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.

• 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

During an ichthyoparasitological survey in 2017-2019, six species of acanthocephalans were found among Taiwan's freshwater (Cypriniformes: Xenocyprididae, Cyprinidae) and marine fishes (Scombriformes: Scombridae, Trichiuridae; Anabantiformes: Channidae; Carangaria/misc: Latidae): Micracanthorhynchina dakusuiensis (Harada, 1938), Rhadinorhynchus laterospinosus Amin, Heckmann et Ha, 2011, Pallisentis rexus Wongkham et Whitfield, 1999, Longicollum sp., Bolbosoma vasculosum (Rudolphi, 1819), and one new species, Micracanthorynchina brevelemniscus sp. n. All species are morphologically characterised and illustrated using light and scanning electron microscopy. The finding of R. laterospinosus, P. rexus and B. vasculosum is the first record for these species in Taiwan. Micracanthorhynchina brevelemniscus is similar to Micracanthorhynchina motomurai (Harada, 1935) and M. dakusuiensis in proboscis armature but differs from M. motomurai by larger eggs (53-59 × 15-16 μm vs 40 × 16 μm) and by the number of cement glands (6 vs 4) and from M. dakusuiensis by shorter body length (2.2-2.9 mm vs 4.0 mm in males and 2.9-4.1 mm vs 7.6 mm in females), by the location of the organs of the male reproductive system (from level of the posterior third of the proboscis receptacle in M. brevelemniscus vs in the posterior half of the trunk in M. dakusuiensis), and by length of lemnisci (lemnisci shorter than the proboscis receptacle vs lemnisci longer than the proboscis receptacle). Phylogenetic analyses of almost complete 18S rRNA gene revealed paraphyly of the family Rhadinorhynchidae suggested in previous studies. Micracanthorhynchina dakusuiensis and M. brevelemniscus formed a strongly supported cluster, which formed the earliest diverging branch to the rest of the rhadinorhynchids and transvenids.

• MeSH
• Acanthocephala * anatomie a histologie   MeSH
• fylogeneze MeSH
• helmintózy zvířat * epidemiologie   MeSH
• máloostní * MeSH
• nemoci ryb * epidemiologie   MeSH
• Perciformes * MeSH
• ryby MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Taiwan MeSH

• MeSH
• Cestoda * MeSH
• cestodózy * veterinární   MeSH
• Cyprinidae * MeSH
• máloostní * MeSH
• nemoci ryb * MeSH
• sladká voda MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Monozoic tapeworms (Caryophyllidea) are dominant components of parasite communities of suckers (Catostomidae) in North America, with Biacetabulum Hunter, 1927 representing one of the more species-rich genera. Molecular (28S rDNA) and morphological (including scanning electron microscopy and histology) evaluation of newly collected tapeworms from different fish hosts revealed the existence of four similar (and three closely related) species of Biacetabulum. These four species differ from their congeners by having a long body (up to 48 mm long) with a very long, slender neck (its length represents ≥30% of total body length), a large, globular scolex with a prominent central acetabulum-like loculus on the dorsal and ventral sides, two pairs of shallow lateral loculi and a distinct, slightly convex apical disc, and a cirrus-sac that is situated between the anterior arms of the ovarian wings. Taken together, the morphological and molecular data and the host associations of these species provide evidence of their host specificity. Biacetabulum isaureae n. sp. occurs in notch clip redhorse, Moxostoma collapsum, in South Carolina (USA), B. longicollum n. sp. in silver redhorse, Moxostoma anisurum (type host), and golden redhorse, M. erythrurum, in Manitoba (Canada) and West Virginia (USA), B. overstreeti n. sp. in a spotted sucker, Minytrema melanops, in Mississippi, and B. hypentelii n. sp. in northern hogsucker, Hypentelium nigricans, in Tennessee (USA). The new species differ from each other in the number of postovarian vitelline follicles, the posterior extent of preovarian vitelline follicles and relative size of the cirrus sac.

• MeSH
• biologická evoluce * MeSH
• Cestoda genetika   MeSH
• cestodózy parazitologie   veterinární   MeSH
• interakce hostitele a parazita * MeSH
• máloostní parazitologie   MeSH
• nemoci ryb parazitologie   MeSH
• vznik druhů (genetika) * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Kanada MeSH
• Spojené státy americké MeSH

Seven new species of Dactylogyrus Diesing, 1850 (Dactylogyridae) are described from the gills of seven endemic species of cyprinoids (Cyprinidae, Leuciscidae) inhabiting the Balkan Peninsula: Dactylogyrus romuli n. sp. from Luciobarbus albanicus (Greece), Dactylogyrus remi n. sp. from Luciobarbus graecus (Greece), Dactylogyrus recisus n. sp. from Pachychilon macedonicum (Greece), Dactylogyrus octopus n. sp. from Tropidophoxinellus spartiaticus (Greece), Dactylogyrus vukicae n. sp. from Delminichthys adspersus (Bosnia and Herzegovina), Dactylogyrus leptus n. sp. from Chondrostoma knerii (Bosnia and Herzegovina), and Dactylogyrus sandai n. sp. from Telestes karsticus (Croatia). To delineate species boundaries, we used an integrative taxonomic approach combining morphological and genetic data. With these tools, we illustrate that some species of monogeneans considered as cryptic might be designated as pseudocryptic (morphologically similar, not easily differentiated) after a posteriori detailed morphological examination, as happened with D. romuli n. sp. and D. remi n. sp. Thus, for accurate species characterization, it is particularly important to acquire both morphological and molecular data from the same individual specimens, ideally along with illustrations of taxonomically important structures directly taken from hologenophores. Using phylogenetic reconstruction, we investigated the phylogenetic position of newly described Dactylogyrus species within Dactylogyrus species from Balkan cyprinoids with regard to morphological characteristics, host range, and geographical distribution.

• MeSH
• biodiverzita * MeSH
• druhová specificita MeSH
• fylogeneze * MeSH
• fylogeografie MeSH
• interakce hostitele a parazita * MeSH
• máloostní * parazitologie   MeSH
• paraziti * MeSH
• Trematoda * klasifikace   genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Balkánský poloostrov MeSH
• Chorvatsko MeSH

The sicklefin redhorse, Moxostoma sp. (Cypriniformes: Catostomidae), is an innominate imperiled catostomid endemic to the Hiwassee and Little Tennessee river basins, which has been restricted to a few tributaries of these systems by impoundments. During collections to propagate sicklefin redhorse for reintroduction, a myxozoan, described herein, was observed infecting sicklefin redhorse in the Little Tennessee River Basin, North Carolina. Myxobolus naylori Ksepka et Bullard sp. n. infects the stratum spongiosum covering the scales of sicklefin redhorse. Myxospores of the new species differ from all congeners by the combination of having a mucous envelope, intercapsular process, and sutural markings as well as lacking an iodinophilic vacuole in the sporoplasm. A phylogenetic analysis of the 18S rDNA gene recovered the new species in a polytomy with Myxobolus marumotoi Li et Sato, 2014 and a clade comprised of species of Myxobolus Bütschli, 1882; Thelohanellus Kudo, 1933, and Dicauda Hoffman et Walker, 1973. Histological sections of infected sicklefin redhorse skin revealed myxospores within a plasmodium in the stratum spongiosum dorsal to scales, encapsulated in collagen fibres, and associated with focal erosion of scales directly beneath the plasmodium; in some instances, the scale was perforated by the plasmodium. The specificity of the new species to sicklefin redhorse may make it a useful biological tag to differentiate sicklefin redhorse from morphologically similar species. The new species is the first parasite reported from sicklefin redhorse, a species of concern to the United States Fish and Wildlife Service. No species of Myxobolus has been reported from species of Moxostoma in the Southeast United States. As it was observed that Myxobolus minutus Rosser, Griffin, Quiniou, Alberson, Woodyard, Mischker, Greenway, Wise et Pote, 2016 is a primary junior homonym of Myxobolus minutus Nemeczek, 1911, we propose the replacement name Myxobolus diminutus (Rosser, Griffin, Quiniou, Alberson, Woodyard, Mischker, Greenway, Wise et Pote, 2016).

• MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• máloostní MeSH
• Myxobolus MeSH
• nemoci ryb epidemiologie   patologie   MeSH
• parazitární nemoci u zvířat epidemiologie   parazitologie   MeSH
• prevalence MeSH
• řeky MeSH
• ribozomální DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Severní Karolína MeSH

The Schistura robertsi species complex is a group of freshwater fish inhabiting streams in southeast Myanmar as well as in western and southern Thailand. In southern Thailand, the distribution exceeds the biogeographically important 'Surat Thani - Krabi line'. The complex is believed to include five described and one undescribed species, but monophyly and systematics of the group have never been studied explicitly. The present study aims to resolve the number of species within the Schistura robertsi group as well as their distribution areas and phylogenetic relations. We analysed mitochondrial and nuclear sequence data of 86 specimens from 47 localities and 18 morphological characters of 193 specimens. The phylogenetic analyses revealed the S. robertsi complex to be monophyletic and to be composed of ten major lineages. Six of them correspond to the known described or undescribed species, but another four newly identified clades reveal the existence of an overlooked diversity within the group. All genetic lineages are statistically highly supported and all are morphologically diagnosable, suggesting that they represent distinct species. The distribution areas of several clades overlap, the cases of direct co-occurrence show no sign of hybridisation.

• MeSH
• Bayesova věta MeSH
• biodiverzita * MeSH
• časové faktory MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• kalibrace MeSH
• máloostní anatomie a histologie   klasifikace   MeSH
• zeměpis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Myanmar MeSH
• Thajsko MeSH

Interspecific hybridization is a powerful evolutionary force. However, the investigation of hybrids requires the application of methodologies that provide efficient and indubitable identification of both parental subgenomes in hybrid individuals. Repetitive DNA, and especially the satellite DNA sequences (satDNA), can rapidly diverge even between closely related species, hence providing a useful tool for cytogenetic investigations of hybrids. Recent progress in whole-genome sequencing (WGS) offers unprecedented possibilities for the development of new tools for species determination, including identification of species-specific satDNA markers. In this study, we focused on spined loaches (Cobitis, Teleostei), a group of fishes with frequent interspecific hybridization. Using the WGS of one species, C. elongatoides, we identified seven satDNA markers, which were mapped by fluorescence in situ hybridization on mitotic and lampbrush chromosomes of C. elongatoides, C. taenia and their triploid hybrids (C. elongatoides × 2C. taenia). Two of these markers were chromosome-specific in both species, one had centromeric localization in multiple chromosomes and four had variable patterns between tested species. Our study provided a novel set of cytogenetic markers for Cobitis species and demonstrated that NGS-based development of satDNA cytogenetic markers may provide a very efficient and easy tool for the investigation of hybrid genomes, cell ploidy, and karyotype evolution.

• MeSH
• druhová specificita MeSH
• hybridizace genetická MeSH
• hybridizace in situ fluorescenční MeSH
• karyotyp MeSH
• karyotypizace MeSH
• klonální evoluce genetika   MeSH
• máloostní genetika   MeSH
• nepohlavní rozmnožování genetika   MeSH
• satelitní DNA genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Due to the extensive use of copper (Cu) in various commercial products, its existence in aquatic bodies (freshwater and marine) is not unusual. Cu is well known for its effect on the olfactory physiology of fish. However, there are limited studies on the effect of Cu on important ecological functions in fish (predator-prey dynamics) that are primarily influenced by olfaction. In a series of experiments, we studied the effect of Cu exposure on the chemoreceptive behavior of the prey fish, Lepidocephalichthys thermalis. Prey fishes were exposed to an environmentally relevant concentration (5 μg/L) of Cu for 3 h and the anti-predator responses against native (Channa gachua) and alien predatory fish (tilapia) were quantified using an ethological assay. Cu exposed prey fishes did not recognize the native predator and had a lower survival rate than control (unexposed) fishes in predation trials. Cu exposed prey fishes have failed to learn associatively to detect a non-native predator resulting in higher mortality in prey population in direct encounters with tilapia. However, such a lack of predator recognition was found to be short-term and the treated prey fishes recovered anti-predator responses within 72 h. In addition, Cu inactivated the alarm cue which acts as a signal for the presence of predators and ensures associative learning and therefore it was considered to be an 'info-disruptor' in the present study. These outcomes together demonstrate that even at low concentration, Cu influences ecological decisions and survival against predators. Owing to the ubiquitous occurrence of Cu in water bodies, the present investigation will contribute to the knowledge of how environmental stressors alter the crucial ecological decisions of prey individuals in aquatic ecosystems. In addition, we suggest that freshwater reservoirs containing high levels of Cu could be unsuitable for the long-term survival of prey fishes and freshwater biodiversity.

• MeSH
• ekosystém MeSH
• lidé MeSH
• máloostní * MeSH
• měď * toxicita   MeSH
• predátorské chování MeSH
• ryby MeSH
• sladká voda MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Western Southeast Asia is hosting one of the world's most diverse faunas, and one of the reasons for this huge diversity is the complex geologic past of the area, increasing the frequency of isolation and expansion events over evolutionary time scale. As an example case, the present study reveals the phylogeny and biogeographic history of the Paracanthocobitis zonalternans species complex, small benthic freshwater fish (Teleostei: Nemacheilidae) that are commonly occurring across western Southeast Asia (from central Myanmar through western and southern Thailand to northern Malaysia). The group is particularly interesting since it occurs in three biogeographic subdivisions (Indian, Indochinese, Malay/Sundaic) and across all of the major biogeographic barriers in the region. Basing on mitochondrial and nuclear sequence data of 93 samples from about 50 localities we found six major clades, most with exclusive geographic distribution. Divergence time dated the origin of the P. zonalternans species complex to early Miocene (17.8 MYA) and a biogeographic analysis identified the Tenasserim region as the ancestral region. From this region the fish spread during periods of lowered global sea level, particularly during late Miocene (11-8 MYA) northwards into all Burmese river basins and southwards into south Thailand and northern Malaysia. Besides lowered global sea level periods, local stream capture events allowed the complex to expand, e.g. into the Mae Klong basin. Strong fragmentations during periods with elevated sea level during the Pliocene and Pleistocene repeatedly restricted populations to refuges and shaped the observed major lineages. Our results document a higher diversity within the P. zonalternans species complex than formerly believed and a strong impact of global sea level on its evolutionary history. Low sea levels promoted dispersal and elevated sea levels fragmentation events. A very similar impact of sea level changes can be expected in all stationary fauna (freshwater and terrestrial) in all non-mountainous coastal regions worldwide.

• MeSH
• Bayesova věta MeSH
• biodiverzita * MeSH
• časové faktory MeSH
• fylogeneze MeSH
• fylogeografie * MeSH
• máloostní fyziologie   MeSH
• mitochondriální DNA genetika   MeSH
• mořská voda * MeSH
• sladká voda * MeSH
• společenstvo * MeSH
• zeměpis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• jihovýchodní Asie MeSH