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Summary: Stegelletina salinaria is redescribed from Spain and South Africa. Spanish material was collected in sandy soil from the type locality and a nearby area, while one population collected in compost was examined from South Africa. The species is characterised by its small size (0.27-0.41 mm), lateral field with three incisures, lip region with three pairs of dentate lips bearing four tines each, primary axils bearing a large guarding process, secondary axils lacking guarding processes, nerve ring and secretory-excretory pore at isthmus level, spermatheca and post-vulval uterine sac poorly developed, female tail conoid with rounded hyaline terminus and males unknown. The description, light micrographs and scanning electron microscope images, illustrations and molecular analyses are provided. 18S and 28S rDNA sequence analyses show that the isolates of S. salinaria from Spain and South Africa are closely related to each other and to other species of Stegelletina , while also indicating a close relationship with some species of Nothacrobeles , Scottnema and Stegelleta (28S tree) and Zeldia (18S tree). [ABSTRACT FROM AUTHOR]

Aphelenchoides stellatus n. sp. is described and figured. The new species was isolated from packaging wood from Japan imported to Ningbo harbour, China. The new species has a body length of 485-533 μm (males) and 547-699 μm (females). The cuticle is weakly annulated and there are four lines in the lateral field. The stylet is 9-11 μm long and has small basal swellings. The excretory pore is located posterior to the nerve ring. Spicules smoothly curved, rose-thorn shaped. Apex and rostrum round, only slightly offset, dorsal limb 19-21 μm long. Male tail bearing six (2 + 2 + 2) caudal papillae. The female spermatheca is axial and oblong with round sperm present in multiple rows. Both male and female tail pegs have 3-4 processes, appearing star-like under SEM. The new species belongs to the Group 3 category of Aphelenchoides species. Phylogenetic analyses based on full length ITS and 28S D2/D3 region of rDNA confirmed its morphological status as a new species. [ABSTRACT FROM AUTHOR]

Pin nematodes of the genus Paratylenchus are widely distributed across the world and associated with many plant species. Morphological identification of Paratylenchus species is a difficult task because it relies on many characters with a wide range of intraspecific variation. In this study we provide morphological and molecular characterisation of several pin nematodes: Paratylenchus aquaticus, P. dianthus, P. hamatus, P. nanus and P. straeleni, collected in different states of the USA and South Africa. Paratylenchus aquaticus is reported from South Africa and Hawaii and P. nanus is found from South Africa for the first time. Morphological descriptions, morphometries, light and scanning electron microscopic photos and drawings are given for these species. Molecular characterisation of nematodes using the D2-D3 of 28S rRNA and ITS rRNA gene sequence revealed that samples morphologically identified as P. aquaticus, P. hamatus and P. nanus indeed represent species complexes containing several species. Sequences of the rRNA genes are also provided for several unidentified Paratylenchus. Phylogenetic relationships within the genus Paratylenchus are given as inferred from the analyses of the D2-D3 of 28S rRNA and ITS rRNA gene sequences. We present here the most complete phylogenetic analysis of the genus. [ABSTRACT FROM AUTHOR]

The morphology of Meloidogyne chitwoodi is relatively poorly characterised. In a recent study, morphological variation in adult females of M. chitwoodi was analysed. However, comparable data are lacking for adult males and second-stage juveniles (J2). Therefore, our studies of four M. chitwoodi isolates from the western USA, representing all currently known races and pathotypes, were designed to characterise intraspecific morphological variability in J2 and males and to compare it to variability found in adult females. Multivariate analysis of variance indicated statistically significant variation among isolates for both J2 and males. Moreover, for adult males, canonical discriminant analysis grouped races with their respective pathotypes. In addition, we analysed two morphological features that were previously uncharacterised for M. chitwoodi, i.e., stylet knob width and distance from secretory-excretory pore to anterior end. Both of these characters may be useful in distinguishing M. chitwoodi from closely related species. SEM clearly showed the presence of areolations along the bodies of J2, thereby separating M. chitwoodi from M. fallax and M. minor. In summary, this study indicates that M. chitwoodi J2 and adult males show substantially more intraspecific morphological variability than previously known. Consequences for diagnostics are discussed. [ABSTRACT FROM AUTHOR]

Examination of perianal folds of stinkpot turtles, Sternotherus odoratus, from Virginia, USA, revealed several monhysterid nematodes. The general morphological characteristics of this population, such as circular amphids, unstriated cuticle under light microscope, single outstretched ovary, single testis, caudal glands, terminal spinneret and the absence of an apophysis on the gubernaculum, with the exception of the position of the gonad in relation to the intestine, shows the affinity of this population to the Monhysteridae. Microscopic observations of the inner stoma show three (one dorsal and two ventro-sublateral) buccal wall extensions towards the lumen and numerous (ca 50) distinct denticles on its wall. Because this stoma structure is a morphological novelty within the Monhysterida and this is the first monhysterid group associated with perianal folds of turtles, we propose to establish Testudinema n. gen. within the Monhysteridae to accommodate this morphologically distinct population. We provide a detailed comparison with known monhysterid genera including those that possess a cup-shaped stoma, stoma with denticles or those genera reported to be commensals (Gammarinema, Monhystrium, Tripylium, Odontobius). Stinkpot turtles feed on benthic fauna and may acquire these commensals when the sediment is disturbed. The denticles and structure of the buccal cavity could be morphological adaptations for transition to ecto-parasitism. [ABSTRACT FROM AUTHOR]

Descriptions of eight new and three known species of Tarvaia are given. Tarvaia pacifica sp. n. has cephalic capsule reaching posterior part of short amphids, amphidial shield without ornamentation, straight vagina with pars refringens vaginae, slightly asymmetrical spicules, gubernaculum with two dorsal apophyses, precloacal ridge present; T. algicola sp. n. has cephalic capsule with unevenly thickened walls reaching posterior part of short amphids, amphidial shield without ornamentation, straight vagina, apophyses absent, precloacal ridge present; T. carolinensis sp. n. has cephalic capsule reaching posterior part of short amphids, amphidial shield with ornamentation, sigmoid vagina, gubernaculum with a dorsal apophysis; T. longispiculata sp. n. has elongated cephalic capsule reaching posterior part of elongate amphids, amphidial shield without ornamentation, sigmoid vagina, unusually long spicules, gubernaculum with dorsal apophysis, precloacal ridge present; T. inaequalis sp. n. has short cephalic capsule reaching anterior third of elongate amphids, amphidial shield with ornamentation, straight vagina, strongly anisometric spicules, gubernaculum with caudal apophysis, precloacal ridge present; T. sakhalinensis sp. n. has short cephalic capsule reaching middle of short amphids, amphidial shield with distinct pores, symmetrical spicules, apophyses absent; T. tchesunovi sp. n. has cephalic capsule with unevenly thickened walls reaching posterior part of short amphids, amphidial shield without ornamentation, symmetrical spicules, apophyses absent; and T. ricordensis sp. n. has cephalic capsule reaching posterior part of short amphids, amphidial shield without ornamentation, straight vagina, symmetrical spicules, gubernaculum with dorsal apophyses. Updated descriptions of T. donsi, T. cladara and T. gerlachi are provided. Phylogenese analysis based on 18S rDNA suggests a close relationship between Tarvaia and Desmoscolecida. [ABSTRACT FROM AUTHOR]