Scanning electron microscopy was used to study the scolex morphology of 3 morphotypes of metacestodes of the order Phyllobothriidea (Cestoda) from the spiral intestine of the North Sea rabbitfish Chimaera monstrosa and the intestine and gall bladder of the pink salmon Oncorhynchus gorbuscha. Transmission electron microscopy allowed a detailed examination of the ultrastructure of the tegument, unicellular gland cells, muscle cells, and calcareous corpuscles of metacestodes of different sizes from chimaeras. Based on our morphological data, we propose that the studied intestinal metacestodes from chimaeras and pink salmon belong to the type XV metacestodes of Jensen and Bullard, possibly related to members of the genus Clistobothrium Dailey and Vogelbein, 1990.
- Klíčová slova
- Alaska, Cestoda, Larvae, Morphology, Norway, Phyllobothriidea, Pink salmon, Rabbitfish, SEM, TEM, Ultrastructure,
- MeSH
- Cestoda * ultrastruktura klasifikace anatomie a histologie MeSH
- cestodózy * veterinární parazitologie MeSH
- larva ultrastruktura anatomie a histologie MeSH
- mikroskopie elektronová rastrovací veterinární MeSH
- nemoci ryb * parazitologie MeSH
- Salmonidae * parazitologie MeSH
- střeva parazitologie MeSH
- transmisní elektronová mikroskopie veterinární MeSH
- žlučník parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články 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.
- Klíčová slova
- Fish, Nearctic region, Phylogenetic relationships, Revision, Species diversity, Taxonomy,
- MeSH
- Cestoda * genetika klasifikace anatomie a histologie MeSH
- cestodózy * parazitologie veterinární MeSH
- fylogeneze * MeSH
- máloostní * parazitologie MeSH
- nemoci ryb * parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Severní Amerika MeSH
Diphyllobothriosis is a parasitic infection of humans caused by the broad fish tapeworm (Dibothriocephalus latus; synonym Diphyllobothrium latum). This disease is widespread in the Northern Hemisphere including Europe. Popular sport fish such as perch (Perca fluviatilis) and pike (Esox lucius) are the source of human infection. Here we document the first autochthonous case of diphyllobothriosis linked to the consumption of raw pike roe (caviar) originating from a popular tourist destination in South Bohemia. This is probably a recent introduction of the parasite into the Lipno Reservoir, which may represent a new focus of diphyllobothriosis, a zoonotic, fish-borne disease.
- Klíčová slova
- Central Europe, Freshwater fish, Lipno Reservoir, broad fish tapeworm, pike, roe, zoonosis,
- MeSH
- difylobotriáza * diagnóza parazitologie MeSH
- Diphyllobothrium * izolace a purifikace MeSH
- lidé MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- Geografické názvy
- Česká republika 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 * genetika klasifikace MeSH
- fylogeneze * MeSH
- fylogeografie MeSH
- strojové učení * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články 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.
- Klíčová slova
- 18S rDNA, 28S rDNA, Cypriniformes, Europe, ITS2, Middle East, morphology, taxonomy, vicariance,
- MeSH
- Cestoda * klasifikace genetika anatomie a histologie izolace a purifikace MeSH
- cestodózy * veterinární parazitologie epidemiologie MeSH
- Cyprinidae * parazitologie MeSH
- DNA helmintů genetika chemie MeSH
- fylogeneze MeSH
- genetická variace MeSH
- nemoci ryb * parazitologie epidemiologie MeSH
- RNA ribozomální 18S genetika MeSH
- RNA ribozomální 28S genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Portugalsko epidemiologie MeSH
- Španělsko epidemiologie MeSH
- Názvy látek
- DNA helmintů MeSH
- RNA ribozomální 18S MeSH
- RNA ribozomální 28S MeSH
The diphyllobothriid tapeworm Dibothriocephalus dendriticus, one of the causative agents of the fish-borne zoonosis dibothriocephalosis, is mainly distributed in the Arctic/subarctic and temperate zones of the Northern Hemisphere (Europe, North America, and Asia), but also in the southern cone region of South America (Patagonia). The genetic structure and gene flow among 589 individuals of D. dendriticus, representing 20 populations, were studied using the mitochondrial cox1 gene as the first choice marker and 10 polymorphic nuclear microsatellite loci as a dominant molecular tool. The haplotype network of 30 cox1 haplotypes and Principal Coordinate Analysis/Structure analysis based on microsatellite data revealed close genetic relationships among populations within continents, namely northern and northwestern Europe (Norway, Finland, and UK/Scotland), North America (USA/Alaska, USA/Oregon, and Greenland), and South America (Argentina and Chile). The population from Iceland, located on the Mid-Atlantic Ridge between North America and Europe, was related to both Europe and North America. The mixed Nearctic and Palaearctic origin of D. dendriticus in Iceland was confirmed by a coalescent-based analysis of the microsatellite loci (in Migrate software). The most likely scenarios suggested that the Icelandic population is a genetic admixture of tapeworms from northwestern Europe and USA/Alaska. These findings corresponded with the distribution and migratory routes of piscivorous birds of the family Laridae, the main definitive hosts of D. dendriticus. The origin of an apparently non-native population of D. dendriticus in Patagonia was investigated in detail. The two most plausible hypotheses based on Migrate analysis represented different scenarios. One of them points to a European origin of the Patagonian population, the other to a North American origin. Future research with more extensive and a geographically broader sampling set is recommended to trace dispersal routes of D. dendriticus in Patagonia.
- Klíčová slova
- Broad tapeworm, Cox1, Diphyllobothriosis, Diphyllobothrium dendriticum, Fish-borne zoonosis, Microsatellite loci, Migratory routes, Mitochondrial DNA,
- MeSH
- Cestoda * genetika klasifikace MeSH
- cestodózy * veterinární parazitologie epidemiologie MeSH
- fylogeografie MeSH
- genetická variace * MeSH
- haplotypy MeSH
- mikrosatelitní repetice MeSH
- nemoci ryb parazitologie MeSH
- tok genů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- Jižní Amerika MeSH
- Severní Amerika MeSH
Extracellular vesicles (EVs) from parasites have been identified as potent modulators of host-parasite interactions. However, their biogenesis and secretory activity are still poorly understood. Here we present a comprehensive examination of the secretory dynamics of two distinct EV fractions isolated from the adult tapeworm Hymenolepis diminuta. Additionally, we perform a detailed analysis of changes in proteomic content and morphology during EV secretion, utilising electron tomography to shed light on a previously described novel mechanism of EV biogenesis via bead-like protrusion. Our findings reveal a significant decrease in EV secretion between 24 and 48 h of in vitro cultivation when external host stimuli are no longer present. Finally, this study addresses, for the first known time, the potential bias in EV analysis resulting from extended in vitro cultivation of model parasites.
- Klíčová slova
- ESP, Electron microscopy, Exosomes, LC–MS/MS, Proteins, Secretion, Size exclusion chromatography,
- MeSH
- extracelulární vezikuly * metabolismus ultrastruktura MeSH
- Hymenolepis diminuta * fyziologie růst a vývoj metabolismus ultrastruktura MeSH
- interakce hostitele a parazita * MeSH
- proteomika MeSH
- tomografie elektronová MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The present study describes the morphology and phylogenetic position of two specimens of Bertiella Stiles et Hassall, 1902 (Cestoda, Anoplocephalidae) from Rattus tanezumi (Temminck) (Muridae) from Đồng Tháp Province in southern Vietnam. The phylogenetic analysis was based on sequences of the large subunit ribosomal RNA gene (28S). The specimens were described and shown to be morphologically similar to Bertiella anapolytica Baylis, 1934 from Rattus spp. from Indonesia (Sumatra, type locality) and Australia, except for a few quantitative differences. The identification was confirmed by the phylogenetic analysis, which showed a strong affinity and fairly limited genetic divergence between the specimens from Vietnam and Australia. This is the first verified case of Bertiella in murid rodents from continental Eurasia. The uterine pore and associated canal present in the posterolateral corners of gravid proglottids of B. anapolytica are considered to form a true, functional structure used for egg release prior to apolysis. The phylogenetic analysis suggested that B. anapolytica has diverged as a consequence of a shift from marsupials, which probably took place east of the Wallace's line, either in Wallacea or Australasia. The presence of B. anapolytica west of the Wallace's line (Vietnam, Sumatra), where marsupials are absent, may be explained by a westward dispersal in commensal rats, possibly Rattus exulans (Peale), a species transported throughout the Pacific and South-East Asia by prehistoric people.
- Klíčová slova
- 28S, Cyclophyllidea, Muridae, Vietnam, phylogeny, rodents,
- MeSH
- biologická evoluce MeSH
- Cestoda * genetika klasifikace anatomie a histologie izolace a purifikace MeSH
- cestodózy * parazitologie veterinární epidemiologie MeSH
- fylogeneze MeSH
- krysa rodu Rattus parazitologie MeSH
- nemoci hlodavců * parazitologie epidemiologie MeSH
- RNA ribozomální 28S genetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus parazitologie MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Austrálie MeSH
- Vietnam epidemiologie MeSH
- Názvy látek
- RNA ribozomální 28S MeSH
In this study, we use an integrative taxonomic approach to redescribe Schyzocotyle nayarensis (Malhotra, 1983) (Cestoda: Bothriocephalidae), based on newly collected specimens from the type-host Raiamas bola (Hamilton, 1822) (Cypriniformes: Danionidae) in Fulbari, Siliguri, West Bengal, India. The detailed morphological assessment, from whole mounts, histology and scanning electron microscopy, offers additional insights into the scolex structure, vitelline follicles, and egg morphology. Molecular data from this and previous studies corroborate the identity and systematics of S. nayarensis as a bothriocephalid closely related to the Asian Fish Tapeworm, Schyzocotyle acheilognathi (Yamaguti, 1934). This study elucidates the historical context and taxonomic ambiguities surrounding S. nayarensis, emphasizing the key role of the scolex in both generic and species identification. Amendments to the diagnosis of Schyzocotyle Akhmerov, 1960 are proposed. A differential diagnosis of the two valid species within the genus, namely S. acheilognathi and S. nayarensis, is also provided. An evaluation of the taxonomic status of Bothriocephalus teleostei Malhotra, 1984, and Capooria barilii Malhotra, 1985 suggests that they may be S. nayarensis. Finally, we posit that none of the ten species of Ptychobothrium Lönnberg, 1889 described from Indian freshwater teleosts belong to this genus but instead appear to be a mix of species belonging to Schyzocotyle, Senga Dollfus, 1934, and possibly even Proteocephalidae La Rue, 1911; all require further study based on newly collected, properly fixed specimens and an integrated taxonomic approach. Finally, future survey studies may reveal hidden diversity of Schyzocotyle species in Indian cyprinoids.
- Klíčová slova
- Cestoda, integrative taxonomy, molecular data, scanning electron microscopy,
- MeSH
- Cestoda * klasifikace anatomie a histologie ultrastruktura izolace a purifikace genetika MeSH
- cestodózy * veterinární parazitologie MeSH
- fylogeneze * MeSH
- máloostní parazitologie MeSH
- mikroskopie elektronová rastrovací * veterinární MeSH
- nemoci ryb * parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Indie 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.
- Klíčová slova
- Dipsadinae, Ophidia, South America, Tapeworms, morphology, species diversity, taxonomy,
- MeSH
- Cestoda * klasifikace izolace a purifikace MeSH
- cestodózy veterinární parazitologie epidemiologie MeSH
- Colubridae * parazitologie MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Ekvádor MeSH