A new genus and species of Microphalloidea (Digenea), parasite of Peropteryx spp. (Chiroptera: Emballonuridae) from the Neotropical region of Mexico revealed by morphological and phylogenetic analyses.

The present study aims to describe a new genus and species of microphalloid digenean parasite of two species of bats of the genus Peropteryx from the Mexican Neotropics (in the states of Chiapas and Yucatán). Morphological and molecular data (28s rDNA ribosomal gene sequences) were used to study Digeneans. Sagittatrema zutzi gen. nov. sp., nov., is diagnosed morphologically by having a sagittiform body, a genital pore in the midline of the body, posterior to the ventral sucker, and a cirrus sac running through much of the diameter of the ventral sucker. The nine sequences generated from the 28S rDNA gene were used to examine the phylogenetic affinities of this new taxon within the superfamily Microphalloidea Ward, 1901, using Maximum Likelihood and Bayesian Inference analyses. Both analyses resulted in trees with similar topologies and formed a well-supported clade (Bt = 100; pp = 1) with the Sagittatrema sequences. Because of the new genus's phylogenetic position and that some sister families to the proposed taxa, like Pleurogenidae and Prosthogonimidae, are polyphyletic, we prefer to consider Sagittatrema as a genus incertae sedis within Microphalloidea. A full systematic review of microphalloids is needed to confirm their phylogenetic position.

Nuclear ribosomal transcription units in Asian Paragonimus species (Paragonimidae: Platyhelminthes): genetic characteristics, polymorphism, and implications for intersuperfamilial phylogeny.

The entire transcribed sequences (from the 5' terminus of 18S to the 3' terminus of 28S rRNA genes) of the ribosomal transcription units (rTU*) of five Asian Paragonimus species were obtained and characterized. The rTU* length was 7661 bp for P. heterotremus (LC strain, Vietnam), 7422 bp for P. iloktsuenensis (Amami strain, Japan), 6932 bp for P. skrjabini miyazakii (OkuST1 strain, Japan), 7422 bp for P. ohirai (Kino strain, Japan), and three strains of P. westermani: 8616 bp (Megha strain, India), 7292 bp (Bogil strain, South Korea), and 7052 bp (QT2 strain, Vietnam) without intergenic spacer region (IGS). All seven Asian Paragonimus strains' genetic characteristics were described, including the length of individual genes/regions, repeat polymorphism, base composition, and skewness. To investigate the superfamilial relationships in the Xiphidiata, with a focus on the Troglotrematoidea and its associated superfamilies, we used the PhyML software package to create three comprehensive maximum-likelihood phylogenies. The datasets used were 83 concatenated 28S + 18S, 83 single complete 18S, and 157 single, partial 28S rDNA sequences, respectively, from entire rTUs and/or accessible ribosomal sequences of the same species from the suborders Xiphidiata, Echinostomata, and Haplosplanchnata, with a Schistosoma sequence as an outgroup. Three phylogenetic trees revealed that Echinostomata and Haplosplanchnata are monophyletic, while Xiphidiata is polyphyletic and contains the monophyletic Troglotrematoidea. The concatenated 18S + 28S and single 18S phylogenies revealed well-bootstrap supported seven superfamilies (Troglotrematoidea, Haploporoidea, Gorgoderoidea, Brachycladioidea, Microphalloidea, Plagiorchioidea, and Opecoeloidea) that are monophyletic in the Xiphidiata. The Haploporoidea was a basal superfamily nested close to the Gorgoderoidea and Troglotrematoidea and was not supported as a distinct suborder Haploporata. Six of seven xiphidiatan superfamilies were monophyletic in the partial 28S phylogeny, with the exception of Opecoeloidea, which was separated into two different subclades: Opecoelidae and Stenakridae/Zdzitowieckitrematidae. The monophyletic Haploporoidea/Haploporata was separated from the Gorgoderoidea associates and placed in a marginal group in Xiphidiata. There were two notable clusters in the Paragonimidae: mixed-Paragonimus, which included a fairly compact group of P. heterotremus strains, and P. westermani/siamensis, which was divided into geographical/country strain groups. In conclusion, combined ribosomal rDNA sequences were more effective than single rDNA markers in resolving interfamilial and familial relationships. The ribosomal datasets presented here will be useful for taxonomic reassessment, as well as evolutionary and population genetics research in the Troglotrematoidea and other superfamilies in the Xiphidiata and the class Trematoda.

Assessing the diversity of freshwater fish trematodes from Laguna Escondida, Los Tuxtlas tropical rainforest, Mexico, using morphology and 28S rDNA sequences as barcodes.

Despite a great effort made for almost 90 years, the diversity of freshwater fish trematodes in Mexico is still far from being fully known. The addition of molecular data to the description of trematode diversity in the last two decades added the potential to establish more robust species limits and a more accurate biodiversity estimation, but also led in some instances to the recognition of cryptic species complexes. Here, we used sequences of the large subunit of the nuclear ribosomal gene (28S rRNA) as barcodes, and morphological data, to assess the diversity of freshwater fish trematodes from a lake within a tropical rainforest. Eighty freshwater fish specimens of eight species were studied, and 120 trematode specimens were collected. Morphologically, specimens were allocated into nine genera; molecular phylogenetic analyses along with sequence divergence data provided evidence for recognising 11 trematode taxa, six adults and five metacercariae; six of them were identified to species level. Geographical distribution and host association patterns are briefly discussed for each trematode taxa.

New record and phylogenetic assessment of Apopharynx bolodes (Braun, 1902) (Digenea: Psilostomidae), a parasite of Eurasian Coot Fulica atra Linnaeus, 1758 (Aves: Rallidae).

Phylogenetic studies of aberrant species are of considerable scientific interest because their taxonomic rank in traditional systems based on morphological characters is not infrequently overestimated. Apopharynx bolodes (Braun, ) is one of the few psilostomid digeneans devoid of the pharynx. This is considered a sufficient basis for assigning it and similar species to the subfamily Apopharynginae. We found A. bolodes in Fulica atra Linnaeus, 1758 from Belarus, described it morphologically, and genotyped it by the 28S rRNA gene and the ITS2 region. It is the first molecular data on A. bolodes and the first record of this digenean species in Belarus. The phylogenetic analysis based on partial sequences of the 28S rRNA gene showed that A. bolodes is closely related to the Sphaeridiotrema spp. (Sphaeridiotrematinae). However, this phylogenetic inference has not received yet support with data on the ITS2 region.

Systematics of Pseudocavisoma (Acanthocephala: Echinorhynchida): assessment of familial affiliation, establishment of a new species, and complementary redescription of the type species based on syntypes.

The familial affiliation of the so-far-monotypic palaeacanthocephalan genus Pseudocavisoma Golvan & Houin, 1964 has solely been based on morphological characteristics, lacking nucleotide sequence data. In this paper, we assess the phylogenetic position of the genus with a dataset consisting of partial sequences of the mitochondrial cytochrome c oxidase subunit I, and the nuclear 18S and 28S rRNA genes for 37 species of palaeacanthocephalans available in public databases along with the ones determined from the new species Pseudocavisoma setoense sp. nov., herein established with specimens collected from the intestine of the pearl-spot chromis Chromis notata (Temminck & Schlegel, 1843) obtained in the Seto Inland Sea, Japan. Our results suggested that Pseudocavisoma should be placed in Micracanthorhynchinidae Yamaguti, 1963, rather than in Cavisomatidae Meyer, 1932 as had been considered by previous authors. Because Micracanthorhynchinidae has been regarded synonymous with Rhadinorhynchidae Lühe, 1912 since 1985, we re-validate the former taxon while providing an amended diagnosis for it. Pseudocavisoma setoense sp. nov. can be distinguished from the sole congener Pseudocavisoma chromitidis (Cable & Quick, 1954) by the distributional pattern and the size of spines on the trunk. We provide a partial morphological redescription of the latter species based on syntypes of Cavisoma chromitidis Cable & Quick, 1954. We also provide an amended diagnosis for Pseudocavisoma to accommodate P. setoense sp. nov.

Morpho-molecular characterization and phylogenetic relationships of Encotyllabe percussa n. sp. (Monogenea: Capsalidae) from the spangled emperor Lethrinus nebulosus (Teleostei, Lethrinidae).

Encotyllabe percussa n. sp. is proposed based on morphology and DNA sequences analysis of ribosomal (18S, 28S) and mitochondrial (COI) gene fragments. Encotyllabe percussa n. sp. was found infecting the spangled emperor Lethrinus nebulosus (n = 75) with higher prevalence from Dibba, Musandam (Gulf of Oman) than in Dhofar Salalah (Indian Ocean), Oman (p = 0.03). The general morphology of E. percussa n. sp. resembles E. caballeroi, E. chironemi and E. spari, which exhibit pre-equatorial testes. However, E. percussa n. sp. shows unique morphological characteristics distinguishing from congeneric species: the large hamuli bear notch allocated externally between the first half proximal of the root, and the small hamuli exhibit semicircular shape with undivided roots. Phylogenetic relationships within the Encotyllabe genus remain unresolved. However, the tree topology with the 28S showed overall consistency with the principal component analysis arrangement (PCA) derived from the morphological analysis. Which showed that the large and small hamuli, marginal hooks, ovary, testes (length and width) and peduncle are currently the most important morphological traits within the genus. Cytochrome c oxidase subunit I (COI) gene fragment showed high interspecific genetic divergence adding unambiguous resolution to discriminate/designate species identity. Interrelations within the genus support the identity of Encotyllabe percussa as a new species. This is the first species characterized with three gene fragments, the second congeneric species described in L. nebulosus and the first recorded in Oman.

First report of white piedra caused by Cutaneotrichosporon debeurmannianum.

Piedras are small nodules found on the hair shafts. White piedra was initially described as caused by Trichosporon beigelii, which was later reclassified in several species. We describe the first case of white piedra caused by Cutaneotrichosporon debeurmannianum. Affected hairs were examined in natura with scanning electron microscopy, after gold metallization. The typical whitish cerebriform creamy colony was obtained in Sabouraud medium. Fungal genomic DNA extracted from cultures and locus was amplified with the NL1/NL4 primer pair from the D1/D2 region of the large ribosomal subunit (LSU) of 28S rRNA. With scanning electron microscopy, nodules are easily identified surrounding the hair shaft; with high magnifications, rounded structures adhered to each other were identified. Comparison of the nucleotide sequences of IMT-1703 Cutaneotrichosporon debeurmannianum revealed 99.6% similarity with the 28S large ribosomal unit rDNA sequence. This case of white piedra was caused by Cutaneotrichosporon debeurmannianum.

A window on remarkable cryptic diversity of the Merodon planifacies subgroup (Diptera: Syrphidae) in the Afrotropical Region.

The genus Merodon Meigen (Diptera: Syrphidae) is one of the most species-rich hoverfly genera distributed across the Palaearctic and Afrotropical regions. In the Palaearctic, the genus Merodon boasts 195 described species, while its Afrotropical region pales in comparison, with a mere 17 species documented thus far. As a result of 8 years of fieldwork conducted in the Republic of South Africa, in this paper, we present the description of 11 new species for science with a description of immature stages for 2 species, which increases the diversity of this genus in the Afrotropical region by remarkable 39%. These revelations are based on integrating morphology, molecular analysis (COI gene and 28S rRNA) and geometric morphometry. All described species belong to the Merodon planifacies subgroup, the Merodon desuturinus lineage and, within that, to the Afrotropical Merodon melanocerus group. Additionally, we provide an illustrated key to 15 species belonging to the subgroup, a detailed discussion on relevant taxonomic characters, a morphological diagnosis, a distribution map and clarification of the association between M. capi complex and host plants from the genus Merwilla.

Morphological and molecular characterisation of two new species of Rhipidocotyle (Digenea: Bucephalidae Poche, 1907) from Sphyraena putnamae Jordan & Seale in Mozambique.

Species-level delineation of digenetic trematodes is complex and can be best achieved by integrative taxonomy using both genetic characterisation and morphological analysis. Two new Bucephalidae species of the genus Rhipidocotyle Diesing, 1858 are described here based on specimens collected from the intestine of Sphyraena putnamae Jordan & Seale following this approach. Adults of R. siphonyaka n. sp. and R. nolwe n. sp. possess tentacles and a tegument with scales. They are distinguished from their congeners by the arrangement of the digestive structures, the extent of the uterus relative to vitelline fields, and the arrangement of the reproductive structures. Rhipidocotyle siphonyaka n. sp. differs from R. nolwe n. sp. in having the pharynx and mouth positioned in the pre-uterine field, tandem testes, longer body length, and shorter pre-vitelline and post-testicular distance. Rhipidocotyle siphonyaka n. sp. differs from its congeners in having a tube-like intestinal caecum, pharynx and mouth opening positioned in the pre-vitelline field. Rhipidocotyle nolwe n. sp. appears to be similar, morphologically and morphometrically, to Rhipidocotyle khalili (Nagaty, 1937). Despite their similarities, R. nolwe n. sp. has a shorter body length and egg size. Moreover, the molecular analysis of 28S and ITS rDNA fragments indicate that R. siphonyaka n. sp. and R. nolwe n. sp. are closely related phylogenetically but distinct from one another and other Bucephalidae for which molecular data are available.

Never ending diversity: two new species of the genus Allocreadium (Digenea: Allocreadiidae) including new keys to the genus.

Two new species of the genus Allocreadium were isolated from the intestines of the Lake minnow Rhynchocypris percnura caught in the backwater of the Komissarovka River in the South of the Russian Far East. The morphology of A. anastasii n. sp. corresponds to that of Allocreadium sp. from Lake Khar (Mongolia) and Allocreadium sp. Belous, 1952 from the Primorsky region of Russia except for the preacetabular anterior border of the vitelline follicles in A. anastasii n. sp. from the Komissarovka River vs. at anterior half of ventral sucker in Allocreadium sp. Genetic analysis revealed the identity of A. anastasii n. sp. to Allocreadium sp. 1 from the Nezhinka River and Lake Khar. Allocreadium macrolecithum n. sp. was differentiated from Palaearctic Allocreadium spp. by having the following features: respectively large vitelline follicles extending from posterior extremity to anterior margin of the ventral sucker; relatively short caeca reaching the border of middle and posterior thirds of hindbody; and small testes in the middle of hindbody. Interspecific genetic p-distances between Allocreadium spp. were 0.16-7.23% in 28S gene and 18.62-31.54% in Cox1 mtDNA gene. In the phylogenetic tree reconstructed with Maximum parsimony and Bayesian Inference methods, A. anastasii n. sp. and A. macrolecithum n. sp. were nested into different species groups of the genus Allocreadium - sister to A. khankaiense and A. bursense, respectively. Modified dichotomous keys were prepared for 31 Palaearctic species of Allocreadium including A. crassum, A. dogieli, A. papilligerum, A. bursense, A. anastasii n. sp., and A. macrolecithum n. sp.

Wandering the taxonomic mine-field: the Podocotyle species complex (Digenea: Opecoelidae).

This study focuses on the opecoelid genus Podocotyle, particularly the species in the northern European seas (White, Barents and Pechora), with additional data from few isolates from the Far East. The research combines molecular analyses (28S, 5.8S+ITS2 rDNA, and cox1 mtDNA) and morphological examinations. Molecular analyses suggested that there are most likely four species of Podocotyle in the northern European seas and three more in the Far East. Morphological redescriptions are provided for three northern European species: P. atomon, P. reflexa, and P. odhneri, with the latter recognized as a valid species. The study also verified the life cycle of P. atomon and identified Lacuna vincta (Littorinidae) as the first intermediate host for P. reflexa. In the Sea of Okhotsk, L. turrita is the first intermediate host for two apparently undescribed Podocotyle species. The results also highlight the morphological variability of P. atomon, emphasizing the need for an integrative approach in the taxonomy and biodiversity studies.

Morpho-molecular characterization of phoma-like fungi from Morus alba in northern Thailand; a novel species (Boeremia albae) and a new host record (B. maritima).

Boeremia was established to accommodate phoma-resembling fungi. Its species occur in terrestrial ecosystems as endophytes, saprobes and pathogens, except one species reported from a marine ecosystem. Boeremia species are characterized by hyaline, thin-walled, and aseptate (occasionally 1(-2)-septate) conidia that are variable in shape, and hyaline, straight or slightly curved, thick-walled, and 1-septate ascospores that are usually constricted at the septum. In the past, host associations were used to delimit Boeremia species. However, since Boeremia taxa have overlapping morphological characters and are cryptic, it renders taxonomic identification arduous. Therefore, the use of other approaches including multi-gene phylogenetic analyses are imperative. Recommended DNA markers for species delineation are the internal transcribed spacer (ITS, nuclear rDNA consisting of ITS1-5.8S-ITS2) and large subunit (28S, D1-D2 domains of nuclear 28S rDNA) loci, and the genes for actin (ACT1), beta-tubulin (TBB1), RNA polymerase 2 (RPB2) and translation elongation factor 1α (TEF1). Here, we applied morphological and molecular phylogenetic analyses to establish a new taxon (B. albae), and a new host and geographical record for B. maritima associated with leaf spots of Morus alba (Moraceae) in northern Thailand. By providing sequence data for three additional gene regions, our phylogenetic analyses impart a stable phylogenetic placement of the ex-type strain of B. maritima, as illustrated. This is the first study that reports Boeremia species from M. alba, and B. maritima from a terrestrial habitat.

Species of Annulotrema (Monopisthocotylea, Dactylogyridae) parasitising African tetras (Characiformes, Alestidae) in the Phongolo River, South Africa with the description of four new species.

Species of Alestidae are known to be parasitised by dactylogyrid monogeneans representing three genera, Afrocleidodiscus Paperna, 1969, Annulotrema Paperna & Thurston, 1969, and Characidotrema Paperna & Thurston, 1968. The objective of the present study was to investigate the species diversity of Monopisthocotylea of African tetras from the Lower Phongolo River and floodplain in South Africa. Four new and two previously described species of Annulotrema were identified from the gills of three species of African tetras, Brycinus imberi, Hydrocynus vittatus, and Micralestes acutidens. The collected parasites were studied using two complementary approaches: morphology of hard sclerotised structures, and molecular markers using rDNA sequence data (28S rDNA, 18S rDNA, and ITS1). Three new species, Annulotrema arcum n. sp., Annulotrema caputfemoris n. sp., and Annulotrema strepsiceros n. sp., were described from B. imberi and one species, Annulotrema retortum n. sp., from M. acuditens. Two previously described species, Annulotrema pikoides Guégan, Lambert and Birgi, 1988 and A. pseudonili Kicinjaová and Rehulková, 2017, were newly recorded from H. vittatus in South Africa. Annulotrema arcum n. sp. and A. caputfemoris n. sp. share similar male copulatory organ morphologies, suggesting a close phylogenetic relationship as sister taxa. Despite weak nodal support, A. strepsiceros n. sp. shows morphological congruence with the former two species, reinforcing their molecular linkage. The present study shows a critical need for the exploration of monopisthocotylean diversity and the paucity of available molecular data of representatives from this group.

Title: Espèces d'Annulotrema (Monopisthocotylea, Dactylogyridae) parasitant des tétras africains (Characiformes, Alestidae) dans la rivière Phongolo, en Afrique du Sud, avec description de quatre nouvelles espèces. Abstract: Les espèces d'Alestidae sont connues pour être parasitées par des monogènes Dactylogyridae représentant trois genres, Afrocleidodiscus Paperna, 1969, Annulotrema Paperna & Thurston, 1969 et Characidotrema Paperna & Thurston, 1968. L'objectif de la présente étude était d'examiner la diversité des espèces de Monopisthocotylea des tétras africains du cours inférieur de la rivière Phongolo et de sa plaine inondable en Afrique du Sud. Quatre nouvelles espèces d'Annulotrema et deux espèces déjà décrites ont été identifiées à partir des branchies de trois espèces de tétras africains, Brycinus imberi, Hydrocynus vittatus et Micralestes acutidens. Les parasites collectés ont été étudiés en utilisant deux approches complémentaires, la morphologie des structures sclérifiées et les marqueurs moléculaires utilisant des données de séquence d'ADNr (ADNr 28S, ADNr 18S et ITS1). Trois nouvelles espèces, Annulotrema arcum n. sp., Annulotrema caputfemoris n. sp. et Annulotrema strepsiceros n. sp., ont été décrites chez B. imberi et une espèce, Annulotrema retortum n. sp., chez M. acuditens. Deux espèces précédemment décrites, Annulotrema pikoides Guégan, Lambert et Birgi, 1988 et A. pseudonili Kicinjaová et Rehulková, 2017, ont été nouvellement répertoriées chez H. vittatus en Afrique du Sud. Annulotrema arcum n. sp. et A. caputfemoris n. sp. partagent des morphologies similaires de l'organe copulateur mâle, suggérant une relation phylogénétique étroite de taxons frères. Malgré un faible support nodal, A. strepsiceros n. sp. présente une congruence morphologique avec les deux premières espèces, renforçant leur lien moléculaire. La présente étude montre qu'il est essentiel d'explorer la diversité des Monopisthocotylea et que les données moléculaires disponibles sur les représentants de ce groupe sont rares.

TRICHINELLA MURRELLI POZIO AND LA ROSA, 2000 IN A GRAY FOX (UROCYON CINEREOARGENTEUS) FROM PENNSYLVANIA: A NEW HOST RECORD FOR THIS ZOONOTIC NEMATODE.

Trichinella murrelli Pozio and La Rosa, 2000, is the primary sylvatic trichinellid encountered in temperate North America. During a survey for Sarcocystis in wild canids, a single worm matching the morphology of encapsulated Trichinella was observed in a muscle tissue squash from a gray fox male originating from Pennsylvania. The worm was photographed and then separated from the host tissue by artificial digestion, and genomic DNA was extracted from the worm. This DNA was subjected to species-specific multiplex PCR and short-read genomic sequencing. The banding pattern of the multiplex PCR indicated that the worm was T. murrelli, and the sequence of the mitochondrial Cytochrome c oxidase 1 gene and the ribosomal 18S ribosomal RNA, Internal Transcribed Spacer 1, 5.8S ribosomal RNA, Internal Transcribed Spacer 2, and 28S ribosomal RNA confirmed the diagnosis. This is the first report of T. murrelli in gray foxes that includes assays for assigning parasite species. This report confirms suspected data from surveys conducted over 30 yr ago and establishes a new host record for T. murrelli.

First genetic characterisation and phylogenetic position of Aplectana hylambatis (Nematoda: Cosmocercidae), infecting Pithecopus azureus (Anura: Hylidae) in the Brazilian Pantanal.

Aplectana hylambatis (Baylis, 1927) is a widespread nematode in South America that infects different species of anurans from different families. Although the morphology of this species shows intraspecific variations and is well studied, A. hylambatis does not have genetic characterisation. Therefore, the present study aimed to provide the first genetic characterisation of this parasite, based on 18S and 28S rDNA sequences, as well as to evaluate its phylogenetic position in the family Cosmocercidae. The present specimens showed no major morphological variations and were assigned to A. hylambatis mainly based on the shape of spicules and the presence of mamelon-like structures slightly anterior to the vulva. The genetic characterisation confirmed the close relationship between A. hylambatis and other cosmocercids, and the 28S sequences were more informative for phylogenetic reconstruction, especially for those relationships at higher and intermediate levels. Aplectana hylmabatis was in a basal position within a clade formed by other congeners and species of Cosmocerca. The geographic origin may have influence in the divergence process of Aplectana spp. and genus was non-monophyletic and closely related to Cosmocerca, similar to previous findings. The present results will be useful for future studies on the phylogeny of Cosmocercidae, since several genera and species in this family still lack genetic characterisation. Furthermore, the 28S sequences can be useful in genetic studies of A. hylambatis populations, since this species appears to have phenotypic variations.

A NEW SPECIES OF ACANTHOBOTHRIUM (CESTODA: ONCHOPROTEOCEPHALIDEA), PARASITE OF THE GIANT ELECTRIC RAY NARCINE ENTEMEDOR JORDAN AND STARKS, 1895 (BATOIDEA: TORPEDINIFORMES) FROM MEXICO.

Spiral valves from specimens of the giant electric ray Narcine entemedor Jordan & Starks, 1895 were examined in search of tapeworms at 2 localities of the Mexican tropical Pacific Ocean. Acanthobothrium oceguerai n. sp. is described herein based on material from Ventanilla, Oaxaca and from Acapulco Bay, Guerrero. The new species is a category 6 species, distinguished by being apolytic, retaining proglottids on the strobila until they are gravid, having strobila of 166-322 proglottids, having a small scolex and very long bothridia relative to the scolex, and having abaxial prongs that are short and thin in comparison to the axial prongs, which are longer and more robust. Acanthobothrium oceguerai n. sp. can be differentiated from other members of category 6 by the hooks, which are shorter, more robust, and smaller than those of the other members of this category. The phylogenetic analysis based on the 28S rRNA locus placed Acanthobothrium oceguerai n. sp. as sister to an unidentified species of larval Acanthobothrium from Philadelphia, Pennsylvania. In addition, sequences of the mitochondrial cytochrome oxidase subunit I gene and nuclear 18S rDNA were generated to provide support for future taxon sampling. Acanthobothrium oceguerai n. sp. is the fifth species of cestode reported from N. entemedor in the tropical eastern Pacific.

New insights into the systematics of Cyclocoelidae (Trematoda: Echinostomatoidea) based on novel morphological and molecular data, with description of a new species and a new genus.

In light of the morphological and molecular data for cyclocoelids observed from the air sacs of Mareca strepera (Linnaeus) (Anatidae, Anseriformes) caught in the southern region of the Russian Far East, we suggest new insights into the systematics of the family Cyclocoelidae. A comparative morphological and phylogenetic analyzes revealed that new cyclocoelids represented the new genus and species Paracyclocoelum lobatum. Based on the 28S rRNA gene fragment we showed the significant genetic divergence of P. lobatum from the type species of the type genus for the family, Cyclocoelum mutabile (Zeder, 1800) Brandes, 1892 and along with the confusing morphological similarity by the prepharyngeal position of the genital pore it most likely indicate homologous development of the reproductive system of Paracyclocoelum and Cyclocoelum. Here, we provide a new dichotomous key for five cyclocoelid genera from the subfamily Cyclocoelinae including Paracyclocoelum n. g. The new genus Paracyclocoelum had sister relationship to the cyclocoelin genus Circumvitellatrema. Based on the polyphyletic interrelationships of Cyclocoelum and Circumvitellatrema the Cyclocoelinae were assigned with the status sensu lato.

REDESCRIPTION OF HASSALSTRONGYLUS ADUNCUS CHANDLER, 1932 (NEMATODA: HELIGMONELLIDAE), WITH THE DESCRIPTION OF A NEW SPECIES OF THE GENUS AND THEIR PHYLOGENETIC POSITION WITH OTHER HELIGMOSOMOIDEA TRAVASSOS, 1914.

ABSTRACT: Hassalstrongylus Durette-Desset, 1971 (Nematoda: Heligmonellidae), includes 19 species that are distributed from the southwestern United States to central-western Argentina. Hassalstrongylus aduncus is a parasitic nematode of rodents from the subfamilies Arvicolinae, Murinae, and Sigmodontinae, and has been recorded from southern Virginia and Oklahoma to Costa Rica. This species was described by Chandler in 1932; the morphology of the synlophe was not included. Subsequently, in 1972, Durette-Desset described only the synlophe of the middle region of the body in both sexes. Despite its wide geographical distribution, to date, there has been no redescription that includes information complementary to the morphology of the synlophe, such as a study of the body surface or a molecular phylogenetic analysis. We reevaluated the morphology of some specimens that were presumably similar to H. aduncus parasite of Sigmodon sp. from Jalisco, Mexico, and it was determined that these corresponded to an undescribed species of the genus. Herein, we present a redescription of H. aduncus parasite of Sigmodon toltecus from Hidalgo, Mexico, with morphological traits such as the excretory pore, deirids, and ovijector, and provide a description of the synlophe in the anterior and posterior regions of both sexes and include scanning electron microscopy images. Hassalstrongylus geolayarum n. sp. is differentiated from H. aduncus by the number of ridges in the middle region of the body (23 vs. 21), as well as proportions between some traits of males and females such as total length/spicule length, total length/gubernaculum length, total length/length of the esophagus and total length/distance of the vulva and the size of the eggs (42 vs. 58 µm). Phylogenetic analysis is based on partial sequences of the nuclear ribosomal internal transcribed spacer region (ITS1 + 5.8S + ITS2) of the rDNA, using the maximum-parsimony, maximum-likelihood, and Bayesian inference methods revealed the close relationship of H. aduncus + H. geolayarum n. sp. within the Heligmosomoidea and confirmed the placement of the Hassalstrongylus monophyletic clade well-supported within Heligmonellidae. The new species presented a genetic divergence of 3.4-3.8% relative to H. aduncus. This is the first species of the genus described in Mexico. Presumably, there are more species not yet described throughout the geographic range of H. aduncus. A taxonomic review and molecular phylogenetic analysis are required in which more species and genes are analyzed in Heligmosomoidea to confirm the status of the nonmonophyletic groups recovered here.

Trematode species diversity in the faucet snail, Bithynia tentaculata at the western edge of its native distribution, in Ireland.

Trematodes and their snail hosts have developed intimate parasite-host associations, with snails supporting a diverse and often species-specific trematode fauna. In the faucet snail, Bithynia tentaculata (Caenogastropoda, Littorinimorpha), a unique trematode fauna has been recorded recently. However, knowledge of the exact species identity, phylogenetic relationships, and geographical distribution remains limited as many of the species belong to groups with unclear or controversial taxonomical assignment. To contribute to our knowledge of the trematodes, we investigated the trematode fauna of B. tentaculata by examining a total of 556 snails from lakes in County Galway, Ireland. Using an integrative taxonomic approach including DNA sequence data analyses (28S rRNA gene, ITS1-5.8S-ITS2, ITS2, cox1, nad1) and morphological tools (taxonomical drawings and measurements), we identified nine trematode species of seven families, with seven species occurring as cercariae (Cyathocotyle prussica, Lecithodendrium linstowi, Lecithodendrium sp., Asymphylodora progenetica, Sphaerostoma bramae, Metorchis xanthosomus, and Notocotylus sp.) and three species occurring as metacercariae (A. progenetica, Parasymphylodora parasquamosa, and Sphaeridiotrema sp.). Except for S. bramae, all are new species records for Ireland and provide the most western distribution of these trematodes in Europe. The trematode species recorded are known to use a wide range of definitive hosts and have a wide geographical distribution; among them are species members of genera that are zoonotic (Metorchis) and pathogenic to wildlife (Cyathocotyle, Sphaeridiotrema, and Notocotylus). There remains an ongoing need for precise identification of the trematode species to ensure that wider ecological contexts are correctly understood and biodiversity and disease threats can be accurately evaluated.

Alobophora sandrae n. gen. n. sp. (Digenea: Caballerotrematidae) infecting Arapaima gigas sensu lato (Osteoglossiformes: Arapaimidae) with a revision of Caballerotrema, key to Caballerotrematidae, and updated phylogeny.

We propose and describe Alobophora sandrae Cajiao-Mora & Bullard n. gen., n. sp. (Digenea: Caballerotrematidae) for specimens we collected from arapaima, Arapaima gigas sensu lato (Osteoglossiformes: Arapaimidae) in the Amazon River near Leticia, Colombia. Alobophora differs from Caballerotrema Prudhoe, 1960 by lacking head collar projections and by having clustered corner spines and a narrow head collar (4-5× wider than pharynx), whereas Caballerotrema has head collar projections, lacks clustered corner spines, and has a broad head collar (7-8× wider than pharynx). We reassign Caballerotrema annulatum (Diesing, 1850) Ostrowski de Núñez & Sattmann, 2002 to the new genus, as Alobophora annulata (Diesing, 1850) Cajiao-Mora and Bullard n. comb., and provide a supplemental description of Caballerotrema brasiliense Prudhoe, 1960 based on specimens we collected from arapaima. We also examined the holotype and a paratype of Caballerotrema piscicola (Stunkard, 1960) Kostadinova & Gibson, 2001 and concluded that C. piscicola is a junior subjective synonym of C. brasiliense. Our 28S phylogeny recovered A. sandrae sister to A. annulata, with that clade sister to a clade comprising C. brasiliense and an innominate species of Caballerotrema. Caballerotrematidae was recovered sister to Echinostomatidae. We also provide a dichotomous key to caballerotrematids based on head collar projections, corner spine arrangement, proportional pharynx and head collar breadth, testes shape and arrangement, body surface spine shape and distribution, vitellarium distribution, and abundance of prostatic cells.

Title: Alobophora sandrae n. gen. n. sp. (Digenea : Caballerotrematidae) infectant Arapaima gigas sensu lato (Osteoglossiformes : Arapaimidae) avec une révision de Caballerotrema, une clé des Caballerotrematidae et une phylogénie mise à jour. Abstract: Nous proposons et décrivons Alobophora sandrae Cajiao-Mora & Bullard n. gen., n. sp. (Digenea : Caballerotrematidae) pour les spécimens que nous avons collectés chez l'arapaïma, Arapaima gigas sensu lato (Osteoglossiformes : Arapaimidae) dans le fleuve Amazone près de Leticia (Colombie). Alobophora diffère de Caballerotrema Prudhoe, 1960 par l'absence de projections du collier céphalique et par la présence d'épines angulaires groupées et d'un collier céphalique étroit (4 à 5 fois plus large que le pharynx), tandis que Caballerotrema présente des projections du collier céphalique, n'a pas d'épines angulaires groupées et a un collier céphalique large (7 à 8 fois plus large que le pharynx). Nous réaffectons Caballerotrema annulatum (Diesing, 1850) Ostrowski de Núñez & Sattmann, 2002 au nouveau genre, sous le nom d'Alobophora annulata (Diesing, 1850) Cajiao-Mora et Bullard n. comb., et fournissons une description supplémentaire de Caballerotrema brasiliense Prudhoe, 1960 basée sur des spécimens que nous avons collectés sur des arapaïmas. Nous avons également examiné l'holotype et un paratype de Caballerotrema piscicola (Stunkard, 1960) Kostadinova & Gibson, 2001 et avons conclu que C. piscicola est un synonyme subjectif junior de C. brasiliense. Notre phylogénie 28S a trouvé A. sandrae groupe-frère d'A. annulata, avec ce clade frère d'un clade comprenant C. brasiliense et une espèce non nommée de Caballerotrema. Les Caballerotrematidae ont été trouvés comme groupe-frère des Echinostomatidae. Nous fournissons également une clé dichotomique des Caballerotrematidae basée sur les projections du collier de la tête, la disposition des épines d'angle, la largeur proportionnelle du pharynx et du collier de la tête, la forme et la disposition des testicules, la forme et la distribution des épines de la surface du corps, la distribution du vitellarium et l'abondance des cellules prostatiques.