21426342
not annotated - annotated - LINNAEUS only
Introduced brown trout alter native acanthocephalan infections in native fish.
1. Native parasite acquisition provides introduced species with the potential to modify native host-parasite dynamics by acting as parasite reservoirs (with the 'spillback' of infection increasing the parasite burdens of native hosts) or sinks (with the 'dilution' of infection decreasing the parasite burdens of native hosts) of infection. 2. In New Zealand, negative correlations between the presence of introduced brown trout (Salmo trutta) and native parasite burdens of the native roundhead galaxias (Galaxias anomalus) have been observed, suggesting that parasite dilution is occurring. 3. We used a multiple-scale approach combining field observations, experimental infections and dynamic population modelling to investigate whether native Acanthocephalus galaxii acquisition by brown trout alters host-parasite dynamics in native roundhead galaxias. 4. Field observations demonstrated higher infection intensity in introduced trout than in native galaxias, but only small, immature A. galaxii were present in trout. Experimental infections also demonstrated that A. galaxii does not mature in trout, although parasite establishment and initial growth were similar in the two hosts. Taken together, these results support the hypothesis that trout may serve as an infection sink for the native parasite. 5. However, dynamic population modelling predicts that A. galaxii infections in native galaxias should at most only be slightly reduced by dilution in the presence of trout. Rather, model exploration indicates parasite densities in galaxias are highly sensitive to galaxias predation on infected amphipods, and to relative abundances of galaxias and trout. Hence, trout presence may instead reduce parasite burdens in galaxias by either reducing galaxias density or by altering galaxias foraging behaviour.
Ann file
T1 Species 11 22 brown trout
N1 Reference T1 Taxonomy:8032
T2 Species 497 508 brown trout
N2 Reference T2 Taxonomy:8032
T3 Species 510 522 Salmo trutta
N3 Reference T3 Taxonomy:8032
T4 Species 566 584 roundhead galaxias
N4 Reference T4 Taxonomy:126302
T5 Species 586 603 Galaxias anomalus
N5 Reference T5 Taxonomy:126302
T6 Species 866 877 brown trout
N6 Reference T6 Taxonomy:8032
T7 Species 918 936 roundhead galaxias
N7 Reference T7 Taxonomy:126302
T8 Species 1035 1043 galaxias
N8 Reference T8 Taxonomy:126302
T9 Species 1097 1102 trout
N9 Reference T9 Taxonomy:8032
T10 Species 1181 1186 trout
N10 Reference T10 Taxonomy:8032
T11 Species 1328 1333 trout
N11 Reference T11 Taxonomy:8032
T12 Species 1477 1485 galaxias
N12 Reference T12 Taxonomy:126302
T13 Species 1557 1562 trout
N13 Reference T13 Taxonomy:8032
T14 Species 1622 1630 galaxias
N14 Reference T14 Taxonomy:126302
T15 Species 1655 1663 galaxias
N15 Reference T15 Taxonomy:126302
T16 Species 1727 1735 galaxias
N16 Reference T16 Taxonomy:126302
T17 Species 1740 1745 trout
N17 Reference T17 Taxonomy:8032
T18 Species 1754 1759 trout
N18 Reference T18 Taxonomy:8032
T19 Species 1808 1816 galaxias
N19 Reference T19 Taxonomy:126302
T20 Species 1836 1844 galaxias
N20 Reference T20 Taxonomy:126302
T21 Species 1868 1876 galaxias
N21 Reference T21 Taxonomy:126302
T22 Species 827 850 Acanthocephalus galaxii
#1 AnnotatorNotes T8 TODO check
T23 Species 1070 1080 A. galaxii
T24 Species 1151 1161 A. galaxii
T25 Species 1445 1455 A. galaxii
T26 Species 1014 1019 trout
N22 Reference T26 Taxonomy:8032