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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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Amphipod prey and infections with Pomphorhynchus sp.Relationship between numerical percentages of D. villosus (grey) and Amphipoda indet. (white) in the gut content of N. melanostomus and mean intensities (mI, black line) of Pomphorhynchus sp. in male (grey dashed line) and female (black dashed line) N. melanostomus. For numbers of individuals please refer to Table S3 and Table S4.
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pone-0109971-g004: Amphipod prey and infections with Pomphorhynchus sp.Relationship between numerical percentages of D. villosus (grey) and Amphipoda indet. (white) in the gut content of N. melanostomus and mean intensities (mI, black line) of Pomphorhynchus sp. in male (grey dashed line) and female (black dashed line) N. melanostomus. For numbers of individuals please refer to Table S3 and Table S4.

Mentions: The most prevalent metazoan parasite type was Pomphorhynchus sp. with 100% prevalence in August and September in fish caught in the Rhine (Table 4). Maximum intensity reached 118 specimens per fish. Highest prevalence of Pomphorhynchus sp. in the Main was recorded in June with 74.3%. Mean intensity of Pomphorhynchus sp. was an order of magnitude larger in fishes sampled from the Rhine (maximum mI = 34.6) than from the Main (maximum mI = 3.48) and always greater in female than in male N. melanostomus (rmGLM, significant interaction of ‘sex × site’; Table 5; Figure 4). The nematode R. acus occurred with significantly lower prevalence in the Rhine (min. 28.57%, max. 57.14%) than in the Main (74.29% and 91.43%; Wilcoxon signed-rank test, z = –2.023, p = 0.043; Table 4). A maximum intensity of specimens of R. acus per fish was detected. Undetermined glochidia, i.e., parasitic larvae of unionid bivalves were detected on fish gills only in June (P = 54.3%) and October (P = 38.1%) in the Main.


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)

Amphipod prey and infections with Pomphorhynchus sp.Relationship between numerical percentages of D. villosus (grey) and Amphipoda indet. (white) in the gut content of N. melanostomus and mean intensities (mI, black line) of Pomphorhynchus sp. in male (grey dashed line) and female (black dashed line) N. melanostomus. For numbers of individuals please refer to Table S3 and Table S4.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0109971-g004: Amphipod prey and infections with Pomphorhynchus sp.Relationship between numerical percentages of D. villosus (grey) and Amphipoda indet. (white) in the gut content of N. melanostomus and mean intensities (mI, black line) of Pomphorhynchus sp. in male (grey dashed line) and female (black dashed line) N. melanostomus. For numbers of individuals please refer to Table S3 and Table S4.
Mentions: The most prevalent metazoan parasite type was Pomphorhynchus sp. with 100% prevalence in August and September in fish caught in the Rhine (Table 4). Maximum intensity reached 118 specimens per fish. Highest prevalence of Pomphorhynchus sp. in the Main was recorded in June with 74.3%. Mean intensity of Pomphorhynchus sp. was an order of magnitude larger in fishes sampled from the Rhine (maximum mI = 34.6) than from the Main (maximum mI = 3.48) and always greater in female than in male N. melanostomus (rmGLM, significant interaction of ‘sex × site’; Table 5; Figure 4). The nematode R. acus occurred with significantly lower prevalence in the Rhine (min. 28.57%, max. 57.14%) than in the Main (74.29% and 91.43%; Wilcoxon signed-rank test, z = –2.023, p = 0.043; Table 4). A maximum intensity of specimens of R. acus per fish was detected. Undetermined glochidia, i.e., parasitic larvae of unionid bivalves were detected on fish gills only in June (P = 54.3%) and October (P = 38.1%) in the Main.

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