Description of Aporcella daklakensis sp. n. (Nematoda: Dorylaimida: Aporcelaimidae), associated with coffee plantations in Central Highland of Vietnam.

A new species of the genus Aporcella, collected in replanted coffee orchards in Central Highland of Vietnam, is described and illustrated. Aporcella daklakensis sp. n. is characterized by its 1.63-1.98 mm long body, lip region offset by weak constriction and 14-15 µm broad, odontostyle 13-15 µm long or equal to lip region diameter, neck 400-565 µm long, pharyngeal expansion 205-335 µm long and occupying 51-60% of the total neck length, female genital system diovarian with very poorly developed genital tract and transverse vulva (V = 53-59), tail conical with rounded terminus (31-39 µm, c = 43-57, c' = 1.0-1.4), visibly subdigitate and bearing cuticular irregularities at its ventral side, and male absent. The new species is compared with its closest Aporcella representatives.

Morphological and Molecular Characterization of Talanema eshtiaghii sp. n. (Dorylaimida, Qudsianematidae) from Iran.

A new species of the genus Talanema, recovered from the northwest of Iran, was described based on morphological, morphometric, and molecular data. Talanema eshtiaghii sp. n. was characterized by its 1.45-1.68 mm long body, lip region offset by constriction and 13-15 µm wide, odontostyle 15-18 µm long, double guiding ring, neck 312-362 µm long, pharyngeal expansion occupying 41-43% of the total neck length, uterus tripartite, and 111-189 µm long or 2.1-3.2 body diameters, vulva transverse (V = 55-58), tail similar in both sexes, conical with a dorsal concavity (30-44 µm, c = 33-56, c' = 1.0-1.6), spicules 49-56 µm long, and 14-18 shortly spaced ventromedian supplements in front of the level of the anterior end of spicules, with distinct hiatus. It was compared to four closely similar species, with emphasis on the most relevant traits to distinguish them. Molecular phylogenetic studies using partial sequence of the 28S rDNA (D2-D3 segment) revealed that the new species forms a clade with other currently sequenced representatives of Talanema, tentatively supporting the monophyly of this genus.

Description of Crassolabium unicum sp. n. (Nematoda: Dorylaimida: Qudsianematidae) from Vietnam.

Crassolabium unicum sp. n., collected from a natural habitat in Vietnam, is described and illustrated. The new species is characterized by its 0.770.94 mm long body, three-layered cuticle, lip region offset by depression and 1213.5 µm broad, odontostyle 13.515 µm long with wide aperture occupying 3646% of its length, neck 235260 µm long, pharyngeal expansion 117131 µm long or occupying 4752% of total neck length, anterior part of intestine presenting very distinct folds, female genital system didelphic-amphidelphic, uterus simple and 2843 µm or 0.70.9 body diameters, vulva transverse (V = 4552), prerectum bearing a blind postrectal sac, caudal region short and rounded (2125 µm, c = 4561, c' = 0.60.8) with two (dorsal and ventral) lacunae between outer and intermediate cuticle layers, and male unknown. It is compared with the similar representatives of the genus.

New insights into the identity of Discolaimium dubium Das, Khan and Loof, 1969 (Dorylaimida) as derived from its morphological and molecular characterization, with the proposal of its transference to Aporcella Andrássy, 2002.

Three Iranian populations of Discolaimium dubium are studied, including their morphological and morphometric characterization, molecular analysis (LSU-rDNA) and the description of the male for the first time. For comparative purposes, this species is distinguished by its 1.10 to 1.40 mm long body, lip region offset by constriction and 8 to 10 µm wide, odontostyle 7.5 to 10.5 µm long with aperture occupying 59 to 76% of total length, neck 300 to 362 µm, pharyngeal expansion 127 to 181 µm long or 44 to 46% of the total neck length, uterus simple and 38 to 53 µm or 1.2 to 1.5 times the body diameter long, V = 52 to 58, tail conical (32-38 µm, c = 32-43, c' = 1.6-2.0) with rounded tip and a hyaline portion occupying 14 to 15% of tail length, spicules 30 to 32 µm long, and two or three widely space ventromedian supplements with hiatus. Both morphological and molecular data support its belonging to the genus Aporcella, whose monophyly is confirmed and to which the species is formally transferred as A. dubia (Das et al., 1969) comb. n.

On the identity of Eucephalobus oxyuroides (de Man, 1876) Steiner, 1936 (Rhabditida, Cephalobidae), with an updated taxonomy of the genus and notes about its phylogeny.

The identity of Eucephalobus oxyuroides is discussed after studying two Iberian populations that fit the original description of the species. A new characterization is consequently provided as follows: 0.49 to 0.70 mm long body, lip region continuous with the adjoining body and bearing short probolae prongs, neck 132 to 158 µm long, spermatheca 23 to 47 µm long or 1.0 to 1.8 times the corresponding body diameter, post-vulval uterine sac 40 to 54 µm long or 2.0 to 2.5 times as long as the body diameter, V = 58 to 64, female tail conical elongate with very acute terminus (60-79 µm, c = 7.1-10.0, c' = 4.9-5.8), male tail conical (36-49 µm, c =10.9-14.3, c' = 2.4-3.4) with an elongate acute mucro, and spicules 21 to 22 µm long. Previous records of the species are revised. An emended diagnosis of the genus is proposed, and its taxonomy is updated with a list of species, key to their identification and illustrations. The evolutionary relationships of Eucephalobus, as derived from the analyses of 18S and 28S rDNA fragments, reveals that it occupies a basal position within the subfamily Cephalobidae.The identity of Eucephalobus oxyuroides is discussed after studying two Iberian populations that fit the original description of the species. A new characterization is consequently provided as follows: 0.49 to 0.70 mm long body, lip region continuous with the adjoining body and bearing short probolae prongs, neck 132 to 158 µm long, spermatheca 23 to 47 µm long or 1.0 to 1.8 times the corresponding body diameter, post-vulval uterine sac 40 to 54 µm long or 2.0 to 2.5 times as long as the body diameter, V = 58 to 64, female tail conical elongate with very acute terminus (60-79 µm, c = 7.1-10.0, c' = 4.9-5.8), male tail conical (36-49 µm, c =10.9-14.3, c' = 2.4-3.4) with an elongate acute mucro, and spicules 21 to 22 µm long. Previous records of the species are revised. An emended diagnosis of the genus is proposed, and its taxonomy is updated with a list of species, key to their identification and illustrations. The evolutionary relationships of Eucephalobus, as derived from the analyses of 18S and 28S rDNA fragments, reveals that it occupies a basal position within the subfamily Cephalobidae.

Morphological and molecular characterization of Pungentus sufiyanensis n. sp. and additional data on P. engadinensis (Altherr, 1950) Altherr, 1952 (Dorylaimida: Nordiidae) from northwest of Iran.

Two species of the genus Pungentus, one new and one known, collected in natural vegetation and cultivated soils in northwest of Iran, are studied. Pungentus sufiyanensis n. sp. is characterized by its 1.22 to 1.57 mm long body, offset lip region by a constriction and 7 to 9 µm broad, 18 to 21 µm long odontostyle, 304 to 348 µm long neck, 133 to 161 µm long esophageal expansion, mono-opisthodelphic female genital system without anterior uterine sac, slightly backward directed vagina, absence of pars refringens vaginae, V = 47-54, rounded-conoid caudal region (17.5-23 µm, c = 65-84, c´ = 0.7-1) with saccate bodies, and the absence of male. Molecular analysis, based on D2-D3 expansion segments of the 28S rDNA (LSU), confirms the monophyly of the family Nordiidae and suggests the monophyly of the genus Pungentus, with the new species forming a clade with other Iranian species. New data are presented for six Iranian populations of P. engadinensis, and an updated key for the identification of Pungentus species is also provided.Two species of the genus Pungentus, one new and one known, collected in natural vegetation and cultivated soils in northwest of Iran, are studied. Pungentus sufiyanensis n. sp. is characterized by its 1.22 to 1.57 mm long body, offset lip region by a constriction and 7 to 9 µm broad, 18 to 21 µm long odontostyle, 304 to 348 µm long neck, 133 to 161 µm long esophageal expansion, mono-opisthodelphic female genital system without anterior uterine sac, slightly backward directed vagina, absence of pars refringens vaginae, V = 47−54, rounded-conoid caudal region (17.5­23 µm, c = 65­84, c´ = 0.7­1) with saccate bodies, and the absence of male. Molecular analysis, based on D2-D3 expansion segments of the 28S rDNA (LSU), confirms the monophyly of the family Nordiidae and suggests the monophyly of the genus Pungentus, with the new species forming a clade with other Iranian species. New data are presented for six Iranian populations of P. engadinensis, and an updated key for the identification of Pungentus species is also provided.

Morphological and molecular characterization of Epidorylaimus procerus sp. n. (Dorylaimida: Qudsianematidae) from Vietnam.

Epidorylaimus procerus sp. n., collected from a natural habitat in Vietnam, is described and illustrated. It is distinguishable by its 2.16 to 2.46-mm-long body, lip region offset by depression and 15 to 17-µm broad, odontostyle 32 to 35-µm long, neck 415 to 461-µm long, pharyngeal expansion occupying 47 to 52% of the total neck length, uterus 76 to 130-µm long or 1.0 to 1.5-body diameters, vulva transverse (V = 40-43), caudal region conical elongate (157-186 µm, c =12.1-14.4, c' = 4.4-5.5) with blister-like bodies, and hyaline portion occupying one-fourth its length, and males absent. Molecular analysis shows a close relationship of the new species and E. lugdunensis, supporting monophyly of the genus Epidorylaimus.

Description of Metarhabditis giennensis sp. n. (Nematoda, Rhabditida, Rhabditidae) from decaying wood of a riverbank forest in the southern Iberian Peninsula.

A new species of the genus Metarhabditis, M. giennensis sp. n., collected from a riverbank poplar forest in the southern Iberian Peninsula, is described and illustrated, including SEM observations. The new species is characterized by its 1.01-1.16 mm long body in females and 0.77-0.98 in males, cuticle with very fine transverse striation, lip region 9-14 µm broad and consisting of six swollen rounded lips fused in pairs, stoma 14-25 µm long with tubular gymno-promesostegostom, pharynx with slightly swollen metacorpus and slender isthmus, nerve ring, excretory pore and deirids located at isthmus level, female reproductive system didelphic-amphidelphic, vulva equatorial (V = 49-50), female rectum length 1.2-1.7 times the anal body width, female tail conical-elongate with acute tip (123-199 µm, c = 5.8-8.2, c' = 8.2-11.1), male tail conical (34-56 µm, c = 15.5-25.7, c' = 2.4-3.5), bursa leptoderan, 32-41 µm long spicules with rounded and ventrally bent manubrium, and 17-20 µm long gubernaculum. An updated list of species of the genus and a key for their identification are also provided. [Zoobank URL: urn:lsid:zoobank.org:act:7EBAC9DB-A148-4A1A-97E5-3B796D0839BF].

Description of Tylencholaimus discus sp. n. (Nematoda, Dorylaimida, Tylencholaimidae) from Iran.

A new species of the genus Tylencholaimus, collected in natural areas of Iran, is described and illustrated, including SEM observations. Tylencholaimus discus sp. n. is characterized by its 0.65-0.76 mm long body, lip region offset by weak constriction and 7-7.5 µm broad with a conspicuous perioral disc, odontostyle 6-7 µm long, odontophore 9-10.5 µm long and visibly flanged rather than knobbed, neck 230-259 µm long with anterior region weakly muscular and basal expansion 98-125 µm long or occupying 42-49% of total neck length, female genital system mono-prodelphic, posterior branch reduced to a uterine sac 2-20 µm long or much shorter (0.1-0.6 times) than body diameter but very occasionally consisting of uterus, sphincter and a small terminal mass all together measuring 35-40 µm long, V = 65-74, tail short and rounded (13-17 µm, c = 41-57, c' = 0.6-0.8), and male unknown.

The genus Metaporcelaimus Lordello, 1965 (Nematoda, Dorylaimida, Aporcelaimidae) in Ukraine. Description of one new and one known species with granulate egg shell.

Two Metaporcelaimus species, one new and one known, are described from Ukraine. Metaporcelaimus petrophilus sp. n. is characterized by its 1.30-1.58 mm long body, lip region offset by deep constriction and 16-18 µm broad, odontostyle 15-17 µm long, neck 360-413 µm long, pharyngeal expansion occupying 47-54% of total neck length, uterus simple and 83-125 µm long or 1.6-2.7 times the corresponding body diameter, uterine eggs with granulate shell, V = 51-55%, tail conical (35-40 µm, c = 33-42, c' = 1.4-1.8 in females), spicules 43-50 µm long, and 9-13 spaced ventromedian supplements with hiatus. New data, including the first description of male specimens and SEM study, are provided for M. ovogranulosus, the Ukrainian populations of which are nearly identical to the type population from California.

Morphological and Molecular Characterization of Oscheius saproxylicus sp. n. (Rhabditida, Rhabditidae) From Decaying Wood in Spain, With New Insights into the Phylogeny of the Genus and a Revision of its Taxonomy.

A new species of the genus Oscheius, O. saproxylicus sp. n., collected in decaying wood obtained from an orchard in Southern Iberian Peninsula, is reported. A detailed description, including morphometrics, LM and SEM images, and molecular (18S and 28S rDNA genes) information is provided. The female is characterized by a moderately long body, lateral field with three longitudinal ridges, midbody vulva, and conical tail with acute tip. It was distinguished from its closest relative, O. dolichura, by a shorter tail and longer rectum. The male was not found. Morphological and molecular data support its belonging to Dolichura-group. Molecular analyses show that both Insectivorus and Dolichura groups are related to each other, being proposed as subgenera of the genus Oscheius as Oscheius and Dolichorhabditis. Finally, an updated taxonomy of the genus is presented, with generic and subgeneric diagnoses, list of species and a key to their identification.

Two new species of the genus Metaxonchium Coomans Nair, 1975 (Nematoda, Dorylaimida, Belondiridae) from Vietnam.

Two new species of the genus Metaxonchium are described from natural habitats of Vietnam. Metaxonchium bonkowskii sp. n. is characterized by its 1.69-2.23 mm long body, lip region offset by weak constriction and 9.5-10.5 µm broad, odontostyle 11-13 µm long, neck 673-868 µm long with the pharyngeal expansion occupying 66-77% of its length, anterior genital branch reduced to a uterine sac 75-135 µm long or 4-7% of body length, posterior uterus tetrapartite and including a Z-like differentiation, V = 51-55, and female tail short and rounded (37-51 µm, c = 66-97, c' = 0.5-0.7). Metaxonchium silvaticum sp. n is characterized by its 1.28-1.43 mm long body, lip region offset by weak depression and 7.0 µm broad, odontostyle 8-9 µm long, neck 502-630 µm long with the pharyngeal expansion occupying 65-76% of its length, anterior genital branch reduced to a uterine sac 65-80 µm long or 4-6% of body length, posterior uterus tripartite, non-echinophor, V = 52-57, tail short and rounded (18-23 µm, c = 56-74, c' = 0.6-0.8) with abundant blister-like or saccate bodies, spicules 41 µm long, and seven spaced ventromedian supplements.

The genus Metaporcelaimus Lordello, 1965 (Nematoda, Dorylaimida, Aporcelaimidae) in Ukraine: Description of one known and two new species without hiatus.

One known (M. romanicus) and two new species of the genus Metaporcelaimus, collected in natural and semi-natural habitats of Ukraine, are described and illustrated. Metaporcelaimus concinnus sp. n. is characterized by its 3.09-4.58 mm long body, lip region 16.5-19.5 µm broad and visibly wider than the adjacent body, odontostyle 17-19 µm long, neck 745-865 µm long, pharyngeal expansion occupying 62-66% of total neck length, uterus tripartite and 3.9-5.7 times the corresponding body diameter, vulva longitudinal (V = 49-53%), tail conical (44-54 µm, c = 67-94, c' = 1.0-1.3 in females), spicules 79-86 µm long with strongly bifurcate distal end, and 10-14 irregularly spaced ventromedian supplements without hiatus. Metaporcelaimus declivicaudatus sp. n. is characterized by its 2.88-3.66 mm long body, lip region 23-28 µm broad, odontostyle 24-26 µm long, neck 634-788 µm long, pharyngeal expansion occupying 48-56% of total neck length, uterus tripartite and 3.0-3.4 times the corresponding body diameter long, vulva transverse (V = 51-55%), tail conical (45-65 µm, c = 53-63, c' = 1.0-1.2) with rounded terminus, spicules 102-113 µm long, and 12-14 spaced ventromedian supplements without hiatus. New information about M. romanicus is also provided, confirming available data about this species.

A new species of the genus Aporcelinus Andrássy, 2009 (Nematoda, Dorylaimida, Aporcelaimidae) from Costa Rica.

A new species of the genus Aporcelinus, A. elongicaudatus sp. n., collected from natural habitats of Costa Rica, is described and illustrated. The new species is characterized by its 0.92-1.05 mm long body, lip region offset by weak constriction and 15 µm broad, odontostyle 15-18 µm or 1.0-1.2 times the lip region diameter, neck 270-300 µm long, pharyngeal expansion 130-150 µm long or 45-55% of total neck length, uterus 33-41 µm long or 0.70-0.85 times the corresponding body diameter (but certainly longer), vulva transverse (V = 49-51), and tail conical elongated (45-71 µm, c = 14-22, c' = 2.0-3.2) and dorsad bent.

Taxonomy and Systematics of the Genus Makatinus Heyns, 1965 (Nematoda: Dorylaimida: Aporcelaimidae).

The taxonomy and the systematics of the genus Makatinus are discussed by means of the characterization of its morphological pattern and the first molecular (D2-D3 expansion segments of 28S rDNA) analysis of a representative of this taxon, Makatinus crassiformis from Costa Rica. The presence of two or more pairs of male ad-cloacal genital papillae is the most characteristic autapomorphy of the genus, but the status of its species on this concern differ among them. Both morphological and molecular data support a relationship with Aporcelaimellus, which, however, might not be as close as usually assumed. An emended diagnosis of the genus, a key to species identification, and a compendium of their morphometrics are provided. Makatinus siddiqii is regarded as species inquirenda, Makatinus simus is retained under Eudorylaimus, and Makatinus tritici becomes a junior synonym of Aporcelaimellus tritici.

Myolaimus ibericus sp. n. (Nematoda, Rhabditida, Myolaimidae) from southern Iberian Peninsula, with a key to species of the genus.

A new species of the genus Myolaimus is described from agricultural areas in the southeast of the Iberian Peninsula. Myolaimus ibericus sp. n. is characterized by its 560-783 µm long body in females and 526-731 µm in males, cuticle often appearing swollen and baggy, lateral field with one longitudinal wing, lip region with six amalgamated lips having ten (6 + 4) setiform papillae, stoma consisting of a wider anterior chamber (cheilo-gymnostom) and a tubular posterior part (stegostom) separated by a well developed dorsal tooth and two small, lateral (one right and another left) teeth, glottoid-like apparatus structure appearing at metastom, pharyngeal corpus 1.7-2.6 times the isthmus length, excretory pore and deirids located at metacorpus level, deirids pore-like in females and seta-like in males, female reproductive system monodelphic-prodelphic with antidromous ovary, post-uterine sac 1.7-2.7 times the corresponding body diameter long, V = 50-56, female rectum 1.3-2.0 times the anal body diameter long, female tail conical-elongate (54-70 µm, c = 9.9-13.1, c' = 4.4-5.8) often enveloped by the baggy cuticle, male tail conoid (8-10 µm, c = 58.4-73.1, c' = 1.1-1.4) and ventrally constricted at its middle, bursal structure with seven (4+1+2) pairs of genital papillae. This is the first record of the genus from the Iberian Peninsula. Description, measurements and illustrations, including SEM photographs are provided. An illustrated compendium of the posterior ends of males in Myolaimus species is also presented.

Two new species of the rare genus Nygolaimoides Meyl in Andrássy, 1960 (Nematoda, Dorylaimida, Thorniidae) from Iran, with a compendium of its species.

Two new Nygolaimoides species are described and illustrated from soil and stumps of an old nursery of Populus alba, Miandoab County, West Azarbaijan province, Iran. Nygolaimoides zarrinensis sp. n. is characterized by its 0.73-0.94 mm long body, lip region 9.5-10.5 µm broad, odontostyle 9.5-11.0 µm long, neck length 162-194 µm long, pharyngeal expansion 78-83 µm long, V = 46-50, female tail short and rounded conoid (11-15 µm, c = 63-84, c' = 0.7-0.9), male tail rounded conoid (14-18 µm, c = 43-55, c' = 0.9-1.1), spicules 21-25 µm long and with irregular head, and two ventromedian supplements bearing hiatus. Nygolaimoides albus sp. n. is distinguished by its 0.64-0.95 mm long body, lip region 8-10 µm broad, odontostyle 9.5-11.0 µm long, neck length 164-200 µm long, pharyngeal expansion 66-72 µm long, V = 43-51, female tail hemispheroid (4.0-5.5 µm, c = 120-233, c' = 0.4-0.7), male tail conoid (9.0-12.0 µm, c = 58-78, c' = 0.7-1.0), spicules 13-17 µm long, and two ventromedian supplements bearing hiatus. SEM observations have been made for the first time for representatives of this genus. The taxonomy of the genus is updated with a list of its species, a key to their identification and a table-compendium of relevant morphometrics.

Re-description of Cephalobus topali Andrássy, 1970 (Rhabditida, Cephalobidae) from Vietnam, and transfer to Acrobeloides (Cobb, 1924) Thorne, 1937.

Recently, specimens of Cephalobus topali, collected from an agricultural area from northern Vietnam, are described, including SEM study. They are characterized by their its 306-347 µm long body in females, lateral field with two alae or 3-4 longitudinal incisures, lip region with three pairs of asymmetrical conoid lips, three low and rounded labial probolae separate from the corresponding pair of lips by an incisure, U-shaped primary axils without guard processes, V-shaped secondary axils without guard processes, pharyngeal corpus slightly fusiform and 2.6-3.1 times the isthmus length, spermatheca and postvulval sac poorly developed, female tail conoid (18-24 µm, c = 12.7-17.0, c' = 1.8-2.7) with rounded terminus ending in an acute or wart-shaped mucro, phasmid at 29-34% of tail length, and male unknown. SEM pictures reveal that lip region pattern significantly differs from that found in members of Cephalobus and fits that observed in Acrobeloides, so that the species is transferred to this genus. Cephalobus quadrilineatus is provisionally maintained as different from C. topali.

Two new species of the genus Aporcelinus Andrássy, 2009 (Nematoda, Dorylaimida, Aporcelaimidae) from Vietnam.

Two new species of Aporcelinus from Vietnamese natural habitats are studied, described and illustrated, including line drawings and light microscope (LM) pictures. Aporcelinus paramamillatus sp. n. is characterized by its 1.71-2.14 mm long body, lip region 21-22 µm broad, odontostyle 22-24 µm long at its ventral side, neck 451-503 µm long, uterus tripartite and 71-94 µm long, V = 53-54, tail conical with finely rounded tip, ending in a short peg-like terminus, occasionally slightly re-curved dorsad (24-34 µm, c = 50-77, c' = 0.6-0.9) and unknown male. Aporcelinus paraseychellensis sp. n. is distinguished by its 1.20-1.46 mm long body, lip region 16-18 µm broad, odontostyle 20 µm long at its ventral side, neck 354-368 µm long, uterus tripartite and 176-241 µm long, V = 52-54, tail conical with acute tip and hardly re-curved dorsad, spicules 62 µm long, and 12 regularly spaced ventromedian supplements lacking hiatus.