Using definitive host faeces to infect experimental intermediate host populations: waterfowl hosts for New Zealand trematodes

摘要

We used a non-destructive method to identify important definitive host species in the complex life cycles for two groups of digenetic trematodes (Microphallus sp. and Notocotylus spp.). Specifically, we exposed experimental populations of the intermediate snail host Potamopyrgus antipodarum to faeces collected from New Zealand waterfowl. We found that most infections were produced when the snails were exposed to faeces from Mallard (Anas platyrhynchos), Grey Duck (A. superciliosa), Mallard - Grey duck hybrids, or New Zealand Scaup (Aythya novaeseelandiae). In addition, the parasite communities clustered into three distinct groups in multivariate space: (1) control populations and snail populations that were exposed to faeces collected from Paradise Shelduck Tadoma varigata and Black Swan (Cygnus atratus), (2) snail populations that developed mostly Microphallus sp. infections and that were exposed to scaup, Mallard, or Grey Duck faeces, and (3) snail populations exposed to scaup faeces, which developed mostly Notocotylus spp. infections. These results suggest that Mallard, Grey Duck, and scaup are functionally relevant to the life cycles of both Microphallus sp. and Notocotylus spp.