Discovery of a Cryptic Species, Erysiphe Salicina Sp. Nov., and Reconstruction of The Phylogeny of Powdery Mildews On Populus and Salix Spp.

Recently performed phylogenetic-taxonomic analyses of species belonging to Erysiphe sect. Uncinula on willows (Salix spp.) demonstrated a much higher diversity than previously assumed. Phylogenetic analyses and morphological examinations of Chinese Erysiphe collections on Salix abscondita (= S. raddeana), S. sinica and S. taraikensis, all belonging to Salix subgen. Vetrix sect. Vetrix, revealed an additional cryptic species in sister position to the E. salicis clade, which is described as Erysiphe salicina. The new species clearly distinguished from all allied species in morphological and genetical results. The phylogeny of the new species and closely related species on Populus and Salix spp. (Salicaceae) was reconstructed and discussed using a combined alignment of the internal transcribed spacer (ITS) regions and 28S rDNA sequences. The present phylogenetic analyses suggest that the recently described E. salicicola (on Salix gracilistyla in South Korea) has to be reduced to synonymy with E. salicis var. salicis-gracilistylae (º Uncinula salicis-gracilistylae).

Gammarinema scyllae sp. n. and Monhystrium mangrovi sp. n. (Nematoda: Monhysteridae) from land crabs from New Caledonia

Two new species of nematodes associated with crabs are described from New Caledonia. Gammarinema scyllaesp. n. from the gill chambers of Scylla serrata (Forsskål) is characterised by 3–4 mm long body, small outer labial and cephalic sensilla, distinct ocelli, short straight spicules and sub-cylindrical tail. Monhystrium mangrovisp. n. from the gill chambers and body cavity of mangrove crab Neosarmatium sp. is characterised by 1–1.4 mm long body; outer labial sensilla longer than cephalic sensilla, amphid located at level with posterior stoma chamber, denticles in posterior stoma chamber and five pairs of genital papilla on tail. Phylogenetic relationships of two new species and other nematodes from the family Monhysteridae are analysed based on 18S and partial 28S rDNA sequences.

Morphological, Morphometrical and Molecular Characterization of Oscheius siddiqii Tabassum and Shahina, 2010 (Rhabditida, Rhabditidae) from India with Its Taxonomic Consequences for the Subgenus Oscheius Andrássy, 1976

An insect parasitic nematode belonging to the genus Oscheius was recovered from the agricultural soils from the Hapur district in western Uttar Pradesh, India. Morphological studies on this species exhibited its high resemblance with two Pakistani species: Oscheius siddiqii and O. niazii. No molecular data are available for these taxa but, morphologically, both species do not differ significantly from our strains and each other. Hence, these nematodes can be considered conspecific, and the correct name for this taxon is O. siddiqii, the first described species. The phylogenetic analyses of the ITS-, 18S-, and the 28S rDNA sequences showed that O. siddiqii is a sister taxon to the group formed by Oscheius microvilli, O. myriophilus, O. safricanus, and several unidentified Oscheius species. Additionally, our analyses show that based on molecular and morphological data, the species Oscheius rugaoensis and O. microvilli cannot be distinguished from O. chongmingensis and O. myriophilus, respectively, and are thus considered junior synonyms of these taxa. Furthermore, the available data are not sufficient to evaluate the status of Oscheius basothovii and O. safricanus, which are, in consequence, considered species inquirendae. These findings highlight the necessity of the proper morphological and molecular characterisation of the described Oscheius species.

Molecular evolutionary relationships of Vietnamese and global pulmonary Paragonimus species in the family paragonimidae and suborder xiphidiata (Platyhelminthes: Trematoda)

Paragonimiasis, caused by Paragonimus species belonging to the family Paragonimidae of the suborder Xiphidiata (Platyhelminthes: Trematoda), often occurs in poor, upland, ethnic minorities, in Vietnam and the world. Asian Paragonimus species are distributed from Japan, South Korea, along with North and Southeast China, North-West and Central Vietnam, the Philippines, Thailand, Bangladesh, India, and Sri Lanka. There are various genetic variants, strains, and genotypes forming different complexes and evolutionary lineages. The 18S, 28S rDNA sequences and the intergenic transcribed spacer regions (ITS-1, ITS-2) of nuclear ribosomal transcription units are commonly used as molecular markers in genetic studies and phylogenetic analyses. We obtained a portion of 28S rDNA (domains D1–D3) of Paragonimus spp. including P. heterotremus (from Vietnam), P. ohirai (Japan), P. iloktsuenensis (Japan), and P. westermani (India and Vietnam) and conducted phylogenetic analysis for molecular evolutionary studies. The results showed that the family Paragonimidae formed the biggest cluster in a phylogenetic tree, which comprises of 46 sequences of 11 species belonging to 11 subgroups, among which the P. westermani complex of strains originating from China, Korea, Japan, India, Philippines, Malaysia, and Vietnam is present. P. westermani complex is arranged in a position of "sister" (sister group) with the subgroup P. siamensis. The P. heterotremus and P. ohirai complexes, and the P. miyazakii, P. harinasutai, P. mexicanus, P. kellicotti, and P. macrorchis complexes are clustered in a common population. P. westermani of Vietnam is in close proximity to the East Asian strains, as of which has been previously reported. P. ohirai and P. iloktsuenensis are considered “sibling” species, sharing the same clade. Phylogenetic analysis using the 28S rDNA sequences directly presented species position and their molecular evolutionary relationships in the families Paragonimidae, Troglotrematidae, Nanophyetidae, and Collyriclidae. Evolutionary analysis has also clarified a number of complex delineation problems and made a clear nomenclature for Paragonimus sp. of Vietnam, in particular, which has scientific grounds merited to recognize as that it is really the P. westermani species.

Phylogenetic analyses of ribosomal transcription units from Haplorchis taichui and H. pumilio species of Heterophyidae (Platyhelminthes: Opisthorchiata)

Heterophyidiasis caused by minute intestinal flukes becomes of public concern in many countries worldwide. Haplorchis taichui and H. pumilio, belonging to the family Heterophyidae (Platyhelminthes: Trematoda) are two of many infecting humans and commonly found in Vietnam. Sequence study of these two small intestinal flukes is still very limited, hence we need more prospective markers for taxonomic identification and classification. This study provides complete coding sequence of the ribosomal transcription units (rTU) from H. taichui and H. pumilio (Vietnamese samples) and demonstrates the use of complete 28S rDNA sequences for phylogenetic analysis.The complete coding sequence of the rTU (from 5' 18S to 3' 28S), consisting of complete 18S, ITS-1, 5.8S, ITS2 and complete 28S rRNA genes and spacers, from H. taichui (7,268 bp) and H. pumilio (7,416 bp) from human hosts in Vietnam, were determined and annotated. The 18S and 5.8S genes of both species were of the same length (1,992 bp/18S, 160 bp/5.8S), but 28S genes differed (3,875 bp/H. taichui and 3,870 bp/H. pumilio). ITS-1 in H. taichui (797 bp) and ITS-2 in H. pumilio (280 bp) do not contain tandem repeat units (TRUs), while ITS-1 in H. pumilio (1,106 bp) contains 3 TRUs of 136 bp/each and 2 TRUs of 116 bp/each and ITS-2 in H. taichui (444 bp) contain 3 TRUs (83–85 bp/each). A phylogenetic tree inferred from the alignment of complete 28S rDNA sequences of 32 trematode strains/species, including 2 Vietnamese Haplorchis spp. and 24 species of 8 families in the suborders Xiphidiata (families Nanophyetidae, Paragonimidae, Collyriclidae), Opisthorchiata (Heterophyidae, Opisthorchiidae), and Echinostomata (Echinostomatidae, Fasciolidae). and Schistosoma japonicum of the family Schistosomatidae is used as an outgroup. The topology of the phylogenetic tree clearly confirmed the status of the Vietnamese H. taichui and H. pumilio species. These species gathered in a group (in the family Heterophyidae) clearly identified in the position of "sister” group to those in the family Opisthorchiidae (suborder Opisthorchiata, superfamily Opisthorchioidea).

Redescription and New Host Record of Heteraxinoides atlanticus (Monogenea: Heteraxinidae) from the Gills of Nemipterus japonicus (Bloch) and Its Systematics

Background: Heteraxinoides atlanticus Gayevskaya et Kovaleva (1979) is described from the locality of Arabian Sea, India. This monogenean species is first time reported from India, infesting the gills of Nemipterus japonicus (Bloch). The present study redescribes H. atlanticus and its phylogenetic status using morphometric and molecular tools. Methods: A total of 35 parasites were collected from the 234 specimens of Nemipterus japonicus at Mumbai, India. The temporary and permanent mounts were prepared for the morphometric analyses of H. atlanticus. For PCR, the genomic DNA was isolated from the parasites using primers for 18S rDNA, 28S rDNA and mtCOI gene. The obtained DNA sequences were subjected to different bioinformatics softwares (BLASTn, Clustal Omega and MEGA) for phlyogenetic analyses.Result: Phylogenetic analyses with the help of partial 18S and 28S rDNA sequences of H. atlanticus and other available sequences of heteraxinids provided the better understanding of relationship in the family Heteraxinidae. Another species, H. karachiensis Hadi and Bilqees (2014) showed similar morphological features such as number of clamps and structure of genital atrium to H. atlanticus except few minor differences, so it must be considered as synonym of H. atlanticus and placed into Heteraxinidae instead of Axinidae.

Taxonomy and phylogeny of Koinocystididae (Platyhelminthes, Kalyptorhynchia), with the description of three new genera and twelve new species

The taxon Koinocystididae is the third most species-rich family within Eukalyptorhynchia. However, its diversity and phylogeny have been largely neglected in former studies. We introduce three new genera and twelve new species of Koinocystididae including Simplexcystis asymmetrica gen. n. sp. n., Galapagetula cubensis sp. n., eight species of Reinhardorhynchus gen. n. and two species of Itaipusa. This raises the total number of species within Koinocystididae from 51 to 63. We also report on new distribution records for six known species: I. divae (Cuba, Panama and New Caledonia), I. karlingi (Sardinia and Lanzarote), Reinhardorhynchus riegeri comb. n. (Cuba), R. ruffinjonesi comb. n. (Cuba and Panama), Utelga heinckei (Cuba and Lanzarote), and U. pseudoheinckei (Sardinia). Simplexcystis asymmetrica gen. n. sp. n. is characterised by a male duct running eccentrically through the copulatory bulb, lack of any hard structures in the male system, lack of a bursa, and the fact that the epithelia of the female, the male, and part of the common atrium are covered by a brush border. Galapagetula cubensis sp. n. has a caudal gonopore, a divisa-type copulatory bulb with an unarmed penis papilla, and a female duct without a sphincter. The new species of Itaipusa and Reinhardorhynchus gen. n. differ from their congeners in the detailed structure of the copulatory bulb and especially the hard structures associated with it. In a molecular phylogenetic analysis based on all available 18S and 28S rDNA sequences of koinocystidids, we found support for the monophyly of the family and the genus Utelga Marcus, 1949. The genus Itaipusa is not monophyletic in that I. sinensis forms a clade with Rhinolasius dillonicus, while other species of Itaipusa that have a copulatory bulb armed with hooks form a clade together with Sekerana stolzi. As the type species of Itaipusa (I. divae) is in neither of these clades, we erected a new genus for I. sinensis (Koinogladius gen. n.) and one for species of Itaipusa having a hook-bearing copulatory bulb (Reinhardorhynchus gen. n.), respectively. Whether the remaining species of Itaipusa form a monophylum remains uncertain.

Redescription and synonymization of Oscheius citri Tabassum, Shahina, Nasira and Erum, 2016 (Rhabditida, Rhabditidae) from India and its taxonomical consequences

A population of a nematode species belonging to the genus Oscheius was isolated in western Uttar Pradesh, India. Morphological and morphometrical studies on this species showed its high similarity with six species described previously from Pakistan (Oscheius citri, O. cobbi, O. cynodonti, O. esculentus, O. punctatus and O. sacchari). The molecular analysis of the ITS1-5.8S-ITS2 rDNA sequences of the Indian population and the six species described from Pakistan showed that all the sequences are almost identical. Thus, based on morphological and molecular characteristics, all of the six above-mentioned Pakistani species and Indian strain do not differ from each other, hence can be considered synonyms. The correct name for this taxon is the first described species O. citri. Additionally, the phylogenetic analysis of the 18S rDNA and the 28S rDNA sequences showed that Oscheius citri is sister to the clade formed by O. chongmingensis and O. rugaoensis from China. The high similarity of morphological and morphometric characteristics of O. citri and other species, O. maqbooli, O. nadarajani, O. niazii, O. shamimi and O. siddiqii, suggest their conspecificity; however, lack of molecular data for these species does not allow this hypothesis to be tested.

Phasmarhabditis zhejiangensis sp. nov. (Nematoda: Rhabditidae), a new rhabditid nematode from Zhejiang, China

A new nematode species of the genus Phasmarhabditis was isolated from the body surface of a slug (Philomycus bilineatus Benson, PB). Morphological and molecular analyses confirmed this nematode as a new species. The nematode was named Phasmarhabditis zhejiangensis sp. nov. (Nematoda: Rhabditidae) and is dioecious. In males, the open bursa with genital papillae is characterized by the formula 1-1-1-2-1-3, and the spicule length is 58μm. In female, the vulva is located approximately in the middle of the body. The nematode belongs to papillosa group because of its tail shape pointed with filiform tip. The phasmids are rod-shaped. The posterior anus is slightly swollen. P. zhejiangensis was further characterized by internal transcribed spacer (ITS), 18S rDNA and 28S rDNA sequences. After the sequencing results were compared with sequences available from the National Center for Biotechnology Information (NCBI), the maximum similarities of ITS, 18S and 28S sequences were 89.81%, 96.22% and 95.28%, respectively. Phylogenetic analyses placed Phasmarhabditis zhejiangensis sp. nov. in the genus Phasmarhabditis.

Description of Calcaridorylaimus heynsi n. sp. (Nematoda: Dorylaimidae) from Potchefstroom, South Africa

Summary Calcaridorylaimus heynsi n. sp. is the second species of the genus to be described by both morphological and molecular techniques. Morphologically, it can be distinguished from all known species of Calcaridorylaimus by a combination of the following characters: presence of advulval ornamentations, short body (0.90-1.33 mm), slightly anteriorly positioned vulva (V = 47.6 (45.8-49.8)), short odontostyle in females and males (13.1 (11.5-14.5) μm and 13.5 (12.0-18.0) μm, respectively), number of supplements (2 + 9-11), short spicules when measured along the median line (40.4 (38-42) μm) and pore-like vulval opening. It is closest to C. sirgeli, especially in the presence of advulval ornamentations and the pore-like vulva. Phylogenetic analysis based on partial D2-D3 segment of 28S rDNA sequences showed that C. heynsi n. sp. is in a well-supported sister relation with Mesodorylaimus sp. in a clade with C. cignatus and Mesodorylaimus spp. In the Bayesian tree, using partial sequences 18S rDNA, M. japonicus was the closest taxon to the new species.