two rivers from June until October 2011 as well as the total mean. Bar plot, from bottom to top: Amphipoda (black), Mollusca (medium grey), Insecta (light grey), others (dark grey).

Mentions: 18 (Rhine) and 16 (Main) different prey items were identified in N. melanostomus guts (Table S3, Table S4). The index of relative importance (IRI) found amphipods to be the main diet component of N. melanostomus, with an overall contribution of 71% in the Rhine and 46% in the Main (Figure 2). In the Rhine, amphipods contributed with at least 30% in each monthly sample (Figure 2). The second most important group was molluscs, which contributed with 7–38% to the overall gut content. The widespread and common species Bithynia tentaculata, Potamopyrgus antipodarum and P. antipodarum f. carinata were distinguishable, but, due to a high degree of fragmentation, were combined into ‘Gastropoda indet.’. Insects were rarely consumed, except for July where the IRI for Chironomidae rose to 2,288.83 (Table S3) when very little gut content was found overall. In the Main, highest proportions of amphipods (over 80%) occurred in September and October (Figure 2). Insects were consumed more often than in the Rhine, especially in June (79%) and August (36%). Fish diet was based on molluscs with 50% and 45% in July and August, respectively. Fishes, plants and Acari were rarely consumed in both rivers.


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)

Gut contents of Neogobius melanostomus.Relative compositions (index of relative importance, IRI) of gut contents of N. melanostomus in two rivers from June until October 2011 as well as the total mean. Bar plot, from bottom to top: Amphipoda (black), Mollusca (medium grey), Insecta (light grey), others (dark grey).
© Copyright Policy
Related In: Results  -  Collection

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

pone-0109971-g002: Gut contents of Neogobius melanostomus.Relative compositions (index of relative importance, IRI) of gut contents of N. melanostomus in two rivers from June until October 2011 as well as the total mean. Bar plot, from bottom to top: Amphipoda (black), Mollusca (medium grey), Insecta (light grey), others (dark grey).
Mentions: 18 (Rhine) and 16 (Main) different prey items were identified in N. melanostomus guts (Table S3, Table S4). The index of relative importance (IRI) found amphipods to be the main diet component of N. melanostomus, with an overall contribution of 71% in the Rhine and 46% in the Main (Figure 2). In the Rhine, amphipods contributed with at least 30% in each monthly sample (Figure 2). The second most important group was molluscs, which contributed with 7–38% to the overall gut content. The widespread and common species Bithynia tentaculata, Potamopyrgus antipodarum and P. antipodarum f. carinata were distinguishable, but, due to a high degree of fragmentation, were combined into ‘Gastropoda indet.’. Insects were rarely consumed, except for July where the IRI for Chironomidae rose to 2,288.83 (Table S3) when very little gut content was found overall. In the Main, highest proportions of amphipods (over 80%) occurred in September and October (Figure 2). Insects were consumed more often than in the Rhine, especially in June (79%) and August (36%). Fish diet was based on molluscs with 50% and 45% in July and August, respectively. Fishes, plants and Acari were rarely consumed in both rivers.

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