The taxonomic diversity of the helminths comunity of two Akodon congeners species in Argentina

NAVONE G T; ROBLES M. R.; GALLIARI C.; NOTARNICOLA J

Mendoza

Congreso; X Internacional Mammalogical Congress; 2009

Akodon azarae and A. montensis (Rodentia, Cricetidae) are allopatric species. The former is distributed in Central and North East of Argentina inhabiting open environments (grassland); the second is restricted to the primary and secondary forest of northeastern Argentina. The helminth community of A. azarae is well known, but that from A. montensis is poorly study. The aim of this work is to compare the richness (S) of helminthes present in these congener hosts along their geonemy in Argentina, determining if the presence of each taxa could be related to phylogenetic or ecological process. A. azarae (n=98), collected from 12 localities distributed from Buenos Aires to Misiones showed a richness of 13, while A. montensis, collected from 5 localities in Misiones (n=177) S was 9. The curves of accumulation of parasite species are close to reach the asymptote in both host species. This means that the observed richness is similar to the expected one. However, the curve from A. azarae indicates that fewer host specimens are necessary to reach the expected richness than in A. montensis. The Jaccard coefficient showed low specific similarity between the two parasite component communities (0.1) because of rodents does not share parasites species; however, they share four genera. As Akodon species are close related, the presence of these congener helminthes indicates possible co-speciation process due to an environmental barrier interrupting the gene flow between the hosts and their parasites. Those taxa presents in A. azarae but not in A. montensis, such as the Physalopteridae, Rictularidae, and trematodes are explained by ecological factors related to the host diet and behaviors, survivor of the free living stages of parasites in the environment and/or the presence of intermediate hosts.