Description of Longidorella (Saevadorella) caspica n. sp. (Dorylaimida: Nordiidae) from north Iran.

This contribution provides the morphological and molecular identification of a new species of the genus Longidorella (Saevadorella). L. (S.) caspica n. sp., was recovered from the rhizospheric soil of grasses in Mazandaran province in the seashore of the Caspian Sea. It is characterized by females with a length of 788 to 874 µm and a cephalic region with prominent papillae; and separated from the rest of the body by a remarkable constriction, an odontostyle of 32 to 33 µm, vulva at 52.5 to 59.0%, and a tail of 33 to 38 µm with a rounded tip. Males have 32 to 35 µm long spicules of dorylaimoid form and five to seven ventral supplements ending at 48 to 55 µm distance from cloacal pair. The new species was morphologically compared with seven nominal species viz. L. (S.) arenicola, L. (S.) cuspidata, L. (S.) magna, L. (S.) perplexa, L. (S.) saadi, L. (S.) saevae, and L. (S.) tharensis. It was further compared with similar species under the subgenus Longidorella (Enchodorella) viz. L. (E.) deliblatica and L. (E.) murithi. Besides morphological studies, molecular phylogenetic studies using partial sequences of D2 to D3 expansion fragments of 28S rDNA were performed for the new species and its phylogenetic relationships with other species and genera were discussed.

New Distribution and Molecular Diversity of the Reniform Nematode Rotylenchulus macrosoma (Nematoda: Rotylenchulinae) in Europe.

Reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant species roots and occur largely in regions with temperate, subtropical, and tropical climates. In this study, we provide new records of the nematode Rotylenchulus macrosoma in eight European countries (Czech Republic, France, Germany, Hungary, Italy, Romania, Serbia, and Portugal), in addition to the six Mediterranean countries (Greece, Israel, Jordan, Spain, Syria, and Turkey) where the nematode was previously reported. Four new host species (corn, pea, wheat, and an almond-peach hybrid rootstock) are added to the recorded host species (bean, chickpea, hazelnut, peanut, soybean, and wild and cultivated olive). Molecular analyses based on the cytochrome c oxidase subunit coxI and D2-D3 segments of 28S RNA markers showed high diversity and pronounced genetic structure among populations of Rotylenchulus macrosoma. However, the complexity of phylogeographic patterns in plant-parasitic nematodes may be related to the intrinsic heterogeneity in the distribution of soil organisms, a rare occurrence of a species, or the potential human impact associated with agricultural practices.

New and known species of the genus Pungentus Thorne & Swanger, 1936 (Dorylaimida, Nordiidae) from Iran.

This contribution provides morphological and molecular data for one new and one known species of the genus Pungentus. The first species, P. azarbaijanensis n. sp., was recovered from the rhizospheric soil of grasses, collected in West Azarbaijan province, Iran, and was characterized by 2082-2365 µm long females having an angular lip region separated from the rest of the body by a constriction, 33-35 µm long odontostyle, vulva at 43.5-51.0%, 27.0-29.5 µm long rounded-conoid tail, and males unknown. It was compared morphologically with five species: P. angulosus, P. crassus, P. marietani, P. parapungens and P. pungens, which have didelphic-amphidelphic female reproductive system, body longer than 1.5 mm, and odontostyle longer than 20 µm. The second species, P. engadinensis, was recovered in three different regions of Iran (Mazandaran, Semnan and East Azarbaijan provinces). It was compared morphologically with some other populations reported all over the world. Besides morphological studies, molecular phylogenetic studies using partial sequences of 28S rDNA D2-D3 fragments were performed, and the phylogenetic relations of the two Iranian populations with other species and genera were discussed.

Description of a new species of the genus Anguillonema Fuchs, 1938 (Nematoda: Sphaerularioidea) with an identification key to the species.

Anguillonema iranicum n. sp. is described and illustrated as the second species of this genus from Iran, based on morphological, morphometric and molecular characteristics. It is identified by a short, thin body, a continuous lip region, six lines on the lateral field, a short, thin stylet, a posteriorly located pharyngo-intestinal junction to excretory pore, the presence of a post-vulval uterine sac, vulval position at 89% (87.4-89.9%) of body length, an elongate conoid tail with a rounded to pointed tip and not dorsally bent, and common functional males with short spicules and lacking a bursa. Morphological differences between the new species and the three known species of the genus, namely A. amolensis, A. crenati and A. poligraphi, are discussed. Molecular phylogenetic studies of the new species using partial 18S rDNA sequence revealed that it formed a sister clade with three species of Howardula, one species of Anguillonema and one unidentified isolate. In phylogenetic analyses using partial sequences of 28S rDNA D2-D3 segment, the new species formed a clade with two isolates of Parasitylenchus. A key to identification of Anguillonema species is also presented.

Morphological and Molecular Characterization of Labrys filiformis n. sp. (Rhabditida: Tylenchidae) from Iran.

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 .

Molecular and morphological characterization of Paurodontoides siddiqii n. sp. (Nematoda: Hexatylina, Sphaerulariidae) associated with bark samples of Pinus eldarica from western Iran.

A new species of Paurodontoides, P. siddiqii n. sp., is described and illustrated based on its morphological, morphometric, and molecular characters. The new species is characterized by a female 550-729 µm long, lip region continuous with body contour, stylet length 7.0-8.0 µm long or c. 1.0-1.2 times the lip region diameter, lateral fields with four smooth incisures, excretory pore at 85-125 µm from anterior end located at the base of the pharyngeal bulb or posterior to it, basal pharyngeal bulb with a short posterior extension projecting into the intestine, monodelphic-prodelphic reproductive system with prominent 19-22 µm long post-uterine sac, and elongate conoid tail with a filiform terminus. The new species is compared with two known species of the genus. It differs from the type species of the genus, P. linfordi, by having slightly shorter stylet, lateral field with smooth incisures, different position of the excretory pore, and absence of male. Compared to P. latus, the new species has a shorter body, shorter stylet, different position of the excretory pore, female tail shape and absence of male. The new species was also compared with close species of the genus Paurodontus because of lateral field marked with four lines, asymmetrical stylet knobs and absence of male. Molecular phylogenetic studies of the new species using partial sequences of 18S rDNA revealed that it forms a clade with a species of the genus Ficotylus. In phylogenetic analyses using partial sequences of the 28S rDNA D2-D3 domain, the new species formed a monophyletic group with a species of the genus Veleshkinema and Sphaerularia spp. (Sphaerulariinae).

First record of the genus Parasitorhabditis Fuchs, 1937 (Rhabditida, Nematoda) from Iran with notes on morphological and molecular characters of the Iranian population of P. obtusa (Fuchs, 1915) Chitwood & Chitwood, 1950.

Parasitorhabditis obtusa is reported from Iran for the first time. The studied population is characterised with its morphological and molecular data. Morphological characters of the recovered population is in agreement with the currently available data of the species. In molecular phylogenetic studies using partial sequences of 28S rDNA D2/D3 fragment, the species formed a clade with two other isolates of the species with maximal Bayesian posterior probability (1.00) and maximum likelihood bootstrap values (100). The species was in association with bark samples of dead coniferous trees having galleries of bark beetles. It was also recovered from inside of the body of the Mediterranean pine beetle, Orthotomicus erosus, representing a new insect host for this nematode species.

Description of Enchodorus yeatsi n. sp. (Dorylaimida, Nordiidae) from Southern Iran and Its Molecular Phylogenetic Study.

Enchodorus yeatsi n. sp., a new species of the rare genus Enchodorus is described and illustrated based on its morphological and molecular characters. It was recovered from southern Iran. Females of the new species are characterized by having 1,511.3- to 1,792.5-µm long slender body, angular lip region having prominent papillae, 12- to 13-µm long odontostyle, double guiding ring, simple rod-like odontophore, didelphic-amphidelphic reproductive system, and 102- to 160-µm long elongate-conoid tail with rounded tip. Males of the new species are abundant and functional, characterized by 1,484- to 1,576-µm long body, 40- to 43-µm long spicules, 5 to 6 ventromedian supplements, and ventrally bent elongate conical tail. Compared to the type species, Enchodorus dolichurus, the new species has differences in its tail morphology and V value. These morphological differences and the separation of two species was further supported with basic differences in sequences of 28S rDNA D2/D3 and internal transcribed spacer 1 (ITS1) fragments. Compared to Enchodorus neodolichurus, it has basic differences in tail characters and spicule lengths. Molecular phylogenetic studies using partial sequences of 28S rDNA D2/D3 fragment of the new species and available sequences of Nordiidae members and several other dorylaim species/genera, revealed E. yeatsi n. sp. and E. dolichurus forming a clade with 0.81 Bayesian posterior probability (BPP). This clade forms a sister clade to the clade of Heterodorus sp. and Rhyssocolpus vinciguerrae, again with 0.81 BPP. In ITS1 tree, reconstructed using few available sequences, the new species and E. dolichurus formed a clade with 0.98 BPP.

A metagenetic approach for revealing community structure of marine planktonic copepods.

Marine planktonic copepods are an ecologically important group with high species richness and abundance. Here, we propose a new metagenetic approach for revealing the community structure of marine planktonic copepods using 454 pyrosequencing of nuclear large subunit ribosomal DNA. We determined an appropriate similarity threshold for clustering pyrosequencing data into molecular operational taxonomic units (MOTUs) using an artificial community containing 33 morphologically identified species. The 99% similarity threshold had high species-level resolution for MOTU clustering but overestimated species richness. The artificial community was appropriately clustered into MOTUs at 97% similarity, with little inflation in MOTU numbers and with relatively high species-level resolution. The number of sequence reads of each MOTU was correlated with dry weight of that taxon, suggesting that sequence reads could be used as a proxy for biomass. Next, we applied the method to field-collected samples, and the results corresponded reasonably well with morphological analysis of these communities. Numbers of MOTUs were well correlated with species richness at 97% similarity, and large numbers of sequence reads were generally observed in MOTUs derived from species with large biomass. Further, MOTUs were successfully classified into taxonomic groups at the family level at 97% similarity; similar patterns of species richness and biomass were revealed within families with metagenetic and morphological analyses. At the 99% similarity threshold, MOTUs with high proportions of sequence reads were identified as biomass-dominant species in each field-collected sample. The metagenetic approach reported here can be an effective tool for rapid and comprehensive assessment of copepod community structure.