Parasites of two abundant sympatric rodent species in relation to host phylogeny and ecology.

In the present study, two abundant sympatric rodent species (27 Apodemus flavicollis and 33 A. sylvaticus) were studied for their endo- and ectoparasite fauna. The rodents were trapped in Dormagen, a city in North Rhine-Westphalia, Germany. A total of 20 different parasites species were identified, 13 endoparasite (2 Digenea, 5 Cestoda and 7 Nematoda) and 7 ectoparasite (5 Insecta and 2 Arachnida) species. Thirteen parasite species were found inhabiting both rodent species. The predominant endoparasite species in both rodents was the nematode Pelodera strongyloides, followed by the nematode Heligmosomoides polygyrus and a Syphacia species. The flea Ctenophthalmus agyrtes was the dominant ectoparasite in both rodent species. A. flavicollis usually carried 1-7 ecto-/endoparasite species (mean 4.0), whereas A. sylvaticus were mostly infested with 1-9 (mean 4.4). The parasite diversity of A. flavicollis (H' = 0.268, J = 0.097) was marginal lower in comparison to A. sylvaticus (H' = 0.319, J = 0.110). The two rodent species examined show remarkable similarities in the composition of their endo- and ectoparasite fauna being directly related to their similar pattern of living in the investigated area.