After the break-up of Gondwana dispersal of organisms between America, Australia and Africa became more complicated. One of the possible remaining paths led through Antarctica, that was not yet glaciated and it remained habitable for many organisms. This favourable climate made Antarctica an important migration corridor for organisms with good dispersal ability, such as Aculeata (Hymenoptera), till the Oligocene cooling. Here we tested how cooling of Antarctica impacted global dispersal of Aculeata parasites (Strepsiptera: Xenidae). Our data set comprising six nuclear genes from a broad sample of Xenidae. Bayesian dating was used to estimate divergence times in phylogenetic reconstruction. Biogeography was investigated using event-based analytical methods: likelihood-based dispersal-extinction-cladogenesis and Bayesian models. The Bayesian model was used for reconstruction of ancestral host groups. Biogeographical methods indicate that multiple lineages were exchanged between the New World and the Old World + Australia until the Antarctica became completely frozen over. During the late Paleogene and Neogene periods, several lineages spread from the Afrotropics to other Old World regions and Australia. The original hosts of Xenidae were most likely social wasps. Within one lineage of solitary wasp parasites, parallel switch to digger wasps (Sphecidae) occurred independently in the New World and Old World regions. The biogeography and macroevolutionary history of Xenidae can be explained by the combination of dispersal, lineage extinction and climatic changes during the Cenozoic era. A habitable Antarctica and the presence of now-submerged islands and plateaus that acted as a connection between the New World and Old World + Australia provided the possibility for biotic exchanges of parasites along with their hymenopteran hosts. Although Xenidae are generally host specialists, there were significant host switches to unrelated but ecologically similar hosts during their evolution. There is little or no evidence for cophylogeny between strepsipteran parasites and hymenopteran lineages.

• MeSH
• Bayes Theorem MeSH
• Biological Evolution * MeSH
• Phylogeny MeSH
• Phylogeography MeSH
• Host-Parasite Interactions * MeSH
• Parasites physiology   MeSH
• Likelihood Functions MeSH
• Genetic Speciation MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Antarctic Regions MeSH

Geographical isolation, habitat variation and trophic specialization have contributed to a large extent to the astonishing diversity of cichlid fishes in the Great East African lakes. Because parasite communities often vary across space and environments, parasites can accompany and potentially enhance cichlid species diversification. However, host dispersal may reduce opportunities for parasite-driven evolution by homogenizing parasite communities and allele frequencies of immunity genes. To test for the relationships between parasite community variation, host dispersal and parasite-induced host evolution, we studied two sympatric cichlid species with contrasting dispersal capacities along the shores of southern Lake Tanganyika. Whereas the philopatric Tropheus moorii evolved into several genetically differentiated colour morphs, Simochromis diagramma is phenotypically rather uniform across its distribution range and shows only weak population structure. Populations of both species were infected with divergent parasite communities and harbour differentiated variant pools of an important set of immune genes, the major histocompatibility complex (MHC). The overall extent of geographical variation of parasites and MHC genes was similar between host species. This indicates that immunogenetic divergence among populations of Lake Tanganyika cichlids can occur even in species that are strongly dispersing. However, because this also includes species that are phenotypically uniform, parasite-induced evolution may not represent a key factor underlying species diversification in this system.

• MeSH
• Cichlids genetics   immunology   parasitology   MeSH
• Phenotype MeSH
• Major Histocompatibility Complex genetics   MeSH
• Immunogenetics * MeSH
• Parasites MeSH
• Genetics, Population MeSH
• Animal Distribution * MeSH
• Sympatry * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Tanzania MeSH

BACKGROUND: Fascioloides magna (Trematoda: Fasciolidae) is an important liver parasite of a wide range of free-living and domestic ruminants; it represents a remarkable species due to its large spatial distribution, invasive character, and potential to colonize new territories. The present study provides patterns of population genetic structure and admixture in F. magna across all enzootic regions in North America and natural foci in Europe, and infers migratory routes of the parasite on both continents. METHODS: In total, 432 individuals from five North American enzootic regions and three European foci were analysed by 11 microsatellite loci. Genetic data were evaluated by several statistical approaches: (i) the population genetic structure of F. magna was inferred using program STRUCTURE; (ii) the genetic interrelationships between populations were analysed by PRINCIPAL COORDINATES ANALYSIS; and (iii) historical dispersal routes in North America and recent invasion routes in Europe were explored using MIGRATE. RESULTS: The analysis of dispersal routes of the parasite in North America revealed west-east and south-north lineages that partially overlapped in the central part of the continent, where different host populations historically met. The exact origin of European populations of F. magna and their potential translocation routes were determined. Flukes from the first European focus, Italy, were related to F. magna from northern Pacific coast, while parasites from the Czech focus originated from south-eastern USA, particularly South Carolina. The Danube floodplain forests (third and still expanding focus) did not display relationship with any North American population; instead the Czech origin of the Danube population was indicated. A serial dilution of genetic diversity along the dispersion route across central and eastern Europe was observed. The results of microsatellite analyses were compared to previously acquired outputs from mitochondrial haplotype data and correlated with past human-directed translocations and natural migration of the final cervid hosts of F. magna. CONCLUSIONS: The present study revealed a complex picture of the population genetic structure and interrelationships of North American and European populations, global distribution and migratory routes of F. magna and an origin of European foci.

• MeSH
• Global Health MeSH
• Fasciolidae classification   genetics   isolation & purification   MeSH
• Genotyping Techniques MeSH
• Trematode Infections epidemiology   transmission   MeSH
• Microsatellite Repeats MeSH
• Deer * MeSH
• Zoonoses epidemiology   parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Europe epidemiology   MeSH
• North America epidemiology   MeSH

Susceptibility to parasite infection was examined in a field experiment for four populations of 0+ juvenile European bitterling (Rhodeus amarus): one sympatric to local parasite fauna, one allopatric, and two hybrid populations. Significantly higher parasite abundance was recorded in the allopatric bitterling population, suggesting a maladaptation of parasites to their sympatric host. Type of parasite life cycle played an important role in host-parasite interactions. While the abundance of allogenic species between populations was comparable, a significant difference was found in abundance of autogenic parasite species between fish populations, with the allopatric population more infected. These results correspond with a prediction of higher dispersion probability and higher gene flow among geographically distant populations of allogenic species as compared to autogenic species. Increased susceptibility to parasites that do not occur within the natural host's geographical distribution was found in the allopatric host, but only for autogenic species. A difference in infection susceptibility was detected among populations of early-hatched bitterling exposed to infection during a period of high parasite abundance and richness in the environment. Differences in parasite abundance and species diversity among populations diminished, however, with increasing time of exposure. No difference was found within late-hatched populations, probably due to a lower probability of infection in late-hatched cohorts.

• MeSH
• Biodiversity MeSH
• Chimera parasitology   MeSH
• Cyprinidae parasitology   MeSH
• Host-Parasite Interactions MeSH
• Disease Susceptibility MeSH
• Fish Diseases parasitology   MeSH
• Parasitic Diseases, Animal parasitology   MeSH
• Parasites classification   isolation & purification   pathogenicity   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Studies of food webs suggest that limited nonrandom dispersal can play an important role in structuring food webs. It is not clear, however, whether density-dependent dispersal fits empirical patterns of food webs better than density-independent dispersal. Here, we study a spatially distributed food web, using a series of population-dispersal models that contrast density-independent and density-dependent dispersal in landscapes where sampled sites are either homogeneously or heterogeneously distributed. These models are fitted to empirical data, allowing us to infer mechanisms that are consistent with the data. Our results show that models with density-dependent dispersal fit the α, β, and γ tritrophic richness observed in empirical data best. Our results also show that density-dependent dispersal leads to a critical distance threshold beyond which site similarity (i.e., β tritrophic richness) starts to decrease much faster. Such a threshold can also be detected in the empirical data. In contrast, models with density-independent dispersal do not predict such a threshold. Moreover, preferential dispersal from more centrally located sites to peripheral sites does not provide a better fit to empirical data when compared with symmetric dispersal between sites. Our results suggest that nonrandom dispersal in heterogeneous landscapes is an important driver that shapes local and regional richness (i.e., α and γ tritrophic richness, respectively) as well as the distance-decay relationship (i.e., β tritrophic richness) in food webs.

• MeSH
• Models, Biological * MeSH
• Herbivory * MeSH
• Host-Parasite Interactions MeSH
• Aphids physiology   MeSH
• Food Chain * MeSH
• Wasps physiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geographicals
• Czech Republic MeSH

Overlapping distributions of hosts and parasites are critical for successful completion of multi-host parasite life cycles and even small environmental changes can impact on the parasite's presence in a host or habitat. The generalist Cardiocephaloides longicollis was used as a model for multi-host trematode life cycles in marine habitats. This parasite was studied to quantify parasite dispersion and transmission dynamics, effects of biological changes and anthropogenic impacts on life cycle completion. We compiled the largest host dataset to date, by analysing 3351 molluscs (24 species), 2108 fish (25 species) and 154 birds (17 species) and analysed the resultant data based on a number of statistical models. We uncovered extremely low host specificity at the second intermediate host level and a preference of the free-swimming larvae for predominantly demersal but also benthic fish. The accumulation of encysted larvae in the brain with increasing fish size demonstrates that parasite numbers level off in fish larger than 140mm, consistent with parasite-induced mortality at these levels. The highest infection rates were detected in host species and sizes representing the largest fraction of Mediterranean fishery discards (up to 67% of the total catch), which are frequently consumed by seabirds. Significantly higher parasite densities were found in areas with extensive fishing activity than in those with medium and low activity, and in fish from shallow lagoons than in fish from other coastal areas. For the first time, C. longicollis was also detected in farmed fish in netpens. Fishing generally drives declines in parasite abundance, however, our study suggests an enhanced transmission of generalist parasites such as C. longicollis, an effect that is further amplified by the parasite's efficient host-finding mechanisms and its alteration of fish host behaviour by larvae encysted in the brain. The anthropogenic impact on the distribution of trophically-transmitted, highly prevalent parasites likely results in a strong effect on food web structure, thus making C. longicollis an ideal bioindicator to compare food webs in natural communities versus those impacted by fisheries and aquaculture.

• MeSH
• Ecosystem MeSH
• Snails parasitology   MeSH
• Host Specificity MeSH
• Trematode Infections parasitology   transmission   veterinary   MeSH
• Human Activities MeSH
• Mollusca classification   parasitology   MeSH
• Bird Diseases parasitology   transmission   MeSH
• Fish Diseases parasitology   transmission   MeSH
• Food Chain MeSH
• Birds MeSH
• DNA, Ribosomal chemistry   MeSH
• RNA, Ribosomal, 28S genetics   MeSH
• Fisheries MeSH
• Fishes anatomy & histology   classification   MeSH
• Sequence Analysis, DNA veterinary   MeSH
• Life Cycle Stages * MeSH
• Trematoda classification   genetics   growth & development   MeSH
• Body Size MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Black Sea MeSH
• Mediterranean Sea MeSH

The poorly known proteocephalidean cestode Macrobothriotaenia ficta (Meggitt, 1931) from the sunbeam snake Xenopeltis unicolor (Ophidia: Xenopeltidae) is redescribed on the basis of re-examination of its type specimens from Burma (Myanmar), and vouchers from Thailand and Vietnam. The peculiar morphology of the scolex, which is formed by four pedunculate lobe-bearing pincer-shaped suckers, is described for the first time using scanning electron microscopy. In scolex morphology, M. ficta closely resembles phyllobothriidean cestodes, parasites of elasmobranchs. However, this similarity does not reflect phylogenetic relatedness of these cestodes but instead presents an example of convergent morphological evolution of attachment organs of unrelated groups of cestodes that parasitize different groups of vertebrates. Besides scolex morphology, the genus is characterised by the possession of a very large cirrus-sac, which may reach up to the midline of proglottides, few testes (less than 60), vitelline follicles limited to the dorsal side of proglottides, a large vaginal sphincter, and eggs with a three-layered embryophore covered with rounded projections. Numerous errors in the diagnosis of M. ficta, which appeared in the literature as a result of uncritical compilation of data without examination of original material, are corrected. Multilocus phylogenetic analysis of nuclear ribosomal RNA genes ssr- and lsr-DNA and mitochondrial genes rrnL and cox1 place this species among other snake-parasitizing proteocephalideans of the genus Ophiotaenia. The convergent evolution of scolex morphology across distantly related taxa is discussed.

• MeSH
• Animal Structures anatomy & histology   MeSH
• Biological Evolution MeSH
• Cestoda anatomy & histology   classification   genetics   isolation & purification   MeSH
• Cestode Infections parasitology   veterinary   MeSH
• Phylogeny MeSH
• Snakes classification   parasitology   MeSH
• Animal Distribution MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Myanmar MeSH
• Vietnam MeSH

Trait-based research holds high potential to unveil ecological and evolutionary processes. Functional traits are fitness-related characteristics of individuals, which are measured at individual level and defined without using information external to the individual. Despite the usefulness of the functional approach to understand the performance of individuals in ecosystems, and parasitism being the most common life-history strategy on Earth, studies based on functional traits of parasites are still scarce. Since the choice of functional traits is a critical step for any study, we propose a core list of seven functional traits of metazoan parasites, related to three universal challenges faced by organisms (dispersal, establishment, and persistence), and give guidelines to define appropriate functional traits in future parasite community studies.

• MeSH
• Models, Biological MeSH
• Ecosystem MeSH
• Host-Parasite Interactions physiology   MeSH
• Parasites physiology   MeSH
• Parasitology MeSH
• Life Cycle Stages MeSH
• Animals MeSH
• Life History Traits * MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

Monogenean parasites with a broad host range and direct life cycle provide insight into population genetic structure and dispersal processes. Dactylogyrus vistulae infects over 50 cyprinoid fish species across the western Palearctic, making it an ideal model for assessing host and geographic influences on parasite population structure. Herein, we utilized 20 microsatellite loci and mitochondrial COI sequences to analyze the genetic variability and structure of D. vistulae populations, with a deeper focus on Czech river systems. Low allelic variance was observed across most populations, except in the Aoos River, Greece, where high genetic diversity suggests either a large population size or an ancestral refugium. Moderate variance was detected in the Middle East, though some Anatolian populations exhibited reduced diversity, likely due to recent colonization. Czech populations showed weak genetic structuring despite occupying distinct river basins, likely due to fish translocations. Mitochondrial COI analysis revealed up to 18.5% haplotype divergence, with the highest diversity in the Padano-Venetian, Caspian Sea, and Dalmatian districts. Dalmatian haplotypes formed a distinct haplogroup, though genetic similarities between Padano-Venetian and Dalmatian populations suggest historical connections or fish host introductions. These results support a south-to-north D. vistulae dispersal through the Balkans, associated with cyprinoid fish migration. This study highlights the roles of host dispersal, environmental factors, and human influence in shaping fish parasite population structure, emphasizing the need for further genomic and ecological research.

• MeSH
• Cyprinidae * parasitology   MeSH
• Phylogeny MeSH
• Genetic Variation * MeSH
• Haplotypes MeSH
• Trematode Infections * veterinary   parasitology   epidemiology   MeSH
• Microsatellite Repeats MeSH
• Fish Diseases * parasitology   epidemiology   MeSH
• Platyhelminths * genetics   classification   isolation & purification   MeSH
• Genetics, Population MeSH
• Electron Transport Complex IV genetics   MeSH
• Gills * parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH

INTRODUCTION: Intertidal rock pools where fish and invertebrates are in constant close contact due to limited space and water level fluctuations represent ideal conditions to promote life cycles in parasites using these two alternate hosts and to study speciation processes that could contribute to understanding the roles of parasitic species in such ecosystems. MATERIAL AND METHODS: Gall bladder and liver samples from five clinid fish species (Blenniiformes: Clinidae) were morphologically and molecularly examined to determine the diversity, prevalence, distribution and host specificity of Ceratomyxa parasites (Cnidaria: Myxozoa) in intertidal habitats along the coast of South Africa. Phylogenetic relationships of clinid ceratomyxids based on the SSU rDNA, LSU rDNA and ITS regions were assessed additionally to the investigation of population genetic structure of Ceratomyxa cottoidii and subsequent comparison with the data known from type fish host Clinus cottoides. RESULTS AND DISCUSSION: Seven Ceratomyxa species including previously described Ceratomyxa dehoopi and C. cottoidii were recognized in clinids. They represent a diverse group of rapidly evolving, closely related species with a remarkably high prevalence in their hosts, little host specificity and frequent concurrent infections, most probably as a result of parasite radiation after multiple speciation events triggered by limited host dispersal within restricted spaces. C. cottoidii represents the most common clinid parasite with a population structure characterized by young expanding populations in the south west and south east coast and by older populations in equilibrium on the west coast of its distribution. Parasite and fish host population structures show overlapping patterns and are very likely affected by similar oceanographic barriers possibly due to reduced host dispersal enhancing parasite community differentiation. While fish host specificity had little impact on parasite population structure, the habitat preference of the alternate invertebrate host as well as tidal water exchange may be additional crucial variables affecting the dispersal and associated population structure of C. cottoidii.

• MeSH
• Phylogeny MeSH
• Host-Parasite Interactions genetics   physiology   MeSH
• Myxozoa classification   genetics   MeSH
• Fish Diseases parasitology   MeSH
• Parasitic Diseases, Animal parasitology   MeSH
• Parasites classification   genetics   MeSH
• Genetics, Population methods   MeSH
• DNA, Ribosomal genetics   MeSH
• Fishes parasitology   MeSH
• Life Cycle Stages genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• South Africa MeSH