Search

Background: The genus Enchodelus is an intriguing free-living dorylaimid nematode taxon. Its representatives display a distinct distributional pattern as they are mainly spread in high altitudinal enclaves of the Northern Hemisphere, being often associated with mosses and cliff vegetation. Although their feeding habits have not been studied with experimental protocols, it is traditionally assumed that they are omnivorous. The genus Enchodelus has not been recently revised; descriptions of many 'old species' (that have been described long ago and have not been reported since their original discovery) are of poor quality, hardly discoverable and do not conform to the nowadays taxonomical standards. Thus, a comprehensive compilation and analysis of their literature data is indispensable to provide new insights into the taxonomy of the genus and to elucidate its evolutionary relationships. New information: This contribution provides a cyber catalogue of all Enchodelus species, 28 in total. It compiles available information from the key European Research Infrastructures, such as TreatmentBank, Swiss Institute of Bioinformatics Literature Services (SIBiLS), the Catalogue of Life (CoL), Global Biodiversity Information Facility (GBIF), European Nucleotide Archive (ENA) and Biodiversity Literature Repository (BLR). Data about their distribution (geographical records and habitats) are incorporated too and all brought together. It is completed with discussion and notes for some species, along with information on species distributions and microhabitats. Here, all available information on Enchodelus species is brought together. This will contribute to a more complete assessment of species diversity and distribution and support further biogeographical and ecological research. Besides, type material Enchodelus vestibulifer Altherr, 1952, deposited in the Museo Cantonale di Storia Naturale di Lugano (Switzerland), is re-examined and the species is considered as incertae sedis. Further, a new species of the genus found in Caucasus, Georgia is described after its morphological and molecular study; also morphological and molecular data for E. macrodorus (de Man, 1880) Thorne, 1939, the type species of the genus, collected from Spain are provided. [ABSTRACT FROM AUTHOR]

Abstract Background Nematodes of the genus Heterorhabditis are important biocontrol agents as they form a lethal combination with their symbiotic Photorhabdus bacteria against agricultural insect pests. This study describes a new species of Heterorhabditis. Methods Six Heterorhabditis nematode populations were recovered from agricultural soils in Jammu and Kashmir, India. An initial examination using mitochondrial and nuclear genes showed that they belong to a new species. To describe this new species, a variety of analyses were conducted, including reconstructing phylogenetic relationships based on multiple genes, characterizing the nematodes at the morphological and morphometric levels, performing self-crossing and cross-hybridization experiments, and isolating and characterizing their symbiotic bacteria. Results The newly discovered species, Heterorhabditis casmirica n. sp., shares 94% mitochondrial cytochrome C oxidase subunit I gene (COI) sequence identity with Heterorhabditis bacteriophora and Heterorhabditis ruandica, and 93% with Heterorhabditis zacatecana. Morphologically, it differs from H. bacteriophora in its infective juvenile phasmids (present vs. inconspicuous) and bacterial pouch visibility in the ventricular portion of the intestine (invisible vs. visible); genital papilla 1 (GP1) position (at manubrium level vs. more anterior), and in its b ratio (body length/neck length), c ratio (tail length/bulb width), and D% [(excretory pore/neck length) × 100]. Other morphological differences include anterior end to the nerve ring distance (77–100 vs. 121–130 μm), V% [(anterior end of vulva/body length) × 100] (46–57 vs. 41–47) in hermaphroditic females; rectum size (slightly longer than the anal body diameter vs. about three times longer), phasmids (smaller vs. inconspicuous), body length (0.13–2.0 vs. 0.32–0.39 mm), body diameter (73–150 vs. 160–220 μm), anterior end to the excretory pore distance (135–157 vs. 174–214 μm), and demanian ratios in amphimictic females. Morphological differences with H. ruandica and H. zacatecana were also observed. Furthermore, H. casmirica n. sp. did not mate or produce fertile progeny with other Heterorhabditis nematodes reported from India. It was also discovered that H. casmirica n. sp. is associated with 'Photorhabdus laumondii subsp. clarkei symbiotic bacteria. Conclusions The discovery of H. casmirica n. sp. provides novel insights into the diversity and evolution of Heterorhabditis nematodes and their symbiotic bacteria. This new species adds to the catalog of entomopathogenic nematodes in India. Graphical Abstract

Background: Nematodes of the genus Heterorhabditis are important biocontrol agents as they form a lethal combination with their symbiotic Photorhabdus bacteria against agricultural insect pests. This study describes a new species of Heterorhabditis. Methods: Six Heterorhabditis nematode populations were recovered from agricultural soils in Jammu and Kashmir, India. An initial examination using mitochondrial and nuclear genes showed that they belong to a new species. To describe this new species, a variety of analyses were conducted, including reconstructing phylogenetic relationships based on multiple genes, characterizing the nematodes at the morphological and morphometric levels, performing self-crossing and cross-hybridization experiments, and isolating and characterizing their symbiotic bacteria. Results: The newly discovered species, Heterorhabditis casmirica n. sp., shares 94% mitochondrial cytochrome C oxidase subunit I gene (COI) sequence identity with Heterorhabditis bacteriophora and Heterorhabditis ruandica, and 93% with Heterorhabditis zacatecana. Morphologically, it differs from H. bacteriophora in its infective juvenile phasmids (present vs. inconspicuous) and bacterial pouch visibility in the ventricular portion of the intestine (invisible vs. visible); genital papilla 1 (GP1) position (at manubrium level vs. more anterior), and in its b ratio (body length/neck length), c ratio (tail length/bulb width), and D% [(excretory pore/neck length) × 100]. Other morphological differences include anterior end to the nerve ring distance (77–100 vs. 121–130 μm), V% [(anterior end of vulva/body length) × 100] (46–57 vs. 41–47) in hermaphroditic females; rectum size (slightly longer than the anal body diameter vs. about three times longer), phasmids (smaller vs. inconspicuous), body length (0.13–2.0 vs. 0.32–0.39 mm), body diameter (73–150 vs. 160–220 μm), anterior end to the excretory pore distance (135–157 vs. 174–214 μm), and demanian ratios in amphimictic females. Morphological differences with H. ruandica and H. zacatecana were also observed. Furthermore, H. casmirica n. sp. did not mate or produce fertile progeny with other Heterorhabditis nematodes reported from India. It was also discovered that H. casmirica n. sp. is associated with Photorhabdus luminescence subsp. clarkei symbiotic bacteria. Conclusions: The discovery of H. casmirica n. sp. provides novel insights into the diversity and evolution of Heterorhabditis nematodes and their symbiotic bacteria. This new species adds to the catalog of entomopathogenic nematodes in India. [ABSTRACT FROM AUTHOR]

Alternatives to hazardous insecticides are urgently needed for an environmentally friendly and effective management of insect pests. One such option is the use of entomopathogenic nematodes (EPN). To increase the availability of EPN with potential for biocontrol, we surveyed agricultural soils in the Republic of Rwanda and collected two Steinernema isolates. Initial molecular characterization showed that they represent a new species, for which we propose the name S. africanum n. sp. To describe this new species, we reconstructed phylogenetic relationships, calculated sequence similarity scores, characterized the nematodes at the morphological level, conducted crossing experiments, and isolated and characterized their symbiotic bacteria. At the molecular level, S. africanum n. sp. is closely related to S. litorale and S. weiseri. At the morphological level, S. africanum n. sp. differs from closely related species by the position of the nerve ring and also because the stoma and pharynx region is longer. The first-generation males have ventrally curved spicules with lanceolate manubrium and fusiform gubernaculum and the second-generation males have rounded manubrium and anteriorly hook-like gubernaculum. Steinernema africanum n. sp. does not mate or produce fertile progeny with any of the closely related species.

Summary: Two populations of bacterial-feeding nematodes belonging to the genus Panagrolaimus were recovered from infected slugs collected from gardens, agricultural areas and nurseries of the Baghpat district (India). Initial morphological characterisation of these populations show that they resemble Panagrolaimus labiatus from China and Bulgaria, P. burdwanensis from India, and P. cf. labiatus from Iran. To clarify taxonomical affiliations, we morphologically compared these two new populations to those recovered from China, Bulgaria, India and Iran. In addition, we sequenced several taxonomically relevant genes and used them to reconstruct phylogenetic relationships. Our results show that the two Indian populations do not significantly differ morphologically from the specimens used to describe the species P. labiatus , and also do not differ among them. We only observed small variations in the size of males and females. In addition, morphologically, the nematodes used to describe P. burdwanensis are very similar to the nematodes used to describe P. labiatus and to the two populations described in this study. Therefore, we propose P. burdwanensis as a junior synonym of P. labiatus and that the two populations recovered from India belong to the P. labiatus species. Phylogenetic analyses using the nucleotide sequences of the internal transcribed spacer (ITS), 18S and 28S rRNA gene sequences support our morphological conclusions. Our study therefore provides a detailed morphological description and molecular marker 18S and 28S gene sequences that can support future taxonomical studies of this species and highlights the importance of using both molecular and morphological data for the proper description of soil microfauna. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agriculture & Nature / Kahramanmaraş Sütçü İmam Üniversitesi Tarım & Doğa Dergisi is the property of Kahramanmaras Sutcu Imam Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Caenorhabditis auriculariae, which was morphologically described in 1999, was re-isolated from a Platydema mushroom-associated beetle. Based on the re-isolated materials, some morphological characteristics were re-examined and ascribed to the species. In addition, to clarify phylogenetic relationships with other Caenorhabditis species and biological features of the nematode, the whole genome was sequenced and assembled into 109.5 Mb with 16,279 predicted protein-coding genes. Molecular phylogenetic analyses based on ribosomal RNA and 269 single-copy genes revealed the species is closely related to C. sonorae and C. monodelphis placing them at the most basal clade of the genus. C. auriculariae has morphological characteristics clearly differed from those two species and harbours a number of species-specific gene families, indicating its usefulness as a new outgroup species for Caenorhabditis evolutionary studies. A comparison of carbohydrate-active enzyme (CAZy) repertoires in genomes, which we found useful to speculate about the lifestyle of Caenorhabditis nematodes, suggested that C. auriculariae likely has a life-cycle with tight-association with insects. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity is one of the most important strategies used by organisms with low mobility to survive in fluctuating environments. Phenotypic plasticity plays a vital role in nematodes because they have small bodies and lack wings or legs and thus, cannot move far by themselves. Bursaphelenchus xylophilus, the pathogenic nematode species that causes pine wilt disease, experiences fluctuating conditions throughout their life history; i.e., in both the phytophagous and mycetophagous phases. However, whether the functional morphology changes between the life phases of B. xylophilus remains unknown. Our study revealed differences in the ultrastructure of B. xylophilus between the two phases. Well-developed lateral alae and atrophied intestinal microvilli were observed in the phytophagous phase compared with the mycetophagous phase. The ultrastructure in the phytophagous phase was morphologically similar to that at the dauer stage, which enables the larvae to survive in harsh environments. It suggests that the living tree represents a harsh environment for B. xylophilus, and ultrastructural phenotypic plasticity is a key strategy for B. xylophilus to survive in a living tree. In addition, ultrastructural observations of obligate plant-parasitic species closely related to B. xylophilus revealed that B. xylophilus may be in the process of adapting to feed on plant cells. [ABSTRACT FROM AUTHOR]

• The first molecular analysis and phylogenetic positioning of Physaloptera mirandai. • P. mirandai promote lesions in stomach tissue during the parasitism. • Measurement of taxonomic characters were introduced by 3D reconstruction and modeling. • New structural organization and number of cloacal papilla was presented. Gastrointestinal nematodes are important ecological assets for the maintenance of the biodiversity in the Atlantic Forest in Brazil. They parasitize a number of animals of the local fauna, in which some species can promote serious injuries in the stomach wall of their hosts, which may lead to death. Among these nematodes, parasites of the genus Physaloptera are known to parasitize mammals (particularly carnivores and small rodents), birds and reptiles, being important for the local biodiversity. In this work, three hundred and sixty-two nematodes were recovered from the stomach of twenty-one Metachirus nudicaudatus (Didelphimorphia: Didelphidae) collected in Duas Bocas Biological Reserve, State of Espírito Santo, one of the largest Atlantic Forest remnants and important wildlife refuge of the Atlantic Forest in Brazil. Analysis using fluorescence and scanning electron microscopy as well as phylogenetic assessment using the mitochondrial cytochrome c oxidase subunit I gene showed that the parasites belong to the Physaloptera. Our results show details of the nematode morphology including the cloacal papillae distribution, cuticular topography details, 2D and 3D measurements of the structures with taxonomic importance. Molecular data confirmed the validity of P. mirandai and the phylogeny supported the monophyly of the assemblage formed by Physaloptera and Turgida. The use of a combination of quantitative and multidimensional microscopy tools, such as 3D reconstruction and modeling, allied to phylogenetic analysis may provide grounds for a new approach on helminth taxonomy and structural characterization. [ABSTRACT FROM AUTHOR]

Bakernema enormese sp. n., collected from rhizosphere of forest wood trees in Muong Phang, Dien Bien Province (north Vietnam) is described and illustrated. The new species is characterized by large body size and stylet. In general, this new species is close to two existing species of the same genus, B. inaequale and B. dauniense by cuticle structure in transparent membranous projections which appear in lateral view as spine-like structures on each annulus. These structure arranged into several rows along the body. In morphology, the new species differs from B. inaequale and B. dauniense by body and stylet length, i.e. 609-842 µm and 143.5-150 µm vs. 391-578 µm and 59-74 µm for B. inaequale and vs. 391-461µm and 65-74 µm for B. dauniense. In addition, new species can be distinguished from B. inaequale by the longer membranous projection, 8-12 vs. 6-10 µm and vagina shape, curved vs. sigmoid. From B. dauniense, the new species differs by the much longer membranous projection, 8-12 vs. 1.4-2.2 µm and less number annules between vulva and tail end (RV), 3-4 vs. 7.8 annules. The presence of Criconema (Nothocriconemella) graminicola Loof, Wouts & Yeates, in Vietnam with morphometrics, illustrators and remarks given. [ABSTRACT FROM AUTHOR]

Background: Understanding the cellular architecture is a fundamental problem in various biological studies. C. elegans is widely used as a model organism in these studies because of its unique fate determinations. In recent years, researchers have worked extensively on C. elegans to excavate the regulations of genes and proteins on cell mobility and communication. Although various algorithms have been proposed to analyze nucleus, cell shape features are not yet well recorded. This paper proposes a method to systematically analyze three-dimensional morphological cellular features. Results: Three-dimensional Membrane Morphological Segmentation (3DMMS) makes use of several novel techniques, such as statistical intensity normalization, and region filters, to pre-process the cell images. We then segment membrane stacks based on watershed algorithms. 3DMMS achieves high robustness and precision over different time points (development stages). It is compared with two state-of-the-art algorithms, RACE and BCOMS. Quantitative analysis shows 3DMMS performs best with the average Dice ratio of 97.7% at six time points. In addition, 3DMMS also provides time series of internal and external shape features of C. elegans. Conclusion: We have developed the 3DMMS based technique for embryonic shape reconstruction at the single-cell level. With cells accurately segmented, 3DMMS makes it possible to study cellular shapes and bridge morphological features and biological expression in embryo research. [ABSTRACT FROM AUTHOR]

Porrocaecum semiteres (Zeder, 1800) (Ascaridida: Ascaridoidea) occurs frequently in various birds in Europe. However, the knowledge of the morphology of this species remains insufficient. Light and scanning electron microscopy were used to study the detailed morphology of adults of P. semiteres based on newly collected specimens from Turdus philomelos in the Czech Republic. Some previously unreported morphological features were revealed, including the presence of a medio-apical notch, 70–80 small conical denticles and one pair of submedial pores on each lip, the absence of caudal alae, the presence of four pairs of postcloacal papillae, and a single, medio-ventral precloacal papilla. [ABSTRACT FROM AUTHOR]

The genus Rhabdochona includes more than 100 species infecting freshwater fishes in all zoogeographical regions of the world. In Mexico, 12 nominal species of Rhabdochona have been recorded. Of these, Rhabdochona ictaluri was originally described as a parasite of endemic catfishes of the family Ictaluridae; however, the species was later considered on morphological grounds as a junior synonym of Rhabdochona kidderi. In this study, newly sampled specimens of R. ictaluri were obtained from the type host and type locality and were used to perform a detailed morphological analysis and molecular phylogenetic inferences through one mitochondrial and two nuclear genes; data were used in an integrative taxonomy context to test the taxonomic status of R. ictaluri. This approach proved to be very useful to confirm the validity of this species, and robust species limits were established between these two putative species considering morphology, molecular data, host association, and biogeography. [ABSTRACT FROM AUTHOR]

Highlights • The influence of HPA on benthic assemblages was investigated. • The study focused on functional patterns of nematodes and macrobenthos. • Benthic samples were collected near and far from an oil refinery. • Functional variation was explained by natural and anthropogenic factors. • BTA is an important tool for detection of anthropogenic variations. Abstract The potential effects of perturbations by Polycyclic Aromatic Hydrocarbons (PAHs) on nematode and macrobenthos assemblages were investigated using the Biological Traits Analysis (BTA). We sampled at tidal flats near an oil refinery and in a reference estuary. Morphological and ecological traits of benthic fauna were selected and analyzed in order to assess the contribution of PAHs concentrations, the proximity to the oil refinery, the sediment characteristics and interaction between these predictor variables on benthic fauna. Multivariate analyses (DISTLM and db-RDA), showed that a large fraction of functional and taxonomic variation of benthic assemblages was explained by the interaction between location and sediment characteristics. The interaction between ∑PAHs and sediment characteristics was relatively low but significant. The results showed that taxonomic and functional variability of benthic assemblages were driven by natural and anthropogenic variables and BTA was an important auxiliary tool for distinguishing these responses. The amount of variability explained by the model was higher for nematode assemblages than to macrofaunal assemblages, showing a potential higher sensitivity of this group to the predictor variables. [ABSTRACT FROM AUTHOR]

Digenea usually use ventral sucker for sustainable attachment within intestine of their definitive vertebrate host. However, if the ventral sucker is absent or poorly developed, the means of attachment are unclear. We investigated attachment and locomotion in such digeneans: three species of the family Microphallidae (Microphallus piriformes, M. pygmaeus, and Levinseniella brachysoma) and two species of the family Heterophyidae (Cryptocotyle concava and C. lingua). Their tegumental spines and musculature were described with use of fluorescent actin staining, confocal microscopy, and scanning electron microscopy. Locomotion of living worms was observed and recorded. Wide serrated tegumental spines probably play the main role in attachment. Their firm contact with the host mucosa may be provided by the action of the ventral concavity—when the entire body or its part acts as a sucker. Dorsoventral muscle bundles act like radial musculature of the sucker generating negative pressure in the ventral concavity. The solid layer of longitudinal muscle fibers on the ventral body surface provides support for the bottom of the ventral concavity. In all microphallids, a U-shaped arrangement of body wall musculature (mostly originating from longitudinal fibers) outlines posterior part of the ventral concavity ridge. In all the studied species, tegumental spines, body wall musculature, and dorsoventral muscle bundles are better developed in the forebody which moves more actively than the hindbody. [ABSTRACT FROM AUTHOR]

The root-lesion nematode of the genus Pratylenchus Filipjev (1936) has a worldwide distribution and cause severe production constraints on numerous important crops. In 2013-14, during a survey of the apple nurseries and orchards in center of Tunisia (Kairouan, Zaghouan, Monastir and Kasserine), 70 different roots and soil samples were collected. The populations of root-lesion nematode were identified on the basis of their morphological and morphometric characters, and by molecular methods. Microscopic observation of females and males demonstrated the occurrence of Pratylenchusd vulnus on apple trees. The ribosomal DNA D2-D3 expansion segments of the 28S rRNA and of the Pratylenchus populations were PCR amplified and sequenced. The sequences were compared with those of Pratylenchus species in the GenBank database with high similarity (99%). This comparison reconfirmed the morphological identifications. Phylogenetic studies placed those populations with P. vulnus. This is the first report of P. vulnus infecting apple in Tunisia. [ABSTRACT FROM AUTHOR]

Juvenile, female and male nematodes were discovered in wood chips of white pine Pinus strobus from Ashley Falls, MA. Initial observations suggested these nematodes might be PWN, but closer morphological and molecular characterization proved otherwise. Comparison of measured features with those in the literature indicated this nematode population had some unique characteristics. The specimens were identified as Bursaphelenchus antoniae Penas et al., 2006 based on 18S rDNA molecular sequence vs only 95% similarity with PWN B. xylophilus. Compared to the previously described Portuguese population of B. antoniae, the sequences generated for the MA population were 98.3% similar in the ITS1, 2 rDNA and 99.9% similar for 28S rDNA. There was 99.2% similarity between the COI sequences of the US and Portuguese isolates of B. antoniae. This population has morphology consistent with that of Penas et al., 2006; however, the female tail on this MA pine population is mucronate and more attenuated than in B. antoniae from Portuguese P. pinaster found in association with Hylobius sp. Ecological associations of both populations of B. antoniae are discussed. [ABSTRACT FROM AUTHOR]

In this study juvenile stages of Bursaphelenchus crenati (Sexdentati group) were distinguished based mainly on the genital primordium structure. Dauer stage juveniles were sampled under elytra of Hylesinus crenatus in galleries in bark of the wilted Fraxinus excelsior in the Voronezh region of Russia and were multiplied in laboratory cultures on the fungus Botrytis cinerea. Individual development included five stages (J1 - J4 and adults) separated by molts. The first molt J1 to J2 occurred inside the egg and the J2 was at the hatching stage. Sex of juvenile stages can be identified using the morphology and size of the genital primordia and a body size of nematodes. Sex of juveniles may be identified from the J3 stage by the presence of the cloacal primordium in male juvenile and orientation of the germinal zone of the genital primordium. A tabular key to developmental stages of B. crenati is given. The body grows during molts and within each stage. The body increases rapidly after J3 stage combined with the most active cellular differentiation and elongation of the genital primordium. The dauer juveniles collected from elytra of vector beetles were similar to the third juvenile stage of the propagative generation by genital primordium structure and body size. [ABSTRACT FROM AUTHOR]

Gracilacus paralatescens n. sp., isolated in Anji County, Zhejiang Province, China from the rhizospheric soil of bamboo. The new species can be characterized by the female lateral field with three incisures, stylet 71.5 to 78.8 μm long, lip region truncated, excretory pore located anterior to basal knobs. Vulval lips non-protruding and without vulval flap, spermatheca large, elongated squarish shaped filled with sperms. Tail slender, relatively straight having wedge shape terminus. The spicule slender, slightly curved and 17.5 to 18.9 μm long. In the phylogenetic analysis based on 18S, D2-D3 of 28S and ITS regions of rDNA, the new species is clustered with Paratylenchid species having longer stylet length. Morphologically, the new species belongs to Group 9 of Paratylenchus sensu lato and is most similar to G. latescens. [ABSTRACT FROM AUTHOR]

A new species belonging to the genus Belondira is described from natural areas in Iran. Belondira coomansi n. sp. is characterized by its general size, the dimensions and appearance of its lip region, presence of distinct labial and post-labial sclerotization, the length of the odontostyle and its inconspicuous lumen and aperture, the length of the neck and its pharyngeal expansion, the reduction of the female anterior genital branch to a simple uterine sac, a very short posterior uterus, the anterior position of the vulva, the length and shape of the caudal region with distinctly thick cuticle at its tip, the length of the spicules, and the presence of only one pair of ventromedian supplements. The new species is close to Belondira brevibulba, B. sacchari , B. tenuidens and B. thornei , and it is compared to them. Molecular characterization (D2–D3 expansion segments of the rRNA large subunit) of the new species is also provided, representing only the second species of this genus for which any DNA sequence data are available. [ABSTRACT FROM AUTHOR]

A new plant nematode species, Trophurus wuhuensis n. sp., was collected from the soil associated with Cinnamomum camphora in Wuhu, Anhui Province, China. The new species is characterized by having a female with a slender body 660.5–801.5 μm in length, stylet 12–14 μm long, knobs directed laterad, lateral field marked by short and scattered grooves, post-vulval uterine sac shorter than vulval body diameter, post-rectal intestinal sac absent, tail cylindroid, terminus with deep wrinkles; and male with a pointed tail terminus and spicules 16–18 μm long. The internal transcribed spacer sequences of ribosomal DNA (ITS rDNA) and partial 18S ribosomal DNA (18S rDNA) from T. wuhuensis n. sp. were amplified and sequenced. A phylogenetic analysis based on sequences of 18S rDNA fragments is given in this study. [ABSTRACT FROM AUTHOR]

As a result of the scarcity of informative morphological and anatomical characters, nematode systematics have always been volatile. Differences in the appreciation of these characters have resulted in numerous classifications and this greatly confuses scientific communication. An advantage of the use of molecular data is that it allows for an enormous expansion of the number of characters. Here we present a phylogenetic tree based on 1215 small subunit ribosomal DNA sequences (ca 1700 bp each) covering a wide range of nematode taxa. Of the 19 nematode orders mentioned by De Ley et al. (2006) 15 are represented here. Compared with Holterman et al. (2006) the number of taxa analysed has been tripled. This did not result in major changes in the clade subdivision of the phylum, although a decrease in the number of well supported nodes was observed. Especially at the family level and below we observed a considerable congruence between morphology and ribosomal DNA-based nematode systematics and, in case of discrepancies, morphological or anatomical support could be found for the alternative grouping in most instances. The extensiveness of convergent evolution is one of the most striking phenomena observed in the phylogenetic tree presented here - it is hard to find a morphological, ecological or biological characteristic that has not arisen at least twice during nematode evolution. Convergent evolution appears to be an important additional explanation for the seemingly persistent volatility of nematode systematics. [ABSTRACT FROM AUTHOR]

A solution containing dimethyl sulphoxide, disodium EDTA, and saturated NaCl (abbreviated here as DESS) was tested for various applications in the preservation of nematodes for combined morphological and molecular analyses. The solution can be used to preserve individual nematodes, nematode extracts, or entire soil/sediment samples. Preserved material can be easily stored for months at room temperature, shipped by mail, or carried in luggage. Morphological features are usually well preserved; specimen quality being comparable to formalin-based fixatives and much better than ethanol fixation. Specimens can be transferred to glycerin with little or no modification of traditional protocols. Unlike formalin-preserved material, routine PCR can be performed on individual specimens after any of these procedures with success rates and amplification sizes comparable to PCR of fresh specimens. At this point we have no data on long-term preservation quality. Nevertheless, DESS solution clearly enhances and simplifies a wide range of nematological studies due to its combined suitability for morphological and molecular analyses, as well as its less hazardous chemical properties. [ABSTRACT FROM AUTHOR]

A survey of aphelenchid nematodes (Nematoda: Aphelenchida) associated with maritime pine, Pinus pinaster, was conducted in Portugal in 1996 and 1999. A Bursaphelenchus species has been identified for the first time in the Iberian Peninsula. B. xylophilus is reported for the first time in Europe. It was found in very high numbers - up to 38 000 per 10 g of pine wood - inside a few declining trees infested with curculionid, cerambycid and scolytid beetles. Morphological observations, including shape of spicules, bursa, vulva, female tail end and stylet as well as morphometrics, were in accordance with the species description. Speciesspecific DNA fragment patterns were obtained using ITS-RFLP analysis, with five different restriction enzymes. The importance and implications of this finding are discussed. [ABSTRACT FROM AUTHOR]

Tripylella jianjuni sp. n. (Tripylidae) is described from New Zealand. Females are characterised by a relatively long body (1743 (1675-1860) μm in the female and 1747 (1576-1979) μm in the male), outer labial setae (8-9 μm long) and cephalic setae (4-5 μm long) in a single circle, two large subventral teeth in two adjacent stomatal chambers, relatively short pharynx (b = 5.5 (5.4-5.6) in the female and 5.7 (5.3-6.1) in the male), vulva located slightly anterior to mid-body (V = 44 (43-46)), protuberant lips, and long filiform tail (461 (398-531) μm, c = 3.8 (3.3-4.2) and c' = 23.2 (18-29) in the female, and 450 (362-511) μm, c = 3.9 (3.6-4.4) and c' = 19.0 (16.0-20.8) in the male), tail with three ventromedian caudal setae. Males have arcuate spicules 37 (35-41) μm long, gubernaculum straight, 14 (12-16) μm long, three ventromedian supplementary papillae located anterior to the cloacal aperture, and a single plus four pairs of subventral caudal setae located posterior to the cloacal aperture on the tail. Preliminary analyses of phylogenetic relationships within the Triplonchida were done using the SSU and D2-D3 region of LSU DNA sequences. [ABSTRACT FROM AUTHOR]

Pratylenchus rwandae n. sp., a root-lesion nematode associated with maize (Zea mays) from Rwanda, is described. This new species is characterised by females of medium to large size (469-600 μm) having an offset lip region with three annuli, stylet of 13-14.6 μm long with prominent rounded or anteriorly concave knobs, short to long pharyngeal gland overlap of 10.9-34.7 μm long, variable number of lateral lines (4-14) in different regions of the body, lateral field consisting of smooth bands, oval to slightly rounded spermatheca, vulva located at 75-80% of the total body length, post-vulval uterine sac (PUS) 20.3-26.5 μm long, tail subcylindrical to conoid with variation in tail tip shape from rounded to truncate or indented with generally smooth tip, and male unknown. The results of the phylogenetic analyses based on sequences of the D2-D3 expansion regions of 28S, partial 18S and ITS of rDNA and COI of mitochondrial DNA indicate that P. rwandae n. sp. is a species within the Penetrans group and appears as a sister species to a group comprising P. convallariae, P. dunensis, P. fallax, P. oleae, P. penetrans, P. pinguicaudatus, and three other unidentified species. A comparison of important morphological characters of the closely related Pratylenchus spp. is provided. [ABSTRACT FROM AUTHOR]

The mucron in male steinernematid nematodes may be missing or present either in the first or second generation, or missing in both generations, with variable shape. However, for many species, the information on mucron morphology is incomplete and its taxonomic significance and distribution remain unclear. The present study assessed mucron morphology in males of 26 species using LM and SEM microscopy. For other species we summarised the published data. Furthermore, ancestral character state reconstruction analysis was performed to assess the distribution of mucron morphology within steinernematid phylogeny. In most species, papilla/spine-like or filamentous mucrons occur at least in the second generation. The species gathered in single phylogenetic groups have a similar mucron morphology. Generally, species with a prominent filamentous mucron belong to the 'kraussei/feltiae' and 'carpocapsae' groups, whereas mostly non-mucronated species occur in 'glaseri' and 'riobrave' groups. For future descriptions a precise mucron characterisation in both generations of the male is recommended. [ABSTRACT FROM AUTHOR]

Introduction: Toxocara canis and Toxocara cati are roundworms of dogs and cats. The purpose of this study was to investigate the infection caused by these ascarids in cats and dogs, using microscopic and molecular analysis methods. Material and Methods: Adult ascarids were gathered from the faeces of dogs and cats in Van province, in 2015-2016. Existing keys and PCR sequencing of the ITS-2 fragment were used to identify the morphological features of the parasite species. Results: It was observed that out of 20 adult ascarids, 17 and 3 were found to be Toxocara canis and Toxocara cati, respectively. The ITS-2 gene region was amplified by PCR to perform molecular analysis. Genotyping indicated that the dogs and cats were infected with T. canis and T. cati, respectively, and none had Toxascaris leonina. Conclusion: To the best of our knowledge, this is the first report on the molecular characteristics of adult ascaridoid nematodes from cats and dogs in Turkey. The molecular approaches established in this study enable molecular identification and genetic structure studies of the ascaridoids. [ABSTRACT FROM AUTHOR]

Longidorus pinus sp. n. from China is characterised by females 3.3-4.9 mm long; lip region 8-12 μm diam., distinctly offset by a constriction; amphidial fovea pocket-shaped without basal lobes; a short odontostyle (67-81 μm); anteriorly located guide ring (30-38 μm); and short and conoid tail (31-40 μm long, c = 84-138, c′ = 1.2-1.9), with one or two pairs of caudal pores on each side. Males were not found. Three developmental juvenile stages were identified, the first-stage juvenile with conoid tail (c′ = 2.4-2.9). The polytomous key codes for the new species are: A2(3), B1, C23, D4, E1, F2, G23, H23, I1, J2, K6. Molecular phylogenetic analyses based on SSU, D2-D3 of LSU, ITS1 and ITS2 rDNA sequences indicate that L. pinus sp. n. is closely related to L. hangzhouensis, L. asiaticus, and L. camelliae, all of which apparently share a common Asiatic geographic origin. In addition, a key for identification of Longidorus found in China, based on morphological characters of both female and first-stage juvenile, is provided. [ABSTRACT FROM AUTHOR]

The first integrative approach using sequences of two genes (18S and 28S rRNA) plus morphological and life history traits, was explored in Pharyngodonidae nematodes parasitic in reptiles. Additionally, first genetic characterization of Parapharyngodon bainae and new data on its morphology are given. This approach evaluated the phylogenetic relationships among genera within Pharyngodonidae, as well as the importance of their diagnostic morphological features. Specimens of P. bainae were collected from faecal pellets of the lizard Tropidurus torquatus in the State of Minas Gerais, Brazil. Nematodes were fixed for scanning electron microscopy and molecular procedures. Morphological observations revealed the accurate structures of cephalic end, of cloacal region in males, of vulva and eggs. Phylogenetic reconstructions were based upon four datasets: aligned sequences of the 18S, of the 28S, of both concatenated genes and of combined morphological and molecular datasets. Bayesian inference and maximum likelihood were performed to infer the phylogenies of molecular datasets and maximum parsimony to infer that of all-combined data. Pharyngodonid parasites of reptiles seem to configure two general monophyletic lineages, as previously assertions. Results also showed the monophyly of Spauligodon, Skrjabinodon and Parapharyngodon, as well as the clear separation between the latter and Thelandros. Combination of datasets improved nodal supports. Analysis of the all-combined datasets revealed the importance of vulval position and egg morphology as phylogenetic informative traits. However, characters of male caudal morphology appear as are highly homoplastic, and seem to be product of convergent evolution or multiple losses of ancestral traits. The closely-related Thelandros and Parapharyngodon are kept valid and their diagnosis should be based upon the position of the operculum in eggs (terminal or subterminal, respectively). Some inconsistencies in the scarce molecular and morphological databases were noted. Thus, new genetic data is required for further conclusions and current database must be evaluated with attention. [ABSTRACT FROM AUTHOR]

A new nematode species of the genus Parasitodiplogaster was recovered from syconia of Ficus religiosa at the Guangxiao Temple, Guangzhou, China. It is described herein as P. religiosae n. sp. and is characterised by possessing the longest and thinnest spicule of all currently described males in the genus, an elongated laterally “ε-shaped” and ventrally rhomboid-like gubernaculum, a stoma without teeth, consisting of a ring-like cheilostom with indistinct anteriolateral projections, a tube-like gymnostom and a funnel-like stegostom, monodelphic with a mean vulval position of 66%. There are three pre-cloacal and six post-cloacal male genital papillae with the arrangement P1, P2, P3, (C, P4), P5, P6d, P7, P8, P9d, Ph. This new species was easily differentiated from other members of the genus by DNA sequences of partial small subunit rRNA gene (SSU) and the D2-D3 expansion segments of the large subunit rRNA gene (LSU). Phylogenetic analysis also corroborated its reasonable placement within a well-supported monophyletic clade with other Parasitodiplogaster species and within the australis-group that includes P. australis and P. salicifoliae that are all associates of fig wasp pollinators (Platyscapa sp.) of figs of the subsection Urostigma. [ABSTRACT FROM AUTHOR]

In this study, we present a scheme for the reconstruction of cellular morphology and the inference of mechanical forces in the early C. elegans embryo. We have developed and bench-marked a morphological reconstruction scheme that transforms flourescence-based in vivo images of membranes into a point cloud of smoothed surface patches, which facilitates an accurate estimation of membrane curvatures and the angles between membranes. Assuming an isotropic and homogeneous distribution of tensions along individual membranes, we infer a pattern of forces that are 7% deviated from force balance at edges, and 10% deviated from the Young-Laplace relation across membranes. We demonstrate the stability of our inference scheme via a sensitivity analysis, and the reproducibility of our image-analysis and force inference pipelines. [ABSTRACT FROM AUTHOR]

The genus Cooperia includes important parasites of ruminants and currently contains 34 accepted species. However, even for those species infecting livestock, there is a considerable lack of molecular information and many species are only identifiable using subtle morphological traits. The present study aimed to provide molecular data to allow diagnosis of Cooperia species infecting cattle. Partial sequences of two mitochondrial (cytochrome oxidase 2, 12S rRNA gene) and two nuclear genes (isotype 1 β tubulin gene including two introns, internal transcribed spacers (ITS) were obtained from morphologically identified specimens of Cooperia pectinata, Cooperia punctata and Cooperia spatulata as well as from larvae of pure Cooperia oncophora and C. punctata laboratory isolates. Pairwise identity of ITS-2 sequences was very high and it was the only region able to identify a specimen as Cooperia sp. However, the ITS-2 was unreliable for diagnosis at the species level. All other marker sequences could not unequivocally be allocated to the genus Cooperia but allowed clear species identification with the exception of the pair C. punctata/C. spatulata for which no significant differences were found for any marker sequence. Maximum-likelihood phylogenetic analyses of individual genes as well as a multi-locus analysis covering all four sequences confirmed that specimen identified as C. spatulata were randomly distributed throughout the C. punctata cluster and formed no group of their own. In contrast, the other Cooperia species formed clearly separated and statistically supported clusters. These data indicate that C. spatulata is most likely only a morphotype of C. punctata and the name should be considered a synonym. Combinations of nuclear and mitochondrial markers should be used to identify morphotypes or cryptic species to benefit from excellent barcoding properties of the latter but allowing proper phylogenetic analyses and controlling for lineage sorting that might occur for mitochondrial genotypes within a species. [ABSTRACT FROM AUTHOR]

In this study, we describe a morphological biomarker that detects multiple discrete subpopulations (or "age-states") at several chronological ages in a population of nematodes (Caenorhabditis elegans). We determined the frequencies of three healthy adult states and the timing of the transitions between them across the lifespan. We used short-lived and long-lived strains to confirm the general applicability of the state classifier and to monitor state progression. This exploration revealed healthy and unhealthy states, the former being favored in long-lived strains and the latter showing delayed onset. Short-lived strains rapidly transitioned through the putative healthy state. We previously found that age-matched animals in different age-states have distinct transcriptome profiles. We isolated animals at the beginning and end of each identified state and performed microarray analysis (principal component analysis, relative sample to sample distance measurements, and gene set enrichment analysis). In some comparisons, chronologically identical individuals were farther apart than morphologically identical individuals isolated on different days. The age-state biomarker allowed assessment of aging in a novel manner, complementary to chronological age progression. We found hsp70 and some small heat shock protein genes are expressed later in adulthood, consistent with the proteostasis collapse model. [ABSTRACT FROM AUTHOR]

Labrys filiformis n. sp., the second species of the rare genus Labrys, was recovered from natural forests of Gilan province and is described based upon morphological and molecular characters. The new species is characterized by its smooth cuticle under light microscopy, lateral field with two incisures forming a single plain band, lip region continuous with body contour, dorso-ventrally flattened and forming four poorly prominent lobes, having a dorso-ventrally narrower protuberant labial plate laterally extended to the amphidial margins, oral area (oral plate) dorso-ventrally elongated and embedded in the labial plate with six small labial sensilla surrounding the slightly prominent oral aperture, amphidial apertures as longitudinally lemniscatic slits bordered by the labial plate extensions which are overlapped at the middle length of amphids, stylet delicate, 6 to 7 μm long, elongate weakly developed fusiform median bulb with weak valve, wide excretory pore with long and heavily sclerotized duct, offset spermatheca filled with small spheroid sperm cells, 106 to 127 μm long elongate-conoid tail with filiform distal region and finely rounded tip. Molecular phylogenetic analyses were performed using a near-full length fragment of the 18S rDNA and the D2-D3 expansion segments of the 28S rDNA using Bayesian inference and maximum likelihood methods. In the inferred phylogenetic tree with 18S rDNA, the new species has a close affinity with several isolates of the type species, Labrys chinensis. The reconstructed phylogenetic tree using partial 28S rDNA, revealed the new species is nested inside the putative monophyletic group of several populations of L. chinensis. [ABSTRACT FROM AUTHOR]

Pristionchus pacificus Sommer, Carta, Kim, and Sternberg, 1996 is an important model organism in evolutionary biology that aims to integrate developmental biology and evo-devo with population genetics and ecology. Functional studies in P. pacificus are supported by a well-established phylogenetic framework of around 30 species of the genus Pristionchus that have been described in the last decade based on their entomophilic and necromenic association with scarab beetles. Biogeographically, East Asia has emerged as a hotspot of Pristionchus speciation and recent samplings have therefore focused on Islands and mainland settings in East Asia. Here, we describe in a series of three publications the results of our sampling efforts in Taiwan, Japan, and Hongkong in 2016 and 2017. We describe a total of nine new species that cover different phylogenetic speciescomplexes of the Pristionchus genus. In this first publication, we describe two new species, Pristionchus sikae sp. n. and Pristionchus kurosawai sp. n. that are closely related to P. pacificus. Together with five previously described species they form the "pacificus speciescomplex sensu stricto" that is characterized by all species forming viable, but sterile F1 hybrids indicating reproductive isolation. P. sikae sp. n. and P. kurosawai sp. n. have a gonochorist mode of reproduction and they are described using morphology, morphometrics, mating experiments, and genome-wide sequence analysis. We discuss the extreme diversification in the pacificus species-complex sensu stricto in East Asia and its potential power to study speciation processes. [ABSTRACT FROM AUTHOR]

One new and one known species of the genus Aphelenchoides from Iran are studied. Aphelenchoides giblindavisi n. sp. is mainly characterized by having five lines in the lateral fields at mid-body, and a single mucro with several tiny nodular protuberances, giving a warty appearance to it, as revealed by detailed scanning electron microscopic (SEM) studies. The new species is further characterized by having a body length of 546 to 795 μ m in females and 523 to 679 μ m in males, rounded lip region separated from the rest body by a shallow depression, 10 to 11 μm long stylet with small basal swellings, its conus shorter than the shaft (m = 36-43), 52 to 69 μm long postvulval uterine sac (PUS), males with 16 to 18 μ m long arcuate spicules, and three pairs of caudal papillae. The new species was morphologically compared with two species of the genus having five lines in the lateral fields namely A. paramonovi and A. shamimi and species having a warty-surfaced mucro at tail end and similar morphometric data ranges. The morphological features and morphometrics of the second studied species, A. helicus, agreed well with the data given for the type population. However, detailed study of fresh females revealed it has three drop-shaped stylet knobs and long PUS, making it typologically similar to the genus Robustodorus, meriting its taxonomic revision, i.e., transferring to it. In molecular phylogenetic analyses using partial small and large subunit ribosomal RNA gene (SSU and LSU rDNA) sequences, the new species formed a clade with A. heidelbergi in both SSU and LSU D2-D3 trees. The species A. helicus, however, clustered inside a well-supported clade of the genus Robustodorus in both trees, corroborating its newly proposed taxonomic placement as Robustodorus helicus n. comb. [ABSTRACT FROM AUTHOR]

Xiphinema parachambersi n. sp. recovered in Ningbo, China, from the rhizosphere of ornamental plants (Gardenia jasminoides and Euonymus hamiltonianus) imported from Japan is described. The new species is characterized by a long female body 1,830 to 2,109 μm long, odontostyle 105 to 116 μm long, reproductive system monoopisthodelphic, vulva located anteriorly at 25.2 to 27.7% of total body, long ovary 119 to 292 μm with simple uterus and Z-organ absent, female tail elongated conoid with a rounded terminus. Only two juvenile stages were available to study and no male was found. The polytomous identification codes for this new species are A1, B4, C2, D23, E1, F2, G2, H2, I2, J2, K?, L1 and it belongs to the morphospecies group 1. Phylogenetic analysis based on the 18S, ITS1 and 28S D2/D3 sequences of the new species showed close relationships with X. chambersi. Morphologically, the new species is similar to X. chambersi, X. hangzhouense, and X. winotoi but can be differentiated by morphological characters and DNA sequences. To help identify the species, a diagnostic key to the group 1 species is presented. [ABSTRACT FROM AUTHOR]

Nematode samplings in cultivated and wild olive in Crete, Greece, yielded the presence of Bitylenchus hispaniensis, Helicotylenchus microlobus, Helicotylenchus vulgaris, Merlinius brevidens, and Pratylenchoides alkani. With the exception of H. microlobus and M. brevidens, reports of these plant-parasitic nematode species constitute new records for Greece. Bitylenchus hispaniensis is also reported for first time in a country outside of Spain, where it was originally described. Pratylenchoides alkani is herein reported for the second time in the Mediterranean area and for the first time in association with olive. Two further populations of H. microlobus and H. vulgaris, from walnut and goji berry from Greece, were identified. Molecular data for all of these nematode species are provided, resulting in the first integrative identification of these Greek populations. [ABSTRACT FROM AUTHOR]

Longidorids are economically important plant-parasitic nematodes because several species are virus vectors. Populations of Paralongidorus sali and Longidorus jonesi, isolated from woody perennials of Hangzhou, Zhejiang, China, were characterized molecularly and morphologically. The morphometric data of the Chinese populations of both species were compared with other populations. The present study provided a first record of the occurrence of Paralongidorus in China coupled with description of the first-stage juvenile and male of L. jonesi. Phylogenetic analysis based on 18S and D2-D3 expansion segments of 28S gene indicated that L. jonesi clustered with L. jonesi reported from Japan and P. sali grouped with P. bikanerensis from Iran. Considering the pathological and economic importance of this group of nematodes, the study emphasized the need of updated descriptions from accurately identified specimens, isolation of sufficient material for examination, and molecular and phylogenetic analysis for a better understanding and diagnostics of Longidorid nematodes. [ABSTRACT FROM AUTHOR]

Aim: Haemonchus contortus is the most pathogenic nematode infesting the digestive tract of goats and sheep worldwide leading to a tremendous loss in a variety of routes. Economic losses due to haemonchosis in subtropic and tropic areas are usually caused by poor weight gain, minimized growth, loss of production, and mortality. The prevalence of haemonchosis in Indonesia is 89.4% in goat, and annual loss achieved 1 million US dollars. This study evaluated in vitro effects of Gigantochloa apus crude aqueous extract as an anthelmintic on H. contortus morphology and morphometry. Materials and Methods: Bligon goats which are naturally infected were collected from slaughtered goat from local slaughterhouses, namely Besi Sleman. Bligon goat's abomasum part was carefully examined and transported to the Parasitology Laboratory, University of Gadjah Mada, Yogyakarta. H. contortus was obtained from 4 to 6-month-old female goat from slaughterhouses in Yogyakarta area. H. contortus was collected from abomasum and put into a Petri dish containing 0.62% water saline. The number of H. contortus used for each concentration is 25. H. contortus was soaked in each concentration for 4 h. The figure of the parasites or parts of parasites was captured using camera Lucida, and they were measured using both objective micrometer and objective ocular micrometer. All the capturing processes were done with the help of Olympus Digital Camera under Olympus CX21 microscopic. Parasite morphology was identified in morphological and morphometric characters. Results: Morphology of H. contortus revealed the cervical papillae bulge appears unclear shape and anterior end is more tapered. Vulvar flab control is not tapered, but vulvar flab which gets aware of G. apus crude aqueous extract looks more pointed. The gubernaculum appears irregular compared to gubernaculum control which tends to be more compact, and the posterior end form appears irregular more than posterior end control. Morphometry study of H. contortus indicates that it has a significant difference for body length, body width, cervical papillae, and spicule length in the male. Conclusion: G. apus crude aqueous extract activity revealed morphology change such as cervical papillae, vulvar flab, gubernaculum, posterior end, and reduced morphometry measurement of H. contortus adult worms, notably in body length, body width, cervical papillae width, gubernaculum, and spicule length in males and body length, body width, cervical papillae width, and vulva length in females. [ABSTRACT FROM AUTHOR]

Helicotylenchus microlobus is considered to be a junior synonym of H. pseudorobustus by several authors while others consider it as valid. To clarify the status of both species, 39 samples collected from various countries were subjected to statistical analyses that showed they could be grouped into six groups. Topotypes of H. pseudorobustus and H. microlobus belong to two different groups. However, samples in the other groups were morphologically intermediate between these two groups. Characters used in the past to uphold the validity of H. microlobus were variable and overlapping from group to group. The 28 samples studied are identified as H. pseudorobustus. Helicotylenchus microlobus, H. bradys and H. phalerus are confirmed as junior synonyms of H. pseudorobustus. There was no complete congruence between the morphological groups and molecular groups proposed by other authors. For these, two MOTU (Molecular Operational Taxonomic Unit) are accepted within H. pseudorobustus. [ABSTRACT FROM AUTHOR]

Paurodontella gilanica n. sp. is described and illustrated based on morphological, morphometric and molecular characters. The new species is characterised by its small body size, four lines in the lateral field, weak stylet with minute asymmetrical knobs, female reproductive system lacking a diverticulum but with small post-vulval uterine sac, elongate conoid tail with pointed, sometimes filiform, tip, males common with small spicules and cloacal bursa not reaching tail tip. Morphological differences between the new species and seven known species of the genus, namely P. asymmetrica, P. auriculata, P. balochistanica, P. minuta, P. myceliophaga, P. parapitica and P. persica, are discussed. The new species is also compared with four known species of Paurodontus having four lines in the lateral field. Using a 1123 nt long partial 18S rDNA sequence of the new species to reconstruct the phylogenetic relationships revealed that it formed a clade with members of the Sphaerulariidae and Paurodontidae. Using a 746 nt long partial sequence of the 28S rDNA D2-D3 segment revealed that P. gilanica n. sp. formed a clade with Abursanema iranicum in both Bayesian inference (BI) and maximum likelihood (ML) analyses with 0.99 Bayesian posterior probability (BPP) and 89% bootstrap support value (BS). The morphological affinities of Paurodontella and Paurodontus are discussed. [ABSTRACT FROM AUTHOR]

The genus Sakia is recorded from Iran for the first time and Sakia arboris n. sp., recovered from two geographical points in northern Iran, is described. The new species is characterised by its smooth cuticle under light microscopy (LM), absence of lateral fields, head continuous with body contour, flattened lip region, 9.3 (9.0-10.0) µm long stylet, vulva at 60.2 (59.3-61.3)%, bilobed spermatheca, 117 (102-128) µm long tail, and 14.3 (14-15) µm long spicules. By lacking lateral fields, the new species comes close to three known species of the genus, namely: S. alii, S. castori and S. indica. Molecular phylogenetic analyses using sequences of the near full-length fragment of the small subunit of ribosomal DNA (18S rDNA) and the D2-D3 expansion segments of the large subunit ribosomal DNA (28S rDNA) were performed using Bayesian inference (BI) and maximum likelihood (ML) methods. In the reconstructed Bayesian tree using the 18S rDNA sequence of the type population, the new species occupied a position in a clade including two isolates of Sakia sp. and some species of Lelenchus, with maximal BPP and high ML BS values (1.00/99%). In the reconstructed 28S rDNA phylogenetic tree, two newly sequenced isolates of S. arboris n. sp. formed a well-supported clade with Lelenchus spp. [ABSTRACT FROM AUTHOR]

A population of Macrolaimus arboreus was collected from the rhizosphere of pine in Iran. This population of M. arboreus is characterised by the body length, 800-1010 µm in females, lip region with six seta-like papillae directed anteriad, stoma nearly as long as wide (9-11 × 7 µm), with cheilostom slightly longer than gymnostom and cheilorhabdia and gymnorhabdia well-developed, pharyngeal corpus 1.8-2.0 times the isthmus length, with slightly swollen metacorpus, excretory pore located at isthmus level, female reproductive system monodelphic-prodelphic reflexed with short post-vulval uterine sac, female tail conical (57-67 µm, c = 13.7-15.0, c' = 3.5-3.8), ending in an acute tip which is weakly curved dorsad, and phasmids at 54-60% of tail length. Measurements and illustrations, including SEM, are provided. [ABSTRACT FROM AUTHOR]

A reverse taxonomic approach for characterisation of several populations of an aphelenchid nematode recovered from declined oak trees in the Zagros forests, Ilam, western Iran, revealed that their 28S rDNA D2-D3 sequences matched two available sequences of the same genomic fragment belonging to two species, Laimaphelenchus belgradiensis and L. hyrcanus. Further morphological studies yielded new morphological traits that had been overlooked in their original descriptions, and a new hypothesis helping to disentangle these taxa, which have the same 28S sequences and the same phylogenetic placement, is proposed. In a similar fashion, the taxonomic status of some other species of the genus having a similar morphology or similar genomic sequences are reviewed. The possibility of proposing new synonyms was evaluated and tentative reasons for the new habitat of the recovered populations of Laimaphelenchus from the Zagros forests discussed. [ABSTRACT FROM AUTHOR]

Sheathoid nematodes of the genus Hemicriconemoides are migratory root-ectoparasites of many crops but damage is documented for only a few species. Hemicriconemoides paracamelliae sp. n., isolated in Hangzhou, Zhejiang, China, from the rhizosphere of Cinninghamia lanceolata, is described together with H. kanayaensis and H. parataiwanensis. These three species are characterised morphologically and molecularly with important morphological details elucidated by SEM photographs. The new species can be characterised by the en face view having a dorsoventrally orientated oral disc with slit-like opening, and the labial plate being composed of two lateral semi-globular shaped projections on the lateral sides of the oral disc. This new species has the first lip annulus expanded and slightly wider than the second, stylet 83 (80-85) µm long, excretory pore located 5-6 annuli posterior to the base of the pharyngeal bulb, vulva slit-like, vulval flaps absent, spermatheca rounded to oblong-shaped, and anus located 5-8 annuli posterior to vulva. The tail is elongated, conoid, with the terminal annuli curving dorsally or ventrally to form a finely rounded tip. The study provides the first record of H. kanayaensis from mainland China, a new host association of H. parataiwanensis, and molecular sequencing data of the 18S, 28S D2-D3 and ITS sequences. [ABSTRACT FROM AUTHOR]

The placement of the rare deep-sea nematode order Rhaptothyreida remains unclear due to the unique morphology of this group, an unknown life cycle with morphologically distinct juvenile stages which may or may not be parasitic, and lack of molecular sequences. Here, we investigate the phylogenetic placement and status of the Rhaptothyreida based on SSU and D2-D3 of LSU rDNA sequences of Rhaptothyerus typicus specimens obtained from the continental slope of New Zealand. Molecular sequences of three adults and a late stage juvenile were identical, confirming that they belong to the same species despite pronounced morphological differences. We observed the presence of the rare nucleotide transition A → G and transversion G → Y in the loops of Hairpin 35 and 48 regions, which is consistent with the placement of R. typicus within the order Enoplida. Rhaptothyreus typicus was consistently recovered as a long branch clade in SSU and D2-D3 of LSU analyses, which can have a destabilising effect on tree topology. After Gblocks were used to remove sites of questionable alignment, R. typicus was placed in a clade comprising Trissonchulus , Dolicholaimus and Ironus sequences (family Ironidae, order Enoplida) in both Bayesian and Maximum Likelihood SSU topologies. Depending on which alignment algorithm was used, analyses of LSU sequences focusing on enoplid taxa either suggested a relationship between R. typicus and Halalaimus (family Oxystominidae) or did not identify any clear relationships. Overall, our results provide strong evidence for placing R. typicus and the family Rhaptothyreidae within the order Enoplida, although further work is required to clarify relationships between rhaptothyreids and other enoplid taxa. A parasitic lifestyle could explain the unique morphology of this group, their highly divergent SSU and LSU rDNA molecular sequences, and the marked morphological differences between late juveniles and adults. Further molecular investigations targeting both free-living and parasitic early juvenile life stages in potential deep-sea hosts are needed to better understand the evolution of this unusual nematode taxon. [ABSTRACT FROM AUTHOR]

The phylogenetic position of Paramicrolaimidae Lorenzen, 1981, a rare group of marine free-living nematodes, has been the subject of debate due to the unique morphology of the buccal cavity, an unusual combination of other morphological traits, and lack of molecular sequences. Here, Paramicrolaimus hohonucola sp. nov. is described from the continental slope of New Zealand, and the position of the family Paramicrolaimidae is investigated based on analyses of the small subunit (SSU) and D2–D3 region of large subunit (LSU) rDNA genes. This is the first record of Paramicrolaimidae from the Southwest Pacific, and the deepest record of the family to date (347–1514 m depth). Observations using scanning electron microscopy revealed the presence of a transverse mouth opening formed by the fusion of the two ventrosublateral lip lobes and enlarged dorsal lip lobe, resulting in partial dorsoventral symmetry, which is an unusual feature within the phylum. Phylogenetic analyses suggest a close relationship between the Paramicrolaimidae and the family Selachinematidae Cobb, 1915 (order Chromadorida Chitwood, 1933). The Paramicrolaimidae lack cuticle punctations, a key morphological trait of all families currently classified within the Chromadorida; however, in the absence of any clear morphological affinities with other chromadorean orders, we propose that Paramicrolaimidae be placed within Chromadorida based on evidence for a close relationship with Selachinematidae as shown by SSU and LSU phylogenies. Our SSU phylogeny supports the results of previously published analyses showing a close relationship between Molgolaimus Ditlevsen, 1921 and the Microlaimidae Micoletzky, 1922. We therefore propose that Molgolaimus be removed from Desmodoroidea where it is currently classified and instead placed within Microlaimoidea. We also propose that the family Molgolaimidae Jensen, 1978 be reinstated and moved to accommodate Molgolaimus within Microlaimoidea. As in previous SSU phylogenies, our analyses provide no evidence for a close relationship between Desmodoroidea and Microlaimoidea, which currently comprise Desmodorida. Based on this molecular evidence, the clear morphological differences between Microlaimoidea and the closely related Chromadorida, and the lack of a synapomorphy linking Desmodoroidea and Microlaimoidea, we propose the order Microlaimida ord. nov. to accommodate the superfamily Microlaimoidea. [ABSTRACT FROM AUTHOR]