Transverse Vulva Research Articles

Morphological and Molecular Characterization of Discolaimus haridwarensis sp. n. (Nematoda: Dorylaimida: Qudsianematidae) from India

Discolaimus haridwarensis sp. n. is described from agricultural fields of sugarcane in the Haridwar district, India. It is characterized by its 2.11–2.32 mm long body, lip region offset by deep constriction and 27–30 μm wide, odontostyle 20–23 μm long with aperture occupying 50–54% of its length, 436–487 μm long neck, pharyngeal expansion 57–59% of total neck length, uterus a simple tube-like structure 22–31 μm long or 0.3–0.5 times the corresponding body diameter, pars refringens vaginae absent, transverse vulva (V = 48–55), female tail conoid (34–40 µm, c = 53–68, c′ = 1.0–1.3) with rounded terminus, and males absent. The phylogenetic analysis inferred from the D2-D3 expansion segments of 28S rRNA gene and 18S rRNA gene sequences showed that Discolaimus haridwarensis sp. n. clustered with other dorylaimid species from the genus Discolaimus and the subfamily Discolaiminae.

Morphological and molecular characterisation of Persinema enigmaticum gen. n., sp. n. (Nematoda, Dorylaimida), a new remarkable taxon from Iran

Summary A new genus is proposed to accommodate an undescribed dorylaimid form collected in Iran. Persianema gen. n. is characterised by its three-layered cuticle, oral field appreciably sunken but its perioral area visibly protruding, odontostyle less than one-half of lip region diam. and with large aperture, guiding ring simple and always located in front of odontostyle, odontophore 4-5 times longer than odontostyle, dorsal gland nucleus (DN) very posteriorly located, female genital system di-ovarian with well-developed pars refringens vaginae, tail short and rounded in both sexes, spicules dorylaimid and 3-4 spaced ventromedian supplements with hiatus. Its type and only species, P. enigmaticum sp. n., is described and illustrated, including SEM observations. It is distiguished by its 1.45-2.03 mm long body, lip region offset by shallow depression and 15.5-17.5 μm wide, odontostyle 6-7 μm long with aperture occupying more than half of its length, neck 285-340 μm long, pharyngeal expansion 38-43% of the total neck length, three gland cells present at pharyngo-intestinal junction, simple uterus 81-113 μm or 1.7-3.1 body diam. long, transverse vulva (V = 50-54), tail 15-25 μm long (c = 69-106, c′ = 0.6-0.8) and spicules 38-48 μm long. Molecular analysis of D2-D3 28S rDNA sequences revealed its closest similarity with Pungentus sequences, and an integrative comparison supports its belonging to Pungentinae.

Two new species of the genus Sectonema Thorne, 1930 (Nematoda, Dorylaimida, Aporcelaimidae) from Iran, with new insights into its evolutionary relationships.

Two new species of the genus Sectonema found in northern Iran are characterized, including morphological descriptions and molecular (18S-, 28S-rDNA) analyses. Sectonema tehranense sp. nov. is distinguished by its 7.22 - 8.53 mm long body, lip region offset by constriction and 24 - 31 μm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, mural tooth 15.5 - 17 μm long at its ventral side, neck 1091 - 1478 μm long, pharyngeal expansion occupying 61 - 71% of the total neck length, female genital system diovarian, uterus simple and 3.9 - 4.2 times the corresponding body diameter long, transverse vulva (V = 49 - 59), tail short and rounded (44 - 65 μm, c = 99 - 162, c' = 0.6 - 0.8), spicules 111 - 127 μm long, and 7 - 10 spaced ventromedian supplements with hiatus. Sectonema noshahrense sp. nov. displays a 4.07 - 4.73 mm long body, lip region offset by constriction and 23 - 25 μm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, odontostyle 14 - 14.5 μm long, neck 722 - 822 μm long, pharyngeal expansion occupying 66 - 68% of the total neck length, female genital system diovarian, uterus simple and 2.4 - 2.7 times the corresponding body diameter long, transverse vulva (V = 54 - 55), tail convex conoid (39 - 47 μm, c = 91 - 111, c' = 0.8 - 0.9), spicules 82 μm long, and seven spaced ventromedian supplements with hiatus. Molecular analyses confirm a maximally supported (Epacrolaimus + Metaporcelaimus + Sectonema) clade and a tentative biogeographical pattern, with sequences of Indolamayan taxa forming a clade separated from those of Palearctic ones. Parallel or convergent evolution processes might be involved in the phylogeny of the species currently classified under Sectonema. This genus is certainly more heterogeneous than previously assumed.

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 characterisation of Talanema maculatum sp. n. (Dorylaimida, Qudsianematidae) from Iran

Summary A new species of the genus Talanema, T. maculatum sp. n., collected in a natural enclave of Iran, is characterised on the basis of morphological and molecular data. It is distinguishable by its 1.82-2.20 mm long body, lip region offset by constriction and 20-23 μm wide with perioral liplets, odontostyle 21.5-28 μm long, guiding ring double, neck 394-525 μm long, pharyngeal expansion occupying 44-49% of the total neck length, uterus tripartite and 308-441 μm long or 5.1-6.8 body diam., vulva transverse (V = 54-58), presence of abundant cuticle irregularities at the perivulval area, tail similar in both sexes, conical with a dorsal concavity (31-45 μm, c = 46-71, c′ = 0.9-1.1), spicules 70-75 μm long, and 14-18 shortly spaced ventromedian supplements ending at level of the anterior end of spicules, with hiatus. Molecular analysis of 28S-rDNA gene confirms the monophyly of Talanema and the difficulties in elucidating its external evolutionary relationships.

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.

Morphological and molecular characterisation of Talanema ibericum sp. n. (Dorylaimida, Qudsianematidae) from southern Iberian Peninsula

Summary A new species of the genus Talanema, T. ibericum sp. n., collected in natural areas of southeastern Iberian Peninsula, is characterised, including morphological description, line, LM and SEM illustrations, and molecular (18S, D2-D3 28S rDNA sequences) study. The new species is distinguished by its 1.27-1.59 mm long body, lip region offset by constriction and 14-16.5 μm wide with perioral liplets, odontostyle 16.5-19.5 μm long, neck 285-359 μm long, pharyngeal expansion occupying 42-48% of the total neck length, uterus tripartite and 147-228 μm long or 2.6-4.0 body diam., vulva transverse (V = 53-59), presence of cuticular irregularities at both sides of vulva, female tail conical with a dorsal concavity (27-40 μm, c = 36-54, c′ = 1.0-1.3), male tail short and rounded conoid (24 μm, c = 66, c′ = 0.8), spicules 58 μm long, and 17 almost contiguous ventromedian supplements with hiatus. Morphological and molecular data reveal that the new species is similar to (but easily separable from) T. baqrii, with which it is compared. Present results support the monophyly of the genus Talanema.

Qudsialemellus keralaensis gen. et sp. nov. (Nematoda: Dorylaimida: Belondiridae) from Western Ghats of India

Qudsialemellus keralaensis, a new genus and species of belondirid nematode is described and illustrated from the tropical rain forests of Western Ghats, India. The new genus is characterized by its rounded and continuous lip region; odontostyle attenuated with solid appearing tip; odontophore with distinct basal flanges; spiral muscular sheath around the expanded part of pharynx; spathulate cardia; female genital system mono-opisthodelpic; vulva transverse; tail long filiform, similar in both sexes; male with dorylaimoid spicules and two spaced ventromedian supplements. It comes close to the genera Qudsiella Jairajpuri, 1967, Paraqudsiella Siddiqi, 1981 and Durinemella Andrássy, 2009 belonging to the subfamily Swangeriinae Jairajpuri, 1964 but distinctly differs from all the three genera in the presence of a thick walled odontostyle with its tip almost solid appearing and odontophore with prominent basal flanges.

Two new and two known species of the genus Paraoxydirus Jairajpuri and Ahmad, 1978 (Nematoda: Dorylaimida) from Western Ghats of India

SummaryTwo new and two known species of the genus Paraoxydirus Jairajpuri and Ahmad, 1978 are described and illustrated from Western Ghats of India. P. vulvalpapillatus n. sp. is characterized by having large sized body (L = 4.6 – 4.8 mm); lip region continuous with completely amalgamated lips; amphidial fovea cup – shaped; 5 – 6 μm long odontostyle; 11 – 13 μm long odontophore; pharyngeal expansion about 28 – 36 % of neck length; transverse vulva; vulval papillae conspicuous; males with 46 – 54 μm long spicules; 11 – 14 continuous ventromedian supplements and long filiform tail similar in both sexes. P. indicus n. sp. is characterized by having large sized body (L = 4.0 – 4.8 mm); lip region poorly offset with amalgamated lips; amphidial fovea cup-shaped; 7 – 8 μm long, robust odontostyle; 17 – 18 μm long odontophore; pharyngeal expansion about 32 – 40 % of neck length; 21 – 26 μm long cardia; longitudinal vulva; 748 – 894 μm long filiform tail; males with 45 – 54 μm long spicules and 12 – 15 continuous ventromedian supplements. P. gigas Jairajpuri, 1964 and P. novus Jairajpuri, 1965 are redescribed based on specimens collected from several localities. A diagnostic Key and compendium to the identification of its eight valid species is provided.

On the identity of Labronema baqrii Khan, Jairajpuri and Ahmad, 1989 (Nematoda, Dorylaimida) and analysis of the relationships between the genera Labronema Thorne, 1939 and Talanema Andrássy, 1991

Nematodes are among the most successful and diverse taxa in the animal kingdom, combine endless variation with a deceptively conserved anatomical pattern. Nematodes representing the Order Dorylaimida show K-strategies i.e. having a long life-cycle, low reproduction rate, low colonization ability and are sensitive to disturbance and usually live in a habitat with long durational stability, dominate both in number and species, over other soil-inhabiting nematodes. Andrássy while revising the family Qudsianematidae Jairajpuri, 1965 proposed the genus Talanema Andrássy, 1991 for Labronema Thorne, 1939 species having transverse vulva, subdigitate tail and non-contiguous ventromedian supplements. After almost three decades, the genus is still in need of scientific attention as the addition of new species and transfer of previously described Labronema species make a continuum between the Labronema and Talanema species. In the present work, a pure population of Labronema baqrii Khan, Jairajpuri & Ahmad, 1989 represented by males, females and juveniles isolated from cattle manure from Aligarh, Uttar Pradesh was studied. Herein, we transfer L. baqrii to Talanema and sought to clarify their relationship through molecular and morphological characterization of Talanema baqrii (Khan, Jairajpuri & Ahmad 1989) comb. n. along with the analysis of Labronema species with transverse vulva; conoid, rounded or digitate tail and non-contiguous ventromedian supplements.

Morphological and molecular characterization of Xiphinemella esseri Chitwood, 1957 (Dorylaimida: Leptonchidae) from Florida, with the first molecular study of the genus.

A population of Xiphinemella esseri, recently collected under the canopy of associated live oak trees in north Florida, was studied and described with an integrative approach, including the first molecular study of the genus. This Florida population is characterized by its 2.30 to 3.32 mm long body, labial disc well developed, lip region offset by constriction, and 16.5 to 17.5 μm broad, odontostyle 46 to 49 μm long with minute aperture, neck 288 to 296 μm long, pharyngeal expansion occupying 28 to 30% of total neck length, uterus a tripartite tube-like structure, pars refringens vaginae absent, vulva transverse (V = 45.4-49.7%), tail short and rounded (18-28 μm, c = 94-158, c′ = 0.6-0.9), spicules 41 to 45 μm long, and 8 to 10 irregularly spaced ventromedian supplements bearing hiatus. The phylogenetic analysis inferred from the D2-D3 expansion segments of 28S rRNA gene and 18S rRNA gene sequences showed that X. esseri clustered with other dorylaims from the family Leptonchidae. A brief discussion about the distribution and biological considerations of X. esseri is also provided.

Description of Aporcella minor sp. n. (Dorylaimida: Aporcelaimidae) from Iran, with an updated taxonomy of the genus

Summary A new species belonging to the genus Aporcella, collected in cultivated soils of East Azarbaijan province, Iran, is described and illustrated. The new species is characterised by its 1.08 (1.05-1.15) mm long body, two-layered cuticle, lip region offset by constriction and 12 (11-13) μm broad, odontostyle 13.0 (12.5-14.0) μm long or nearly equal to lip region diam., neck 310 (293-325) μm long, pharyngeal expansion 137 (128-144) μm long, occupying 43-45% of the total neck length, female genital system didelphic-amphidelphic, uterus simple, 34-48 μm long, vulva transverse (V = 59 (58-61)), tail conical with finely rounded terminus (30 (29-33) μm long, c = 34 (33-36), c′ = 1.5 (1.4-1.6)), and male absent. Molecular analyses, using Bayesian inference based on partial LSU sequences, confirm the monophyly of Aporcella as well as its clustering with other dorylaimid taxa characterised by the absence of pars refringens vaginae. The taxonomy of the genus is updated, with an emended diagnosis, list of species, key to their identification, and a compendium of the main morphometrics of species/populations described since the last available revision.

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.

Taxonomy of the Genus Lordellonema Andrássy, 1960 (Nematoda: Dorylaimida: Qudsianematidae) with Description of Three New Species

Three new species of the genus LordellonemaAndrassy, 1960 are described and illustrated. Lordellonema indicumsp. nov. has 0.9–1.1 mm long body; lip region offset by constriction with distinctly protruding labial papillae; odontostyle 13–15 µm long, with aperture occupying about 40–50% of its length; vulva pore-like; tail short, rounded and males absent. Lordellonema paramacrodorumsp. nov. has 1.0–1.2 mm long body; lip region distinctly offset, lips separate, rounded; odontostyle sinuate, 27–29 µm long, with aperture occupying about one-third of its length; vulva transverse; well-developed glandular cells present close to vagina; tail conical with rounded tip. Lordellonema spicularissp. nov. is characterized by its 1.2–1.4 mm long body; lip region angular, offset by constriction; odontostyle 15–16 µm long, aperture occupying 36–44% of its length; vulva transverse; tail convex conoid with blunt terminus; males with non-dorylaimid spicules, 5–7 irregularly spaced ventromedian supplements and lateral guiding pieces absent. Lordellonema porosum is redescribed here after more than five decades from Cabo Verde. L. rapsoides (Heyns et Lagerway, 1965) comb. nov. is redescribed here from Saudi Arabia. A diagnostic compendium of valid species is provided and comment has been made on their biogeography.

Two New Species of the Genus Coomansinema Ahmad and Jairajpuri, 1989 (Nematoda: Dorylaimida) with a Key to its Species.

SummaryTwo new species of the genus Coomansinema Ahmad and Jairajpuri, 1989 are described and illustrated. C. japonicum n. sp. is characterized by having medium size body (L= 1.40 – 1.45 mm); lip region truncate with completely amalgamated lips; amphideal fovea goblet – shaped; 16 – 20 μm long odontostyle; 23 – 25 μm long odontophore; comparatively anterior position of the second pair of pharyngeal glands; amphidelphic female genital system; longitudinal vulva; males with 48 – 54 μm long spicules; 7 – 8 spaced ventromedian supplements and tail long filiform in female and short conoid in male. C. longicaudatum n. sp. is characterized by having medium size body (L= 1.1 – 1.3 mm); lip region truncate, continuous with completely amalgamated lips; amphideal fovea cup – shaped; 16 – 17 μm long odontostyle; 19 – 20 μm long odontophore; comparatively anterior position of the second pair of pharyngeal glands; amphidelphic female genital system; transverse vulva, intestinal – prerectum junction with a tongue – like structure and 210 – 269 μm long filiform tail. A key to its seven valid species is provided.

A new species of the rare nematode genus Rostrulium Siddiqi, 1995 (Nematoda: Dorylaimida: Tylencholaimidae) from India.

Rostrulium indicum sp. n. is described and illustrated from Western Ghats, India. The new species is characterized by having a 2.1 mm long body; lip region offset by slight constriction; odontostyle 17.5 µm and odontophore 18 µm long, guiding ring single; pharynx with slender anterior part which expands gradually into the cylindrical basal bulb occupying about 30% of total neck length; female genital system didelphic-amphidelphic, transverse vulva, short rounded conoid tail and male with 40 µm long spicules, lateral guiding pieces and three spaced ventromedian supplements. This is the first report of this rare genus since its original description from Cameroon.

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.

Two new species of the genus Metaxonchium Coomans & Nair 1975 (Nematoda, Dorylaimida, Belondiridae) from Costa Rica, with new insights in the phylogeny of the family Belondiridae

Two new species of the genus Metaxonchium are described from natural habitats in Costa Rica. Metaxonchium parvisaccatum sp. n. is characterized by its 1.62–1.71 mm long body, lip region offset by constriction and 8.5–10 μm broad, odontostyle 10–11 μm long, neck 632–674 μm long, pharyngeal expansion occupying 68–71% of neck length, anterior genital branch reduced to a short uterine sac, 22–27 μm long or 1–2% of body length, posterior uterus long and tripartite without apophyses, vulva transverse (V = 54–55), caudal region short and rounded (23–26 μm, c = 62–76, c’ = 0.7–0.8), and male absent. Metaxonchium stenospiculum sp. n. is characterized by its 2.15–2.85 mm long body, lip region offset by constriction and 12.5–16 μm broad, odontostyle 13.5–16 μm long, neck 756–1011 μm long, pharyngeal expansion occupying 64–74% of neck length, anterior genital branch 8–13% of body length and consisting of a long uterine sac plus a terminal mass, posterior uterus long and tripartite without apophyses, vulva transverse (V = 53–59), caudal region short and rounded, nearly hemispheroid (20–28 μm, c = 91–126, c’ = 0.4–0.6) in females, and more conoid (29–41 μm, c = 80–88, c’ = 0.6–0.8) in males, spicules 96–102 μm long, and 11–14 spaced ventromedian supplements without hiatus. Molecular analysis of M. stenospiculum sp. n. D2-D3 LSU provides new insights in the phylogeny of Belondiridae as its rounded-tailed genera might constitute a monophyletic group.

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 of the genus Doryllium Cobb, 1920 (Nematoda: Dorylaimida) with description of two new and a known species.

Two new and a known species of the genus Doryllium Cobb, 1920 are described and illustrated. Doryllium enigmatum n. sp. is characterized by a body length of 0.40-0.52 mm; continuous lip region; rounded lips; asymmetrical odontostyle, 5-6 µm long, and flanged odontophore 9-11 µm in length; pharynx with slender anterior part which expands into a slightly constricted pyriform basal bulb, occupying about 16-18% of total neck length; mono-opisthodelphic female genital system; 7-9 μm long anterior uterine sac; transverse vulva and rounded-hemispheroid tail. Doryllium asymmetricum n. sp. is characterized by its 0.52-0.63 mm long body; cap-like, slightly offset lip region; asymmetrical odontostyle, 6 µm in length and 9-11 µm long odontophore with weak flanges; pharynx with slender anterior part which expands gradually into pear-shaped basal bulb, occupying about 16.4-18.5% of total neck length; mono-opisthodelphic female genital system; anterior uterine sac 17-30 μm in length, filled with sperms; transverse vulva and rounded-hemispheroid tail. D. minor is redescribed based on specimens collected from several localities in India and Germany. The diagnosis of the genus Doryllium is emended and a valid list of species with their synonymies and a diagnostic compendium of all the known species is provided.