Fish-borne zoonoses are emerging worldwide, and although most human cases remain confined to tropical regions, particularly Southeast and East Asia, a few cases have been reported in Europe. This review summarizes published and new data on the life cycle of Metagonimus romanicus (misidentified as M. yokogawai, a human pathogen common in East Asia), a heterophyid trematode and one of the potentially fish-borne parasites in Europe. Metagonimus romanicus is distributed from the middle Danube in Central Europe (Slovakia) to eastern Ukraine (including the rivers of the Black Sea basin). Its distribution area coincides with that of its first intermediate hosts, the melanopsid snails Microcolpia daudebartii acicularis and Esperiana esperi. While M. romanicus most likely has a strict specificity for its first snail hosts, metacercariae are generalists and have been detected in over 50 freshwater fish species from 18 families, especially leuciscids. Despite its wide distribution and frequent occurrence in freshwater fish, the zoonotic potential of M. romanicus appears to be low. This is probably due to the exclusive localization of the metacercariae in the fish scales rather than musculature, as well as the rare consumption of raw or undercooked fish in Europe. However, some risk remains and a small number of undiagnosed human infections due to accidental ingestion of scales during the preparation and cleaning of fish cannot be ruled out.

• Keywords
• Cercariae, Europe, Fish, Freshwater, Metacercariae, Snails,
• Publication type
• Journal Article MeSH

The caryophyllidean tapeworms (Cestoda) of the genus Isoglaridacris Mackiewicz, 1965 are revised on the basis of the study of type specimens and newly collected material from suckers (Cypriniformes: Catostomidae) in North America. Molecular data reveal the presence of 14 lineages, each representing a separate species. An overview of all nominal species is provided, with updated information on their hosts, distribution and phylogenetic relationships. Isoglaridacris multivitellaria Amin, 1976 is excluded from Isoglaridacris, but its generic affiliation remains unclear, and it is considered incertae sedis. Homeomorpha mackiewiczi Dutton et Barger, 2014 from Minytrema melanops is transferred to Isoglaridacris as I. mackiewiczi (Dutton et Barger, 2014) new combination. Based on molecular and morphological data, four new species are described: Isoglaricris mattisi n. sp. from Moxostoma collapsum in South Carolina, USA, I. mcallisteri n. sp. from Erimyzon claviformis in Arkansas and Oklahoma, USA, I. mexicanus n. sp. from Moxostoma cf. austrinum in Chihuahua, Mexico, and I. floriani n. sp. from M. macrolepidotum in South Carolina. A key to the identification of all 16 valid species is provided. Isoglaridacris species exhibit strict host specificity, with most species parasitising only a single host species (strict specialists), while a few species occur in more than one species within the same host genus (congeneric specialists). The distribution range of Isoglaridacris species includes southern Canada, the United States and northwestern (nearctic) Mexico.

• Keywords
• Fish, Nearctic region, Phylogenetic relationships, Revision, Species diversity, Taxonomy,
• MeSH
• Cestoda * genetics   classification   anatomy & histology   MeSH
• Cestode Infections * parasitology   veterinary   MeSH
• Phylogeny * MeSH
• Cypriniformes * parasitology   MeSH
• Fish Diseases * parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• North America MeSH

Proteocephalids are a cosmopolitan and diverse group of tapeworms (Cestoda) that have colonized vertebrate hosts in freshwater and terrestrial environments. Despite the ubiquity of the group, key macroevolutionary processes that have driven the group's evolution have yet to be identified. Here, we review the phylogenetic relationships of proteocephalid tapeworms using publicly available (671) and newly generated (91) nucleotide sequences of the nuclear RNA28S and the mitochondrial MT-CO1 for 537 terminals. The main tree search was carried out under the parsimony optimality criterion, analysing different gene alignments simultaneously. Interestingly, we were not able to recover monophyly of the Proteocephalidae. Additionally, it was difficult to reconcile the tree with host and biogeographical data using traditional character optimization strategies in two dimensions. Therefore, we investigated if host and biogeographical data can be correlated with the parasite clades in a multidimensional space-thus considering multiple layers of information simultaneously. To that end, we used random forests (a class of machine learning models) to test the predictive potential of combined (not individual) host and biogeographical data in the context of the proteocephalid tree. Our resulting models can correctly place 88.85% (on average) of the terminals into eight representative clades. Moreover, we interactively increased the levels of clade perturbation probability and confirmed the expectation that model accuracy negatively correlates with the degree of clade perturbation. Our results show that host and biogeographical data can accurately predict proteocephalid clades in multidimensional space, even though they are difficult to optimize in the parasite tree. These results agree with the assumption that the evolution of proteocephalids is not independent of host and biogeography, and both may provide external support for our tree.

• MeSH
• Cestoda * genetics   classification   MeSH
• Phylogeny * MeSH
• Phylogeography MeSH
• Machine Learning * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

The caryophyllidean tapeworm Khawia armeniaca has long been regarded as an exceptionally widespread species within its genus, notable for its significant morphological variability. However, with the accumulation of molecular data from different fish hosts, K. armeniaca was suspected to represent a species complex. To clarify the true identity of these parasites, a comprehensive morphological and molecular study (using 18S, 28S and ITS2 ribosomal regions) of K. armeniaca tapeworms from barbels (Barbinae) across the Iberian Peninsula and the Middle East has been conducted. The results revealed two genetically distinct lineages within the K. armeniaca complex. The first lineage, found in Arabibarbus grypus, Barbus lacerta, Capoeta birunii, Carassobarbus luteus, Luciobarbus barbulus, L. esocinus and L. kersin in Iraq and Iran, is genetically congruent with K. armeniaca (Cholodkovsky, 1915), originally described from the Sevan khramulya (Capoeta sevangi) in Armenia. The second lineage, identified in Luciobarbus bocagei (type host), L. comizo and L. guiraonis from Portugal and Spain, is described as Khawia iberica n. sp. In addition to clear molecular divergence, K. iberica can be distinguished from K. armeniaca by notable morphological differences, including variations in the shape, structure and size of the ovary, the anterior extension of the vitelline follicles, the testes and several morphometric parameters.

• Keywords
• 18S rDNA, 28S rDNA, Cypriniformes, Europe, ITS2, Middle East, morphology, taxonomy, vicariance,
• MeSH
• Cestoda * classification   genetics   anatomy & histology   isolation & purification   MeSH
• Cestode Infections * veterinary   parasitology   epidemiology   MeSH
• Cyprinidae * parasitology   MeSH
• DNA, Helminth genetics   chemistry   MeSH
• Phylogeny MeSH
• Genetic Variation MeSH
• Fish Diseases * parasitology   epidemiology   MeSH
• RNA, Ribosomal, 18S genetics   MeSH
• RNA, Ribosomal, 28S genetics   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Portugal epidemiology   MeSH
• Spain epidemiology   MeSH
• Names of Substances
• DNA, Helminth MeSH
• RNA, Ribosomal, 18S MeSH
• RNA, Ribosomal, 28S MeSH

The parasite fauna of Neotropical reptiles is poorly known, and the number of parasites described in these hosts does not seem to correspond to the actual species diversity in this zoogeographical region. This also applies to tapeworms such as proteocephalids, which are rarely found in reptiles and are strictly specific to their reptilian hosts. In the present paper, three new species of Ophiotaenia La Rue, 1911 are described from three dipsadine snake species (Squamata: Colubridae) in Ecuador, namely O. jeanmarctouzeti sp. n. from the Neotropical blunt-headed treesnake Imantodes cenchoa (Linnaeus), O. barraganae sp. n. from the beautiful calico snake Oxyrhopus formosus (Wied-Neuwied) and O. velascoae sp. n. from the forest flame snake Oxyrhopus petolarius (Linnaeus). The new species are characterised by type 1 uterine development, the number and distribution of testes, the size of the scolex and other metric features. As no molecular data are available on the specimens collected more than 35 years ago, the phylogenetic relationships of the individual taxa are not known.

• Keywords
• Dipsadinae, Ophidia, South America, Tapeworms, morphology, species diversity, taxonomy,
• MeSH
• Cestoda * classification   isolation & purification   MeSH
• Cestode Infections veterinary   parasitology   epidemiology   MeSH
• Colubridae * parasitology   MeSH
• Species Specificity MeSH
• Phylogeny MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Ecuador MeSH

Tapeworms of the genus Spirometra Faust, Campbell et Kellogg, 1929 have long been known as intestinal parasites of carnivores and their larvae (spargana) have been found in various vertebrates. Nevertheless, their species diversity, host associations and geographical distribution remain poorly understood. Molecular data clearly confirm the validity of the genus, which has been synonymised by several authors with Diphyllobothrium Cobbold, 1858. Despite morphological similarities between the species of the two genera, they are not closely related and also differ in their life cycle. The present review provides a list of the species recognised as valid and additional genotypes that may represent other species, with a basic characterisation of each taxon and comments on their validity, the probable range of definitive and intermediate hosts, and their distribution. The existing taxonomic problems and the insufficient knowledge of the host specificity and distribution of Spirometra tapeworms can only be solved by combining molecular and morphological data, i.e. by comparing genetically characterised specimens with corresponding morphological vouchers (hologenophores). Further targeted sampling and surveys are required to clarify the distribution and host associations.

• Keywords
• Broad tapeworms, Diversity, Geographical distribution, Host range, Molecular phylogeny, Sparganosis, Zoonosis,
• Publication type
• Journal Article MeSH
• Review MeSH