Intra-individual internal transcribed spacer 1 (ITS1) and ITS2 ribosomal sequence variation linked with multiple rDNA loci: A case of triploid Atractolytocestus huronensis, the monozoic cestode of common carp

Complete sequences of the ribosomal internal transcribed spacers (ITS1 and ITS2) and karyological characters of the monozoic (unsegmented) tapeworm Atractolytocestus huronensis Anthony, 1958 (Cestoda: Caryophyllidea) from Slovakia were analysed, revealing considerable intra-genomic variability and triploidy in all analysed specimens. Analysis of 20 sequences of each ITS1 and ITS2 spacer yielded eight and 10 different sequence types, respectively. In individual tapeworms, two to four ITS1 and three to four ITS2 sequence types were found. Divergent intra-genomic ITS copies were mostly induced by nucleotide substitutions and different numbers of short repetitive motifs within the sequence. In addition, triploidy was found to be a common feature of A. huronensis. The karyotype of Slovakian A. huronensis possesses three sets of chromosomes (3n = 24, n = 4m + 3st + 1 minute chromosome), similar to the previously described triploidy in conspecific tapeworms from North America. Fluorescent in situ hybridisation (FISH) with a ssrDNA probe revealed two distinct rDNA clusters for each homologue of the triplet number 2. To date, A. huronensis is the only cestode species in which intra-individual ITS sequence variants were found in parallel with its triploid nature and multiple rDNA loci. Some of these molecular and genetic features were observed in several other species of basal or nearly basal tapeworms of the orders Caryophyllidea and Diphyllobothriidea, which indicates that the phenomena may be characteristic for evolutionarily lower tapeworms and deserve more attention in future studies.     

Morphological differences and molecular phylogenetic relationship of two tapeworm species,Moniezia expansa and Moniezia benedeni,collected from domestic ruminants in northern Vietnam

Moniezia expansa and M. benedeni are two common tapeworm species of domestic ruminants over the world. However, their morphological and molecular data are available for limited specimens from a few countries. In the present study, we compared morphological characteristics of these two species collected from goats and cattle in northern Vietnam and analyzed their phylogenetic relationship based on the 5.8S and second internal transcribed spacer (ITS2) of nuclear ribosomal DNA and the mitochondrial cytochrome c oxidase subunit I gene (cox1). The two species are clearly distinguishable from one another not only in the morphological appearance of the interproglottidal glands but also in the gross appearance of mature and gravid proglottids. Molecular analyses revealed that the 5.8S-ITS2 sequences of Vietnamese M. expansa were highly similar (99.7%) to the sequences from Japan and India, and made a common clade, which was clearly distinct from M. benedeni of Vietnam. For cox1 sequences, Vietnamese M. expansa showed a high similarity to and were grouped with the sequences from Ethiopia and some sequences from Senegal and China to make a common clade, which was separated from the remaining clades of Senegal and China. The cox1 sequences of M. benedeni from China, Vietnam, and Senegal were far distant (10.0–15.9%) from each other. The results of this study suggest that more sequence data of Moniezia species with details of morphological features from various geographical locations should be obtained to clarify the taxonomic status of Moniezia species.     

Characterization of Phytophthora hybrids from ITS clade 6 associated with riparian ecosystems in South Africa and Australia

Surveys of Australian and South African rivers revealed numerous Phytophthora isolates residing in clade 6 of the genus, with internal transcribed spacer (ITS) gene regions that were either highly polymorphic or unsequenceable. These isolates were suspected to be hybrids. Three nuclear loci, the ITS region, two single copy loci (antisilencing factor (ASF) and G protein alpha subunit (GPA)), and one mitochondrial locus (cytochrome oxidase c subunit I (coxI)) were amplified and sequenced to test this hypothesis. Abundant recombination within the ITS region was observed. This, combined with phylogenetic comparisons of the other three loci, confirmed the presence of four different hybrid types involving the three described parent species Phytophthora amnicola, Phytophthora thermophila, and Phytophthora taxon PgChlamydo. In all cases, only a single coxI allele was detected, suggesting that hybrids arose from sexual recombination. All the hybrid isolates were sterile in culture and all their physiological traits tended to resemble those of the maternal parents. Nothing is known regarding their host range or pathogenicity. Nonetheless, as several isolates from Western Australia were obtained from the rhizosphere soil of dying plants, they should be regarded as potential threats to plant health. The frequent occurrence of the hybrids and their parent species in Australia strongly suggests an Australian origin and a subsequent introduction into South Africa.     

Re-evaluation of Japanese Phytophthora isolates based on molecular phylogenetic analyses

Over the past 40 years in Japan, Phytophthora isolates have been collected from various diseased host tissues and infested soils and identified using morphological characters. In order to develop a molecular method for the characterization of Japanese Phytophthora species, we obtained nuclear ribosomal ITS and LSU and mitochondrial coxI DNA sequences from 151 isolates representing 21 known species and 10 unidentified isolates. These were compared with similar sequences from representative isolates of known species. Of these, 124 isolates were found to have been correctly identified. Among the remaining 37 isolates, 19 showed high homology with other described species. The remaining 18 isolates showed only low levels of homology with any known species, and generated monophyletic sub-clades in a phylogenetic tree based on the ITS and nLSU regions and the coxI gene. Therefore, these isolates are candidates for new species, falling into six groups. Together, the Japanese isolates were found to represent phylogenetically diverse groups of species. In a sequence variation analysis, the ITS regions and the coxI genes were found to be more variable than the nLSU sequences, suggesting that they will be more useful for Phytophthora identification.     

First report on cystacanths of <Emphasis Type="Italic">Sphaerirostris lanceoides</Emphasis> (Petrochenko, 1949) (Acanthocephala: Centrorhynchidae) from the Asiatic toad <Emphasis Type="Italic">Bufo gargarizans</Emphasis> Cantor (Amphibia: Anura) in China

Everted cystacanths of Sphaerirostris lanceoides (Petrochenko, 1949) Golvan 1956 are reported from the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura) for the first time. The prevalence was 1.96% and the intensity ranged between 1.0–3.0 acanthocephalans. SEM observations revealed the morphology of the gonopore and the presence of a flat, bare region on the apical part of the proboscis. Moreover, S. lanceoides was characterised using molecular approaches by sequencing the ribosomal ITS1-5.8S-ITS2 region and the mitochondrial cox1 gene. The resulting ITS sequences were identical and the cox1 sequences showed a divergence of 0–0.75%. Sphaerirostris lanceoides is the first species of the genus for which the ITS1-5.8S-ITS2 and cox1 loci have been sequenced to aid species identification.     

Morphologic and Genetic Identification of Diphyllobothrium nihonkaiense in Korea

Diphyllobothrium nihonkaiense was first described by Yamane in 1986 but the taxonomical features have been obscure due to lack of critical morphologic criteria in its larval and adult stages. In Korea, this tapeworm had long been known as Diphyllobothrium latum. In this study, we observed 62 specimens collected from Korean residents and analyzed them by morphological features and nucleotide sequences of mitochondrial cox1 gene as well as the ITS1 region. Adult tapeworms were examined after carmine or trichrome stain. Longitudinal sections of the gravid proglottids showed an obtuse angle of about 150 degree between the cirrus sac and seminal vesicle. This angle is known as a major differential point compared with that of D. latum. Nucleotide sequence differences between D. latum and the specimens from Koreans represented 17.3% in mitochondrial DNA cox1 gene. Sequence divergence of ITS1 among 4 Korean isolates was 0.3% and similarity was 99.7% with D. nihonkaiense and D. klebanovskii. All of the Korean specimens analyzed in this study were identified as being D. nihonkaiense (n = 62). We propose its Korean name as "Dong-hae-gin-chon-chung" which means ''long tapeworm of the East Sea'' for this newly analyzed diphyllobothriid tapeworm in Korea.     

Cryptic diversity in hymenolepidid tapeworms infecting humans

An adult hymenolepidid tapeworm was recovered from a 52-year-old Tibetan woman during a routine epidemiological survey for human taeniasis/cysticercosis in Sichuan, China. Phylogenetic analyses based on sequences of nuclear 28S ribosomal DNA and mitochondrial cytochrome c oxidase subunit 1 showed that the human isolate is distinct from Hymenolepis diminuta and Hymenolepis nana, the common parasites causing human hymenolepiasis. Proglottids of the human isolate were unfortunately unsuitable for morphological identification. However, the resultant phylogeny demonstrated the human isolate to be a sister species to Hymenolepis hibernia from Apodemus mice in Eurasia. The present data clearly indicate that hymenolepidid tapeworms causing human infections are not restricted to only H. diminuta and H. nana.     

Occurrence and Molecular Identification of Microcotyle sebastis Isolated from Fish Farms of the Korean Rockfish,Sebastes schlegelii

Microcotyle sebastis is a gill monogenean ectoparasite that causes serious problems in the mariculture of the Korean rockfish, Sebastes schlegelii. In this study, we isolated the parasite from fish farms along the coasts of Tongyeong, South Korea in 2016, and characterized its infection, morphology and molecular phylogeny. The prevalence of M. sebastis infection during the study period ranged from 46.7% to 96.7%, and the mean intensity was 2.3 to 31.4 ind./fish, indicating that the fish was constantly exposed to parasitic infections throughout the year. Morphological observations under light and scanning electron microscopes of the M. sebastis isolates in this study showed the typical characteristics of the anterior prohaptor and posterior opisthaptor of monogenean parasites. In phylogenetic trees reconstructed using the nuclear 28S ribosomal RNA gene and the mitochondrial cytochrome c oxidase I gene (cox1), they consistently clustered together with their congeneric species, and showed the closest phylogenetic relationships to M. caudata and M. kasago in the cox1 tree.     

Molecular data reveal a new species of Seuratascaris Sprent, 1985 (Nematoda: Ascaridoidea) from Quasipaa exilispinosa (Liu & Hu) (Amphibia: Anura)

The genus Seuratascaris Sprent, 1985 is a group of obligate nematode parasites of amphibians. In the present study, a new species of Seuratascaris, S. physalis sp. n. was described using light and scanning electron microscopy based on specimens collected from Quasipaa exilispinosa (Liu & Hu) (Amphibia: Anura) in China. The new species differs from S. numidica (Seurat, 1917) by the cuticle of the cervical region distinctly inflated to form a cephalic vesicle-like structure and the absence of single medio-ventral precloacal papilla. The molecular characterization of the nuclear large ribosomal DNA (28S) and internal transcribed spacer (ITS) and the mitochondrial cytochrome c oxidase subunit 1 (cox1), cytochrome c oxidase subunit 2 (cox2) and 12S small subunit ribosomal RNA gene of S. physalis sp. n., together with the 28S, cox2 and 12S of S. numidica are provided for the first time. Molecular analysis revealed the presence of high level of interspecific genetic variation between the two species in the ITS (5.50%), cox1 (13.3%), cox2 (10.6%) and 12S regions (10.5%), which strongly supported that S. physalis sp. n. represented a different species from S. numidica. Angusticaecum ranae Wang, Zhao & Chen, 1978 reported from the frog Quasipaa spinosa (David) (Anura: Dicroglossidae) in China was transferred into the genus Seuratascaris as S. ranae (Wang, Zhao & Chen, 1978) comb. n. based on the morphology of lips and the presence of very short and robust spicules without alae and small numbers of precloacal papillae. The present study provided useful genetic data for molecular identification of species of Seuratascaris and provides the foundation for being able to determine if S. numidica represents a species complex of some sibling species or a single species.     

Checklist of tapeworms (Platyhelminthes,Cestoda) of vertebrates in Finland

A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonus nylandicus Schneider, 1902 (a junior synonym of Diplocotyle olrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeides fennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History.     

Karyotype,chromosomal characteristics of multiple rDNA clusters and intragenomic variability of ribosomal ITS2 in Caryophyllaeides fennica (Cestoda)

Karyotype and chromosomal characteristics, i.e. number and location of ribosomal DNA (rDNA) clusters, and sequence variation of the ribosomal internal transcribed spacer 2 (ITS2) were studied in a monozoic (unsegmented) tapeworm, Caryophyllaeides fennica (Caryophyllidea), using conventional and Ag-staining, fluorescent in situ hybridization (FISH) with 18S rDNA probe, and PCR amplification, cloning and sequencing of the complete ribosomal ITS2 spacer. The karyotype of this species was composed of ten pairs of metacentric (m) chromosomes (2n = 20). All chromosomes except the pair No. 2 displayed DAPI-positive heterochromatin in centromeric regions. In addition, two distinct interstitial DAPI-positive bands were identified on chromosome pair No. 7. FISH with 18S rDNA probe revealed four clusters of major ribosomal genes situated in the pericentromeric region of the short arms in two pairs of metacentric chromosomes Nos. 8 and 9. Hybridization signals were stronger in the pair No. 8, indicating a higher amount of rDNA repeats at this nucleolar organizer region (NOR). Analysis of 15 ITS2 rDNA sequences (five recombinant clones from each of three individuals) showed 13 structurally different ribotypes, distinguished by 26 nucleotide substitutions and variable numbers and combinations of short repetitive motifs that allowed sorting the sequences into four ITS2 variants. These results contribute to recently published evidence for the intraindividual ribosomal ITS sequence variability in basal tapeworms with multiple rDNA loci and imply that both phenomena may be mutually linked.     

Morphological and molecular evidence for a new species of the genus Dichelyne Jägerskiöld, 1902 (Ascaridida: Cucullanidae) from marine perciform fishes in the South China Sea

A new cucullanid nematode, Dichelyne (Dichelyne) breviculus n. sp., collected from the intestine of the goatee croaker Dendrophysa russelii (Cuvier) (Perciformes: Sciaenidae), the burrowing goby Trypauchen vagina (Bloch & Schneider) and the tropical sand goby Acentrogobius caninus (Valenciennes) (Perciformes: Gobiidae) in the South China Sea, is described using both light and scanning electron microscopy. The new species differs from its congeners in the size of body (2.16–2.96 mm in male), the position of the excretory pore and deirids, the length of the spicules (0.90–1.32 mm, representing 32.4–51.9% of body length), the arrangement of the caudal papillae and the morphology of the tail. In addition, in order to primarily assess the validity of the new species genetically, the specimens of D. breviculus n. sp. collected from the three different hosts were also characterised using molecular methods by sequencing and analysing ribosomal [small ribosomal subunit (18S rDNA) and internal transcribed spacer (ITS)] and mitochondrial [cytochrome c oxidase subunit 1 (cox1)] target regions. The molecular analyses support the validity of the new species based on the morphological observations.     

Genetics of the Pig Tapeworm in Madagascar Reveal a History of Human Dispersal and Colonization

An intricate history of human dispersal and geographic colonization has strongly affected the distribution of human pathogens. The pig tapeworm Taenia solium occurs throughout the world as the causative agent of cysticercosis, one of the most serious neglected tropical diseases. Discrete genetic lineages of T. solium in Asia and Africa/Latin America are geographically disjunct; only in Madagascar are they sympatric. Linguistic, archaeological and genetic evidence has indicated that the people in Madagascar have mixed ancestry from Island Southeast Asia and East Africa. Hence, anthropogenic introduction of the tapeworm from Southeast Asia and Africa had been postulated. This study shows that the major mitochondrial haplotype of T. solium in Madagascar is closely related to those from the Indian Subcontinent. Parasitological evidence presented here, and human genetics previously reported, support the hypothesis of an Indian influence on Malagasy culture coinciding with periods of early human migration onto the island. We also found evidence of nuclear-mitochondrial discordance in single tapeworms, indicating unexpected cross-fertilization between the two lineages of T. solium. Analyses of genetic and geographic populations of T. solium in Madagascar will shed light on apparently rapid evolution of this organism driven by recent (<2,000 yr) human migrations, following tens of thousands of years of geographic isolation.     

The cestode Atractolytocestus huronensis (Caryophyllidea) continues to spread in Europe: new data on the helminth parasite of the common carp

The caryophyllidean tapeworm Atractolytocestus huronensis Anthony, 1958, originally described from the common carp Cyprinus carpio carpio L. from North America, has recently been introduced into Europe (UK, Hungary). In the present study, the dispersion of the tapeworm in other countries of Central Europe (Slovakia and the Czech Republic) is described, including its first observation in the common carp of the Tisa River, southeastern Slovakia. Because of the transboundary location of the river, there are possible consequences of the rapid distribution of the parasite to other regions throughout the Danube River basin. The parasite has also been found in cultured carp from fishponds in South Bohemia, from where the carp are imported to many European countries. Rapid dissemination of this cestode in Europe indicates its ability to colonise new regions, and represents another example of man-made introduction of potential pathogens of carp and other farmed fish. The morphology of the A. huronensis specimens found is compared with that of specimens from Hungary and North America as well as that of Atractolytocestus sagittatus (Kulakovskaya and Akhmerov, 1965) from the same fish host in eastern Asia.     

Morphology and molecules reveal the alien <Emphasis Type="Italic">Posthodiplostomum centrarchi</Emphasis> Hoffman, 1958 as the third species of <Emphasis Type="Italic">Posthodiplostomum</Emphasis> Dubois, 1936 (Digenea: Diplostomidae) in Europe

Metacercariae of two species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) were subjected to morphological and molecular studies: P. brevicaudatum (von Nordmann, 1832) from Gasterosteus aculeatus (L.) (Gasterosteiformes: Gasterosteidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Perca fluviatilis L. (Perciformes: Percidae), Czech Republic (morphology, cox1, ITS1-5.8S-ITS2 and 28S); and P. centrarchi Hoffman, 1958 from Lepomis gibbosus (L.) (Perciformes: Centrarchidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Slovakia (cox1 and ITS1-5.8S-ITS2). In addition, cercariae of P. cuticola (von Nordmann, 1832) from Planorbis planorbis (L.) (Mollusca: Planorbidae), Lithuania (morphology and cox1) and metacercariae of Ornithodiplostomum scardinii (Schulman in Dubinin, 1952) from Scardinius erythrophthalmus (L.) (Cypriniformes: Cyprinidae), Czech Republic, were examined (morphology, cox1, ITS1-5.8S-ITS2 and 28S). These represent the first molecular data for species of Posthodiplostomum and Ornithodiplostomum Dubois, 1936 from the Palaearctic. Phylogenetic analyses based on cox1 and ITS1-5.8S-ITS2, using O. scardinii as the outgroup and including the three newly-sequenced Posthodiplostomum spp. from Europe and eight published unidentified (presumably species-level) lineages of Posthodiplostomum from Canada confirmed the distinct status of the three European species (contrary to the generally accepted opinion that only P. brevicaudatum and P. cuticola occur in the Palaearctic). The subspecies Posthodiplostomum minimum centrarchi Hoffmann, 1958, originally described from North America, is elevated to the species level as Posthodiplostomum centrarchi Hoffman, 1958. The undescribed “Posthodiplostomum sp. 3” of Locke et al. (2010) from centrarchid fishes in Canada has identical sequences with the European isolates of P. centrarchi and is recognised as belonging to the same species. The latter parasite, occurring in the alien pumpkinseed sunfish Lepomis gibbosus in Europe, is also supposed to be alien for this continent. It is speculated that it colonised Europe long ago and is currently widespread (recorded in Bulgaria, Slovakia and Spain); based on the cox1 sequence of an adult digenean isolate from the Ebro Delta, Spain, only the grey heron (Ardea cinerea L.) (Ciconiiformes: Ardeidae) is known to be its definitive host in Europe.     

Morphological and molecular differentiation of Parastrigea (Trematoda: Strigeidae) from Mexico,with the description of a new species

Parastrigea plataleae n. sp. (Digenea: Strigeidae) is described from the intestine of the roseate spoonbill Platalea ajaja (Threskiornithidae) from four localities on the Pacific coast of Mexico. The new species is mainly distinguished from the other 18 described species of Parastrigea based on the ratio of its hindbody length to forebody length. A principal component analysis (PCA) of 16 morphometric traits for 15 specimens of P. plataleae n. sp., five of Parastrigea cincta and 11 of Parastrigea diovadena previously recorded in Mexico, clearly shows three clusters, which correspond to the three species. DNA sequences of the internal transcribed spacers (ITSs) of ribosomal DNA and the mitochondrial gene cytochrome c oxidase subunit I (cox 1) were used to corroborate this morphological distinction. The genetic divergence estimated among P. plataleae n. sp., P. cincta and P. diovadena ranged from 0.5 to 1.48% for ITSs and from 9.31 to 11.47% for cox 1. Maximum parsimony (MP) and maximum likelihood (ML) analyses were performed on the combined datasets (ITSs + cox 1) and on each dataset alone. All of the phylogenetic analyses indicated that the specimens from the roseate spoonbill represent a clade with strong bootstrap support. The morphological evidence and the genetic divergence in combination with the reciprocal monophyly in all of the phylogenetic trees support the hypothesis that the digeneans found in the intestines of roseate spoonbills represent a new species.     

Geography and host specificity: two forces behind the genetic structure of the freshwater fish parasite Ligula intestinalis (Cestoda: Diphyllobothriidae)

Parasite species with global distributions and complex life cycles offer a rare opportunity to study alternative mechanisms of speciation and evolution in a single model. Here, genealogy and genetic structure, with respect to geography and fish host preference, have been analyzed for Ligula intestinalis, a tapeworm affecting freshwater fish. The data analyzed consisted of 109 tapeworms sampled from 13 fish host species in 18 different localities on a macrogeographic scale. Two mitochondrial genes, cytochrome oxidase subunit I and cytochrome B, and the nuclear sequence of intergenic transcribed spacer 2 (ITS2) were used for the genetic reconstruction. Different evolutionary patterns were found at the local and at the global geographic scales. On a local scale, the flat genetic structure was mainly attributed to contiguous range expansion. Migrating birds are the most likely cause of the homogenisation of the whole population, preventing the creation of significant genetic barriers. By contrast, on a global scale, genetically distant and well-separated clusters are present in different geographic areas. Reproductive isolation was found even between clades living in sympatry and infecting the same definitive host, suggesting the existence of efficient biologically determined genetic barriers, and thus possibly separate species. Although the ITS2 sequences were found to display considerable intragenomic variability, their relationships were generally in good agreement with the topology derived from mitochondrial genes.     

A multigene phylogeny of theGibberella fujikuroi species complex: Detection of additional phylogenetically distinct species

Phylogenetic relationships within theGibberella fujikuroi species complex were extended to newly discovered strains using nucleotide characters obtained by sequencing polymerase chain reaction (PCR) amplified DNA from 4 loci used in a previous study [nuclear large subunit 28S rDNA, nuclear ribosomal internal transcribed spacer (ITS) region, mitochondriaal small subunit (mtSSU) ribosomal DNA, and β-tubulin] together with two newly sampled protein-encoding nuclear genes, translation elongation factor EF-1α and calmodulin. Sequences from the ribosomal ITS region were analyzed separately and found to contain of two highly divergent, nonorthologous ITS2 types. Phylogenetic analysis of the individual and combined datasets identified 10 new phylogenetically distinct species distributed among the following three areas: 2 within Asia and 4 within both Africa and South America. Hypotheses of the monophyly ofFusarium subglutinans and its two formae speciales, f. sp.pini and f. sp.ananas, were strongly rejected by a likelihood analysis. Maximum parsimony results further indicate that the protein-encoding nuclear genes provide considerably more phylogenetic signal that the ribosomal genes sequenced. Relative apparent synapomorphy analysis was used to detect long-branch attraction taxa and to obtain a statistical measure of phylogenetic signal in the individual and combined datasets.     

The phylogeny of the genus Indoplanorbis (Gastropoda,Planorbidae) from Africa and the French West Indies

Indoplanorbis exustus is a freshwater snail known as the intermediate host of various trematode parasites, including different species of the genus Schistosoma. Although its genetic diversity is well described in Asia, the phylogenetic diversity of strains from Africa and Guadeloupe (French West Indies) and their relationship to Asian and South‐East Asian strains remain unknown. To tackle this issue, we sampled individuals from Africa and Guadeloupe, and we computed phylogenetic reconstructions using five molecular markers: partial sequences of two mitochondrial genes, cox1 and 16S, and three nuclear markers, ITS1, ITS2 (Internal Transcribed Spacer 1 and 2) and 5.8S. Our results suggest that strains in Africa and Guadeloupe come from Asia and that they all belong to a single clade that is widespread around the globe.     

Molecular evidence confirms the parasite Congracilaria babae (Gracilariaceae,Rhodophyta) from Malaysia

A phylogenetic study of two parasites found on the common host species Gracilaria salicornia from Japan and Malaysia based on nuclear, plastid, and mitochondrial molecular markers was conducted. The Japanese and Malaysian parasites were placed in the same cluster in the nuclear phylogenies inferred from the LSU rRNA gene and ITS region, supporting the monophyly of these parasites despite the slight anatomical variations observed. In addition to the molecular analyses, shared morphological and reproductive features including the lack of rhizoids, similar coloration to hosts, and the presence of deep spermatangial conceptacles supported the inclusion of both the Japanese and Malaysian parasites in Congracilaria babae. Phylogenetic analyses based on ITS sequences indicated that C. babae most likely evolved directly from its current host species, G. salicornia. C. babae was shown to be a member of Gracilaria sensu stricto along with its host. C. babae growing on G. salicornia is characterized by having plastid rbcL and mitochondrial cox1 gene sequences identical to those of its host, whereas the nuclear LSU rRNA gene and ITS region sequences are different from those of its host.