A Review of the Helminth Parasites of Australian Rodents

Abstract

The most recent catalogue of the internal parasites of Australian rodents is that prepared by Mackerras in 1958. She listed 89 native rats belonging to 18 genera of which 8 species had had parasites recorded from them. There has been very little progress made since that time. The most recent catalogue of Australian mammals lists 57 extant species of rodents in 14 genera. Helminths have now been reported from 16 of those species. The helminth communities occurring in only two rodent hosts, Rattus fuscipes and Hydromys chrysogaster , have been studied in detail. The contrast in helminth communities from these two hosts, one dominated by trematodes and the other by nematodes, may reflect not only differences in the ecology and geographic distribution of both host and parasite but also differences in the origins of the two subfamilies, the Hydromyinae and the Murinae, to which they belong. An analysis of the helminth communities of native rodents suggested patterns of speciation of the helminths that included co-evolution with host species-groups, and host switching from the Hydromyinae to the Murinae as well as the reverse. Species such as the cestode Hymenolepis diminuta and the nematode Heterakis spumosa may have been introduced or re-introduced by the recent arrival of cosmopolitan Rattus species, and species such as Paramelistrongylus skedastos have transferred from marsupial hosts.