The Parasites of the Muskrat (Ondatra zibethica L.) in the British Isles

Abstract

Of the five species of helminths of the British muskrat (Ondatra zibethica L.), two (Notocotylus quinqueserialis and Hymenolepis evaginata) have been introduced with the animal. The three other species of helminths (Capillaria hepatica, Taenia taeniaeformis larva and T. tenuicollis larva) have probably been largely re-acquired from the local fauna. All of the three common species of ectoparasites [Laelaps multispinosus (Tetragonyssus spiniger), Listrophorus validus and Dermacarus n.sp.] occur in North America. Three other species (Tyroglyphus sp., Myobia n.sp., Polyplax sp.) have occurred as single individuals, the last species having probably been acquired from the water vole. Introduction into Britain has greatly depleted the original helminth fauna as regards number of species and individuals; but not so with the ectoparasites. Lists of the parasites hitherto recorded from the muskrat are given and those found in brown rats (Rattus norvegicus Erx.) and water voles (Arvicola amphibius amphibius L.).