Dasyrhynchus giganteus plerocercoids encysting in the musculature of Indian halibut (Psettodes erumei): seasonal prevalence, morpho-molecular characterization, and histopathological alterations.

This study investigated the prevalence, morphology, molecular identification, and histopathological effects of larval tapeworms (plerocercoids) infecting the skeletal muscles of the Indian halibut (Psettodes erumei) collected from the coastal waters of the Arabian Gulf. Numerous oval or round blastocysts, measuring 13-26 mm, were found embedded within the muscular tissues of the Indian halibut, rendering the fish unsuitable for human consumption. Morphological and molecular analyses identified the plerocercoids as Dasyrhynchus giganteus (family Dasyrhynchidae), with an overall prevalence of 15.4%. The seasonal prevalence was the highest in summer (14.6%), followed by spring (10.6%), winter (4.4%), and autumn (3.5%). Infection rates increased with fish size. Histopathological examination revealed fibrous connective tissue capsules surrounding the larvae, causing muscular atrophy and degenerative changes, with few inflammatory eosinophilic cells. Molecular and phylogenetic analysis of the 28S rDNA gene sequences confirmed the specimens as D. giganteus, clustered closely with other sequences of D. giganteus with 100% bootstrap values. This study provided valuable insights into the parasitic infection dynamics, seasonal variation, molecular identification, and histopathological effects, highlighting the importance of monitoring fish for food safety and public health implications.

Phylogenetic relationships and systematics of tapeworms of the family Davaineidae (Cestoda, Cyclophyllidea), with emphasis on species in rodents.

The present study aims at clarifying the poorly known phylogenetic relationships and systematics of cestodes of the family Davaineidae Braun, 1900 (Cyclophyllidea), primarily the genus Raillietina Fuhrmann, 1920 and of the subfamily Inermicapsiferinae (Anoplocephalidae) from mammals (mostly rodents, 31 new isolates) and birds (eight new isolates). Phylogenetic analyses are based on sequences of the large subunit ribosomal RNA gene (28S) and mitochondrial NADH dehydrogenase subunit 1 gene (nad1). The main phylogenetic pattern emerging from the present analysis is the presence of three independent lineages within the main clade of the subfamily Davaineinae, one of which is almost entirely confined to species from rodents and the other two show a mixture of species from birds and mammals. It is suggested that the major diversification of the main clade took place in birds, possibly in galliforms. The subsequent diversification included repeated host shifts from birds to mammals and to other birds, and from rodents to other mammals, showing that colonisation of new host lineages has been the main driver in the diversification of davaineine cestodes. It is also shown that all isolates of Inermicapsifer Janicki, 1910, mainly from rodents, form a monophyletic group positioned among Raillietina spp. in the "rodent lineage", indicating that the genus Inermicapsifer is a member of the family Davaineidae. This means that the subfamily Inermicapsiferinae and the family Inermicapsiferidae should be treated as synonyms of the Davaineidae, specifically the subfamily Davaineinae. Three additional genera generally included in the Inermicapsiferinae, i.e. Metacapsifer Spasskii, 1951, Pericapsifer Spasskii, 1951 and Thysanotaenia Beddard, 1911, are also assigned here to the Davaineidae (subfamily Davaineinae). Raillietina spp. were present in all three main lineages and appeared as multiple independent sublineages from bird and mammalian hosts, verifying the non-monophyly of the genus Raillietina and suggesting a presence of multiple new species and genera.

Tapeworms (Cestoda: Proteocephalidae) of the gars (Lepisosteidae), living fossils in America, including proposal of a new genus and a new species.

A new genus, Cordicestus, is proposed to accommodate proteocephalid tapeworms parasitising gars (Lepisosteiformes: Lepisosteidae) in North and Central America that were previously placed in the polyphyletic genus Proteocephalus Weinland, 1858. The new genus differs from other proteocephalid genera by the particular morphology of the scolex, which is small, protrudes apically but has no apical organ, and bears flat, heart-shaped (= cordis) suckers. In addition, the species of the new genus have an elongated cirrus sac with an almost straight internal vas deferens and wide, sinuous ventral osmoregulatory canals with secondary canals directed outwards. The type species of the new genus, Cordicestus singularis (La Rue, 1911) n. comb., is redescribed based on new material from the shortnose gar, Lepisosteus platostomus Rafinesque (type host), and the spotted gar, L. oculatus Winchell, in the United States. Cordicestus rafaeli n. sp. is described from the tropical gar, Atractosteus tropicus Gill, in Mexico. The new species differs from its relatives primarily by the presence of craspedote proglottids (acraspedote in other species) and some biometric features. All species of Cordicestus are revised, including unidentified specimens from A. tropicus and the Cuban gar A. tristoechus (Bloch and Schneider) in Nicaragua and Cuba, respectively, which may be new species, and a key to the identification of these taxa is provided. Molecular data available for two nominal species of the new genus indicate the possible existence of another species of Cordicestus in Lepisosteus in the USA.

Platybothrium yanae sp. nov. (Cestoda: Onchobothriidae) from the whitecheek shark, Carcharhinus dussumieri (Valenciennes), off southern Iran.

Platybothrium Linton, 1890 is a genus parasitizing sharks of the families Carcharhinidae and Sphyrnidae. No new species has been assigned to the genus in the 20 years since its last treatment. In the present study, a new species is described from the Persian Gulf, which is the second report of a species of Platybothrium in the Indian Ocean. Platybothrium yanae sp. nov. differs from P. auriculatum Yamaguti, 1952, P. cervinum Linton, 1890, P. tantulum Healy, 2003, and P. kirstenae Healy, 2003 in lacking, rather than having, an accessory piece between its hooks. This new species is distinguished from its other congeners by having a particular combination of features including its measurements, morphology, and meristic features, bringing the number of valid species in the genus to 11.

Cestode diversity in shrews from islands in the Sea of Japan and the Sea of Okhotsk.

A comparative analysis of taxonomic diversity on shrew cestodes among four islands in the Sea of Japan and the Sea of Okhotsk (Sakhalin, Kunashir, Hokkaido, and Moneron) was performed. Cestode species shared among the islands were identified and their host specificity was investigated. On Sakhalin Island, 33 species of the families Hymenolepididae, Dilepididae and Mesocestoididae were recorded in four shrew species (Sorex caecutiens, S. gracillimus, S. minutissimus and S. unguiculatus). In S. caecutiens, S. gracillimus, and S. unguiculatus on Kunashir Island, 22 species of the same families were found and, on Hokkaido Island, 23 species of the families Hymenolepididae and Dilepididae were recorded. On Moneron Island, three species of cestodes were registered in S. tundrensis. The Sakhalin-Hokkaido-Kunashir complex of shrew cestodes includes eastern-Palearctic, trans-Palearctic and endemic species. High endemism (~22%) of shrew tapeworms in the Sakhalin-Kunashir-Hokkaido Islands was noted as compared to continental territories. The different numbers of cestode species in S. unguiculatus (31), S. caecutiens (29), S. gracillimus (19) and S. minutissimus (1) were found. It was concluded that the cestodes species diversity of shrews of Sakhalin-Kunashir-Hokkaido depended primarily on the history of island formation, their modern physical and geographical features, the abundance of definitive and intermediate cestodes hosts and, to a lesser extent, on the size and remoteness of the islands from the mainland and the diversity of host species.

Molecular identification and prevalence of plerocercoid larvae (Cestoda: Diphyllobothriidae) in some commercial fish species from Peru.

Diphyllobothriosis, a fish-borne zoonosis in South America, is mainly caused by the Pacific broad tapeworm Adenocephalus pacificus Nybelin, 1931, a parasite of considerable concern in fishery resources due to its impact on public health. A new diphyllobothrid, Diphyllobothrium sprakeri Hernández-Orts et al. Parasites Vectors 14:219, 2021, was recently described from sea lions from the Pacific Coast, but marine fish acting as intermediate hosts are unknown. The objective of this study was to confirm the presence of plerocercoid larvae of Diphyllobothriidae Lühe, 1910 (Cestoda: Diphyllobothriidea) in nine fish species of commercial importance in Peru. Of a total of 6999 fish (5861 Engraulis ringens, 853 Sciaena deliciosa, 6 Sciaena callaensis, 171 Scomber japonicus, 40 Trachurus murphyi, 40 Ariopsis seemanni, 18 Merluccius peruanus, 5 Sarda chiliensis, and 5 Coryphaena hippurus), 183 were infected with plerocercoid larvae, representing a total prevalence of 2.61% and a mean intensity of 3.2. Based on mtDNA cox1 sequences of 43 plerocercoids, a phylogenetic analysis revealed that 41 belong to A. pacificus and two to D. sprakeri. These findings are first molecular data for D. sprakeri larvae, and the infections of E. ringens and T. murphyi by plerocercoid larvae represent the first records of intermediate/paratenic hosts for this species. Hence, the findings of the current study enhance our understanding of the presence of diphyllobothriid species in commercial fish from the Southeastern Pacific Ocean and their potential impact on seafood safety for local human populations.

Phylogeny of the cestode family Escherbothriidae (Cestoda: Rhinebothriidea) reveals unexpected patterns of association with skate hosts.

The rhinebothriidean tapeworm family Escherbothriidae has recently been expanded to include the genus Ivanovcestus , species of which parasitise arhynchobatid skates. Similarities in morphology and host associations between Ivanovcestus and Semiorbiseptum - a genus yet to be assigned to one of the families in the order Rhinebothriidea - led us to explore the possibility that Semiorbiseptum might also belong in the Escherbothriidae. Morphological similarities with Scalithrium ivanovae , Scalithrium kirchneri and Rhinebothrium scobinae , all of which also parasitise arhynchobatid skates, raised questions regarding the generic placements of these species. In addition, new collections from the skate Sympterygia brevicaudata revealed two new species that morphologically resemble species of Ivanovcestus . A combination of morphological and molecular data were used to assess the generic placement of the newly discovered species and refine our understanding of the membership of the family Escherbothriidae. Sequence data for the D1-D3 region of the 28S rDNA gene were generated de novo for 14 specimens of 7 rhinebothriidean species and combined with comparable published data to represent all 6 families in the Rhinebothriidea in the analysis. The phylogenetic tree resulting from maximum likelihood analysis strongly supports the inclusion of the genus Semiorbiseptum in the family Escherbothriidae. Our work also suggests that the skate-hosted species previously assigned to Scalithrium and Rhinebothrium are also members of Semiorbiseptum and that Ivanovcestus is a junior synonym of Semiorbiseptum . Six species are transferred to Semiorbiseptum , bringing the total number of species in the genus to ten. The diagnosis of Semiorbiseptum is amended to accommodate the additional species. A second species in the previously monotypic type genus of the family, Escherbothrium , is described. The diagnosis of the Escherbothriidae is amended to include the new and transferred species. This study underscores the importance of integrating morphological and molecular data in bringing resolution to cestode systematics. We believe our findings provide a robust foundation for future research into the evolutionary history and host associations of cestodes within the order Rhinebothriidea and beyond. These also highlight the importance of expanding our understanding of skate-hosted cestodes. ZooBank: urn:lsid:zoobank.org:pub:8052AFCA-5FBD-4430-95F4-0E5E368DEA3D.

Two proteocephalid cestodes in the fish Malapterurus electricus and Heterobranchus bidorsalis from Lake Nasser, Egypt: a morphological, molecular, and histopathological study.

Despite the importance of the electric catfish (Malapterurus electricus) and the African giant catfish (Heterobranchus bidorsalis) in the foodweb of Lake Nasser, Egypt, little is known about their diseases and parasitic fauna. This work describes, for the first time, cestodiasis in M. electricus and H. bidorsalis. Corallobothrium solidum and Proteocephalus sp. were identified morphologically and molecularly from M. electricus and H. bidorsalis, respectively. Using PCR, sequencing, and phylogenetic analysis, the two cestodes shared rRNA gene sequence similarities yet were unique and the two new sequences for the proteocephalid genera were submitted to the GenBank database. The prevalence of infection was 75% and 40% for the two fish species, respectively. Infections significantly increased in the summer and spring and were higher in female fish than in male fish. The intestine was the preferred site of the two adult cestodes. However, in the case of C. solidum some larval cestodes were found outside the intestine in between the skin and abdominal musculature, attached to the mesentery, and within intestinal tunica muscularis. Desquamation of the intestinal epithelium and inflammation at the site of infection in addition to congestion of the intestinal wall of the tapeworm infected fish were evident, indicating that C. solidum and Proteocephalus sp. impacted the infected fish. The larval stages of C. solidum attempted to penetrate the intestine and sometimes they were encircled within fibrous layers infiltrated with inflammatory cells. The infected fish's musculature was free of cestode infections. Preventive measures should be implemented to prevent the spread of infections.

Integrative taxonomy of metazoan parasites of the bluntnose sixgill shark Hexanchus griseus (Bonnaterre, 1788) in the Mediterranean Sea, with the resurrection of Grillotia acanthoscolex Rees, 1944 (Cestoda: Trypanorhyncha).

Appropriate diagnoses of parasites of apex marine predators are crucial to understand their biodiversity, host specificity, biogeography, and life cycles. Such diagnoses are also informative of ecological and biological characteristics of both host and environment in which the hosts and their parasites live. We here (i) investigate the parasite fauna of a bluntnose sixgill shark Hexanchus griseus (Bonnaterre, 1788) obtained from the Gulf of Naples (Tyrrhenian Sea), (ii) characterize molecularly all its metazoan parasites, and (iii) resurrect and report the main morphological features and phylogenetic position of Grillotia acanthoscolex, a cestode species previously synonymized with Grillotia adenoplusia. A rich parasite fauna represented by eight different taxa was found, including two monogeneans (Protocotyle grisea and Protocotyle taschenbergi), one digenean (Otodistomum veliporum), four cestodes (Crossobothrium dohrnii, Clistobothrium sp., G. acanthoscolex, and G. adenoplusia), and one copepod (Protodactylina pamelae). Sequencing of these samples accounts for an important molecular baseline to widen the knowledge on the parasitic fauna of bluntnose sixgill sharks worldwide and to reconstruct their correct food chains. The bluntnose sixgill shark was found to be a definitive host for all endoparasites found here, confirming that it occupies an apex trophic level in the Mediterranean Sea. The taxa composition of the trophic parasite fauna confirms that the bluntnose sixgill shark mostly feeds on teleost fish species. However, the occurrence of two phillobothrid cestodes (C. dohrnii and Clistobothrium sp.) suggests that it also feeds on squids. Finally, we emphasize the importance of using integrative taxonomic approaches in the study of parasites from definitive and intermediate hosts to elucidate biology and ecology of taxa generally understudied in the Mediterranean Sea.

First Report of Intestinal Cestode Infection in a Berylline Hummingbird (Saucerottia beryllina) in Mexico.

BACKGROUND: Up to now, five cestode species have been reported infecting five hummingbird species. To date, there have been no reports of cestode infections in hummingbirds in Mexico. METHODS: A Berylline hummingbird (Saucerottia beryllina) was found dead in a backyard at Toluca City, Mexico, and a window collision was assumed as the cause of death. The bird was preserved in 10% neutral buffered formalin for routine histological examination. RESULTS: At the histological study, liver parenchymal disruption was observed. This lesion could be the result of the assume collision. No lesions were observed in other tissues examined. Conspicuous cestode structures were observed in the lumen of the small intestine. Structure of cestodes, as revealed from histological sections, suggests their position in the genus Anonchotaenia Cohn, 1900 (family Paruterinidae). CONCLUSION: This is the first report of intestinal cestodosis in a Berylline hummingbird (S. beryllina) in Mexico.

Molecular identification of the rodent-borne pathogen Rodentolepis nana using the genetic markers of ITS-1, 18 S, and 28 S rDNA.

BACKGROUND: Rodentolepis nana (syn. Hymenolepis nana), the most common cyclophyllid tapeworm infecting rodents, is a well-studied gastrointestinal parasite in mice and belongs to the family Hymenolepididae. METHODS: The present study focuses on the molecular analysis for the nuclear genes (ITS-1, 18 S, and 28 S rDNA) used for the accurate recognition of the recovered Rodentolepis species. RESULTS: The annotated partial ITS-1, 18 S, and 28 S rDNA gene regions were deposited in GenBank (gbǀ MW310394.1, gbǀ MW327585.1, and gbǀ MW324479.1, respectively) and further used in the maximum likelihood method (ML) to clarify their genetic relationships at the species level. The interrogation sequence of R. nana was aligned and belonged to the family Hymenolepididae, in the same group as all Hymenolepis species, which were distinct from Cyclophyllidea cestodes, especially species belonging to Anoplocephalidae and Taeniidae. Sequence data support the paraphyly of Hymenolepis species. CONCLUSIONS: The phylogeny supports the availability of the ITS-1, 18 S, and 28 S rDNA genes as reliable genetic markers for evolutionary relationships.

Phylogenetic position of Acanthobothrium cleofanus (Cestoda: Onchoproteocephalidea) using molecular evidence.

Despite the large number of species described to date for the onchoprotepcephalid genus Acanthobothrium (207), only 16 named species have a genetic sequence. With this background, specimens of adult cestodes of the stingray Hypanus longus were collected off San Blas, Nayarit, and onchoproteocephalid larvae in the carangid fish Trachinotus rhodopus from Puerto Ángel, Oaxaca, both located on the Pacific coast of Mexico. The objective of this work is to investigate the phylogenetic position of these adults and larvae using nuclear ribosomal markers (18S rDNA and 28S rDNA). Morphologically, adult specimens were identified as Acanthobothrium cleofanus; larvae were identified only to family level. The phylogenetic position of both taxa was investigated based on the information of two nuclear molecular markers analyzed under Parsimony (PA) and Bayesian Inference (BI) methods. The newly generated sequences of A. cleofanus from Nayarit are identical to the sequences of several samples of Acanthobothrium sp. collected in the Mexican Pacific, which sequence are available in GenBank; DNA sequences obtained from onchoproteocephalid larva clearly place this taxon within Acanthobothrium but representing an independent lineage. In the resulting phylogenetic trees, Uncibilocularis okei was found nested within Acanthobothrium with an unstable position depending on the optimality criteria, indicating the need for more molecular analyzes with a greater number of species of both genera prior to define its phylogenetic relationships.

IMPORTANCE OF MUSEUM SPECIMENS: RESOLVING THE TAXONOMIC PUZZLE OF HUMAN-INFECTING BROAD TAPEWORMS DESCRIBED BY O. NYBELIN IN 1931, AND REDESCRIPTION OF THE TYPES OF ADENOCEPHALUS PACIFICUS.

To avoid confusions related to the resurrection of AdenocephalusNybelin, 1931 (Cestoda: Diphyllobothriidea), the type material of the Pacific broad tapeworm, Adenocephalus pacificusNybelin, 1931, which also infects humans, is morphologically characterized. Transverse protuberances on the ventral side of proglottids anterior to gonopores, which are a diagnostic feature of the genus, are illustrated for the first time. The present study supports the importance of a study of type material even in the 'molecular era' of taxonomy, where the value of morphology is often underestimated. It also points out the need for specimen deposition in publicly accessible collections.

Case Report: Human Bertiellosis-A Rare Cestode Infection in a South African Child.

Cestodes of Bertiella genus are parasites of nonhuman primates. We describe a rare case of human bertiellosis in South Africa: a 3-year-old girl with a 1-year history of rectal proglottid discharge and intermittent abdominal pain. After repeated failure with benzimidazole antihelminthic treatment, praziquantel proved successful.

The parasite Schistocephalus solidus secretes proteins with putative host manipulation functions.

BACKGROUND: Manipulative parasites are thought to liberate molecules in their external environment, acting as manipulation factors with biological functions implicated in their host's physiological and behavioural alterations. These manipulation factors are part of a complex mixture called the secretome. While the secretomes of various parasites have been described, there is very little data for a putative manipulative parasite. It is necessary to study the molecular interaction between a manipulative parasite and its host to better understand how such alterations evolve. METHODS: Here, we used proteomics to characterize the secretome of a model cestode with a complex life cycle based on trophic transmission. We studied Schistocephalus solidus during the life stage in which behavioural changes take place in its obligatory intermediate fish host, the threespine stickleback (Gasterosteus aculeatus). We produced a novel genome sequence and assembly of S. solidus to improve protein coding gene prediction and annotation for this parasite. We then described the whole worm's proteome and its secretome during fish host infection using LC-MS/MS. RESULTS: A total of 2290 proteins were detected in the proteome of S. solidus, and 30 additional proteins were detected specifically in the secretome. We found that the secretome contains proteases, proteins with neural and immune functions, as well as proteins involved in cell communication. We detected receptor-type tyrosine-protein phosphatases, which were reported in other parasitic systems to be manipulation factors. We also detected 12 S. solidus-specific proteins in the secretome that may play important roles in host-parasite interactions. CONCLUSIONS: Our results suggest that S. solidus liberates molecules with putative host manipulation functions in the host and that many of them are species-specific.

Genome of the fatal tapeworm Sparganum proliferum uncovers mechanisms for cryptic life cycle and aberrant larval proliferation.

The cryptic parasite Sparganum proliferum proliferates in humans and invades tissues and organs. Only scattered cases have been reported, but S. proliferum infection is always fatal. However, S. proliferum's phylogeny and life cycle remain enigmatic. To investigate the phylogenetic relationships between S. proliferum and other cestode species, and to examine the mechanisms underlying pathogenicity, we sequenced the entire genomes of S. proliferum and a closely related non-life-threatening tapeworm Spirometra erinaceieuropaei. Additionally, we performed larvae transcriptome analyses of S. proliferum plerocercoid to identify genes involved in asexual reproduction in the host. The genome sequences confirmed that the S. proliferum has experienced a clearly distinct evolutionary history from S. erinaceieuropaei. Moreover, we found that nonordinal extracellular matrix coordination allows asexual reproduction in the host, and loss of sexual maturity in S. proliferum are responsible for its fatal pathogenicity to humans. Our high-quality reference genome sequences should be valuable for future studies of pseudophyllidean tapeworm biology and parasitism.

New species of Guidus Ivanov, 2006 (Cestoda: Phyllobothriidea) from Bathyraja magellanica (Philippi) from the Patagonian Continental Shelf of Argentina.

Specimens representing two new species of Guidus Ivanov, 2006 were collected from the Magellan skate (Bathyraja magellanica [Philippi]) in the Patagonian Continental Shelf of Argentina, Southwestern Atlantic Ocean. Guidus francoi sp. n. and Guidus magellanicus sp. n. differ from their congeners by a particular combination of features, including type of bothridia, worm length, number of testes, and distribution of vitelline follicles. Guidus francoi sp. n. is distinguished from G. magellanicus sp. n. by having fewer proglottids, fewer testes and a higher ratio between the cirrus sac length and the proglottid width. The microthrix pattern of species of Guidus from the Southwestern Atlantic is described, based on specimens of G. francoi sp. n., Guidus magellanicus sp. n., and newly collected specimens of Guidus argentinense Ivanov, 2006. These three species share the presence of wide aristate gladiate spinitriches on the proximal bothridial surface, narrow gladiate spinitriches on the bothridial rim, and filitriches on the distal bothridial surface. The diagnosis of Guidus is revised to include several features exhibited by the new species (i.e., presence of bothridial indentations and bothridial stalks, distribution of vitelline follicles, and eggs grouped in cocoons). The discovery of G. francoi sp. n. and G. magellanicus sp. n. from B. magellanica increases the number of species of Guidus collected from batoids in the Southwestern Atlantic from one to three. The specificity exhibited by the species herein described reinforces the tight association between rays in the genera Guidus and Bathyraja.

Disentangling taxonomy of Biacetabulum (Cestoda, Caryophyllidea), parasites of catostomid fishes in North America: proposal of Megancestus gen. n. to accommodate B. carpiodi.

A new genus, Megancestus n. gen., is proposed to accommodate the caryophyllidean tapeworm Biacetabulum carpiodi Mackiewicz, 1969 from carpsuckers and quillback (Carpiodes spp.) in North America. This species is not closely related to other species of Biacetabulum Hunter, 1927 and is transferred to a newly erected genus. This new genus is typified by the possession of a small body (total length of 3.1-7.5 mm) with a scolex that bears a pair of large acetabulum-like loculi, two pairs of shallow lateral loculi, and a slightly convex apical disc, testes arranged in one or two layers, oval, thick-walled cirrus-sac, well-developed external seminal vesicle, separate gonopores, H-shaped ovary, few median vitelline follicles, and the uterus extending by a single loop anterior to the cirrus-sac. Megancestus differs from all Nearctic caryophyllidean genera (family Capingentidae), including Biacetabulum, by vitelline follicles dorsal to the ovary that connect the preovarian and postovarian vitelline fields. The most closely related Hunterella Mackiewicz et McCrae, 1962 differs by shape of the scolex (tholate, i.e., devoid of any loculi), dumbbell-shaped ovary and the uterus not extending anterior to the cirrus-sac. Megancestus carpiodi (Mackiewicz, 1969) n. comb. is the only species of the genus and it is a stenoxenous parasite, which has been found only in the river carpsucker (Carpiodes carpio-type host), quillback (Carpiodes cyprinus) and highfin carpsucker (Carpiodes velifer) (Catostomidae: Ictiobinae) in the lower and middle Mississippi basin.

The Proteocephalus species-aggregate (Cestoda) in cyprinoids, pike, eel, smelt and cavefish of the Nearctic region (North America): diversity, host associations and distribution.

Tapeworms (Cestoda) of the Proteocephalus-species aggregate from cyprinoids, pike, eel, smelt and cavefish in the Nearctic region (North America) are reviewed, based on a critical examination of newly collected and museum specimens. For some species neither new nor museum specimens were available and only literature data were used for these taxa. Two species occur in North American cyprinoids: (i) Nearctic Proteocephalus buplanensis Mayes, 1976 in Semotilus atromaculatus (Mitchill) in the upper Mississippi River and Hudson Bay drainage basins, and (ii) Holarctic P. torulosus (Batsch, 1786) (syns. P. ptychocheilus Faust, 1919; P. cobraeformis Haderlie, 1953; and Ophiotaenia critica Mpoame & Landers, 1981, new synonym), which occurs in Ptychocheilus spp. and other leuciscids in the western part of North America. Proteocephalus pinguis La Rue, 1911 is a specific parasite of pike (Esox spp.), which is briefly redescribed here to establish its diagnostic morphological characteristics because the original description was based on a mixture of at least two species. In addition to P. pinguis, pike serve as postyclic hosts of several species of the Proteocephalus-aggregate typical of other fish, such as bass, perch and whitefish, namely P. fluviatilis Bangham, 1925, P. pearsei La Rue, 1919 and P. longicollis (Zeder, 1800). Cavefish (Amblyopsidae) in North America harbour two endemic species, P. chologasteri Whittaker & Hill, 1968 from Chologaster agassizii Putman and P. poulsoni Whittaker & Zober, 1978 from Amblyopsis spelaea DeKay, which have never been found since their original description and their validity should be confirmed based on new collections and molecular data. Two other species of the Proteocephalus-aggregate, P. macrocephalus (Creplin, 1825), a parasite of eels (Anguilla spp.), and P. tetrastomus (Rudolphi, 1810) from smelt (Osmeridae), have circumboreal (Holarctic) distribution. Molecular data are available only for three of the seven species treated herein, but they do not form a monophyletic group.

Specific and non-specific cestodes of shrews (Eulipotyphla: Soricidae) in Europe with a description of Coronacanthus longicirrosus n. sp (Cestoda: Hymenolepididae).

This paper presents a review of host specificity among cestodes collected from Soricidae mammals in Europe and a revision of cestodes preserved in formalin in the collection of the East-Slovakian Museum in Kosice. The morphological re-examination of cestodes showed that cestodes found in non-specific hosts (Soricidae and Talpidae) were identified incorrectly. The majority of the redescribed species are specific to a particular host genus. Only one species of the Staphylocystis Villot, 1877 genus, which could be Staphylocystis brusatae (Vaucher, 1971) according to the number, shape and length of hooks, as originally described from Crocidura suaveolens (Pallas) from Switzerland, was found in a host of the genus Sorex Linnaeus. The host specificity of the majority of Hymenolepididae cestode species is stenoxenous, but this study of the collection and the critical review of cestodes from non-specific Soricidae hosts disclosed that representatives of the genus Staphylocystis are euryxenous. So, these cestodes are better adapted to spreading into new ecosystems. A new species from Neomys fodiens (Pennant) from Slovakia, Western Carpathian, belonging to the genus Coronacanthus Spassky, 1954, Coronacanthus longicirrosus n. sp., is described. The new species is easily distinguishable by the number of small rostellar hooks (12-18, 4-5 µm), hooks shape, long cirrus (70-86 µm) and the presence of the vaginal sphincter.