Aim: We used comparative phylogeography of two intestinal parasites of freshwater fish to test whether similarity in life cycle translates into concordant phylogeographical history. The thorny-headed worms Pomphorhynchus laevis and P. tereticollis (Acanthocephala) were formerly considered as a single species with a broad geographical and host range within the Western Palaearctic.Location: Central and eastern parts of Northern Mediterranean area, Western and Central Europe, Ponto-Caspian Europe.Methods: A mitochondrial marker (COI) was sequenced for 111 P. laevis and 50 P.tereticollis individuals and nuclear ITS1 and ITS2 sequences were obtained for 37 P. tereticollis has differentiated more recently within the Western and Central parts of Europe, and shows weak geographical and genetic structuring. Conclusion:Our study highlights weak to moderate similarity in the phylogeographical pattern of these acanthocephalan parasites compared to their amphipod and fish hosts. The observed differences in the timing of dispersion and migration routes taken may reflect the use of a range of final hosts with different ecologies and dispersal capabilities. By using a group underrepresented in phylogeographical studies, our study is a valuable contribution to revealing the biogeography of host-parasite interactions in continental freshwaters. K E Y W O R D Samphipod, British islands, comparative phylogeography, Cyprinidae, Danube, helminth, Mediterranean, Messinian salinity crisis, Pomphorhynchus, Ponto-Caspian

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Complete sequences of ribosomal and mitochondrial genes of the giant liver fluke Fascioloides magna are presented. In particular, small subunit (18S) and internal transcribed spacers (ITS1 and ITS2) of the ribosomal gene (rDNA), as well as cytochrome c oxidase subunit I (cox1) and nicotinamide dehydrogenase subunit I (nad1) of the mitochondrial DNA (mtDNA), were analyzed. The 18S and ITS sequences were compared with previously published sequences of the liver fluke Fasciola hepatica. Fixed interspecific genetic differences were determined that allow molecular differentiation of F. magna and F. hepatica using either the PCR-RFLP method or PCR amplification of species-specific DNA regions. Additionally, intraspecific sequence polymorphism of the complete cox1 and nad1 mitochondrial genes in geographically distinct F. magna populations was determined. Based on the sequence divergences, short (< 500 bp) variable regions suitable for broader biogeographical studies of giant liver fluke were designed.

Pomphorhynchus tereticollis (Rudolphi, 1809) is here redescribed on the basis of Rudolphi’s material, deposited in the Museum für Naturkunde Berlin, and on acanthocephalans recently collected from the type host Platichthys flessus (L.) and the region embodying the type locality. Out of the paratypes of P. tereticollis, the lectotype and paralectotypes have been designated. Their morphology fits well with that of newly collected material of P. tereticollis dissected from the type fish host from the Baltic coast near Stralsund. The resurrection of P. tereticollis, previously considered a synonym of Pomphorhynchus laevis (Zoega in Müller, 1779), is supported by several morphological features distinguishing the two Pomphorhynchus species: 1. The basal parts of the proboscis hooks located on the posterior proboscis half possess proximal projections in P. tereticollis but not in P. laevis. This shape of the hook bases is clearly visible only in unfixed fresh worms; 2. The last hooks are situated at the anterior part of the bulbus or rarely at the posterior-most end of the proboscis in P. tereticollis, while they lie anterior to the end of the proboscis in P. laevis; 3. The proboscis hooks No. 5 or 6 are markedly stout (robust) and clearly distinct in comparison with the surrounding hooks in P. tereticollis, while less robust and more similar to the hooks in P. laevis. In addition, genetic divergence between P. tereticollis and P. laevis based on ITS1, ITS2 and COI sequencing supports the existence of two distinct species and reveals that some isolates previously identified as P. laevis were actually P. tereticollis. Previous and present morphological and genetic data show that both Pomphorhynchus species occur in freshwaters throughout Europe and may infect the same fish hosts, such as chub and barbel, and also several species of isopods (Gammaridae). This study also provides morphological evidence that Pomphorhynchus intermedius Engelbrecht, 1957 is a synonym of P. tereticollis, because the only discrimination character of the former species, the “existing but small proximal projections of basal parts of the proboscis hooks located on the posterior proboscis half” are present also in P. tereticollis.

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Genetic and morphological variability of whipworms Trichuris Roederer, 1761 (Nematoda: Trichuridae), parasites of small rodents in southwestern Europe, was studied. Isozyme patterns of natural populations of nematodes parasitizing rodent species of the Muridae (Apodemus sylvaticus, Apodemus flavicollis, Mus musculus) and Arvicolidae (Clethrionomys glareolus, Microtus agrestis, Microtus arvalis) were analyzed at 6 putative loci. Two diagnostic loci were found in T. muris from Muridae and from Arvicolidae. Thus, the existence of 2 species of Trichuris restricted to different host families was indicated. They included Trichuris muris Schrank, 1788, originally described as being from mice, and Trichuris arvicolae n. sp., parasitizing the above species of Arvicolidae. The morphological variability of both species was compared. Although ranges of all morphological characters of the new species overlapped with those of T. muris, stepwise discriminant analysis yielded a 100% accurate classification of females when using vagina length and egg size. Males of T. muris and T. arvicolae cannot be separated entirely. A set of 6 variables yielded 95.7% discrimination; the most discriminating variables were spicule size and body width.

76 SummaryThe species-specific ribosomal internal transcribed spacer 2 (ITS2) markers were designed for PCR-based molecular differentiation of Fasciola hepatica, Fascioloides magna, Dicrocoelium dendriticum and Paramphistomum cervi, liver and stomach flukes of domestic and free living ruminants. Complete ITS2 sequences were obtained for D. dendriticum and P. cervi, for the later species, ITS2 structure was determined for the first time. Intraspecific variation within geographically distant populations was found to be either very low (F. hepatica; D. dendriticum) or even absent (F. magna; P. cervi). ITS2 regions with the absence of intraspecific polymorphisms but with interspecific sequence heterogeneity were applied for design of speciesspecific primers. The specificity of developed primers was tested on genomic DNA isolated from adult individuals of studied fluke species. Application of the primers is of particular value for molecular differentiation of morphologically hardly distinguishable F. hepatica, F. magna and P. cervi eggs after coprological examinations.

Samples of males of Trichuris ovis (Abildgaard, 1795), T. skrjabini Baskakov, 1924, T. sylvilagi Tiner, 1950, T. suis (Schrank, 1788 and T. trichiura (L., 1771) were compared on the basis of 15 morphometric characters. An analysis of their variability, correlations and a discriminant analysis yielded information on the diagnostic value of these characters and on the best combination of characters necessary for the successful differentiation of the species studied. The morphological similarity of the species studied was also assessed. The length and width of the spicule and body length proved to be the best diagnostic characters for the trichurid males studied. They permitted fairly reliable differentiation of the species T. ovis, T. skrjabini and T. sylvilagi. The species which exhibited the greatest similarity, T. suis and T. trichiura, were frequently misidentified using these features only but could be readily differentiated using seven characters.