Location: Animal Parasitic Diseases LaboratoryTitle: A widespread distribution for Arostrilepis tenuicirrosa (Eucestoda: Hymenolepididae) among arvicoline rodent hosts (Cricetidae) from the Palearctic based on molecular and morphological criteria: Historical and biogeographic Author
Submitted to: Acta Parasitologica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2013
Publication Date: 12/1/2013
Citation: Galbreath, K., Ragaliauskaite, K., Kontrimavicius, L., Makarikov, E., Hoberg, E.P. 2013. A widespread distribution for Arostrilepis tenuicirrosa (Eucestoda: Hymenolepididae) among arvicoline rodent hosts (Cricetidae) from the Palearctic based on molecular and morphological criteria: Historical and biogeographic. Acta Parasitologica. 58:441-452. Interpretive Summary: An understanding of the diversity and distribution of parasite species is essential to predicting the outcomes of environmental change. Intensive and geographically extensive surveys provide essential baseline data, but many regions remain poorly known. Recent field collections, studies of specimens held in museum archives, and molecular-based analyses have revealed insights about the distribution of tapeworms which circulate among rodent hosts across Northern latitudes. A cestode (Arostrilepis tenuicirrosa) from redbacked voles was previously reported only from the Russian Far East. Here, we provide the first records of this tapeworm in the European (western) region of the Palearctic, providing a basis for understanding other, broadly distributed tapeworms in the Holarctic as a complex of cryptic species. Minimal molecular or morphological diversity among them justify the conclusion that eastern and western populations of these parasites have not diverged much. These and related data suggested that the parasites may have expanded from East Asia during the Late Pleistocene. These studies corroborate an emerging view of how vertebrates and their parasites became established in the North, involving numerous events of geographic and host colonization from Eurasia into Europe and North America. Results of the study are important to parasitologists and disease specialists in exploring patterns of pathogen distribution and diversification in response to climate change.
Technical Abstract: Hymenolepidid cestodes in Myodes glareolus from Lithuania and additional specimens originally attributed to Arostrilepis horrida from the Republic of Belarus are now referred to A. tenuicirrosa. Our study includes the first records of A. tenuicirrosa from the European (western) region of the Palearctic, and contributes to the recognition of A. horrida (sensu lato) as a complex of cryptic species distributed broadly across the Holarctic. Specimens of A. tenuicirrosa from Lithuania were compared to cestodes representing apparently disjunct populations in the eastern Palearctic based on structural characters of adult parasites and molecular sequence data from nuclear (ITS2) and mitochondrial (cytochrome b) genes. Morphological and molecular data revealed low levels of divergence between eastern and western populations. Phylogeographic relationships among populations and host biogeographic history suggests that limited intraspecific diversity within A. tenuicirrosa may reflect a Late Pleistocene transcontinental range expansion from an East Asian point of origin.