taxonID	type	description	language	source
038687B8FFF8FFAFFDA2F8ADFE25FDFB.taxon	type_taxon	Type species Diplogastrellus gracilis (Bütschli, 1876).	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF8FFAFFDA2F8ADFE25FDFB.taxon	diagnosis	Diagnosis Body medium-sized. Cuticle usually appearing smooth. Stoma longer than wide. Cheilostom as long as gymnostom, with six flaps. Gymnostom anisotopic, dorsal gymnostomal wall being much shorter than subventrals. Stegostom anisotopic and anisomorphic; dorsal wall with dorsal flap or tooth. Subventral walls with a tooth or teeth or simply a ridge. Pharynx well-developed, muscular metacorpal bulb with valve plates, rounded to ovoid basal bulb. Female reproductive system mono-prodelphic or amphidelphic. Uterus divided into well-developed glandular and muscular parts. Genital sensilla nine pairs. Bursa absent. Tail long, filiform.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF9FFA4FDDBFDC2FAACFB5B.taxon	description	urn: lsid: zoobank. org: act: 1 B 249 AFA- 2213 - 4700 - A 004 - C 4771 D 5 BAF 20 Figs 1 – 2, 17 – 19; Tables 1, 7 – 8	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF9FFA4FDDBFDC2FAACFB5B.taxon	diagnosis	Diagnosis The new species Diplogastrellus didelphis sp. nov. is characterised by finely punctated cuticle (Fig. 2 H); a narrow stoma longer than wide; a medium-sized dorsal tooth with ventrally directed apex; amphidial apertures small, elliptical, at the base of gymnostom; oblong median bulb with valve plates and a pyriform basal bulb; amphidelphic reproductive system, a large uterine pouch filled with sperm (Fig. 2 I); spicules separate, strongly built, ventrally arcuate with a 90 º curvature; proximally sickle-shaped or notched with a long anteriorly-directed dorsal arm and a short ventral arm, distal end thin and delicate with a sleeve and nine pairs of genital sensilla.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF9FFA4FDDBFDC2FAACFB5B.taxon	etymology	Etymology The name of the species is based on the didelphic-amphidelphic gonad.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF9FFA4FDDBFDC2FAACFB5B.taxon	materials_examined	Material examined Holotype INDIA • ♀; Uttar Pradesh, District Muzaffarnagar; 29 ° 31 ′ 27 ″ N, 77 ° 38 ′ 38 ″ E; isolated from rotting banana rhizome; slide reference number AMU / ZD / NC / Diplogastrellus didelphis / 1. Paratypes INDIA • 9 ♀♀, 10 ♂♂; same data as for holotype; slide reference number AMU / ZD / NC / Diplogastrellus didelphis / 2 – 9.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF9FFA4FDDBFDC2FAACFB5B.taxon	description	Description Adult Body slender, less than 1 mm long; almost straight after fixation, tapering only very slightly anteriorly, but more posteriorly forming a filiform tail. Cuticle with fine transverse and longitudinal striations. Cuticular punctations fine, transversely arranged (Fig. 2 H). Lip region round, continuous with body contour. Lips six, amalgamated, each bearing a small papilliform labial sensilla. Amphidial apertures small, elliptical, 6 – 7 µm from anterior end of stoma, at the base of gymnostom. Stoma narrow, tubular, longer than wide, about 10 – 11 µm in depth. Cheilostom slightly longer than wide, cheilorhabdions arched inward anteriorly, cheilorhabdial flaps six, protruding above labial contour; gymnostom anisotopic, dorsal wall shorter than subventrals. Stegostom anisotopic and anisomorphic, dorsal metastegostomal wall with medium-sized tooth, with ventrally directed apex, subventral walls without armature. Pharynx with slender 65 – 78 µm long, muscular corpus of uniform diameter; median bulb set off from corpus, oblong, 23 – 29 µm long with strong valve plates. Isthmus 32 – 42 µm long, narrow, conspicuously differentiated from median bulb. Basal bulb small, pyriform, glandular, 12 – 15 × 9 – 10 µm, only slightly expanded from isthmus without any valve plate or grinder. Dorsal pharyngeal gland nucleus usually prominent, located near base of basal bulb. Nerve ring encircling isthmus in anterior half, located at 73 – 77 % of pharyngeal length. Hemizonid and excretory pore not visible. Cardia well-developed, 5 µm long, consisting of three flaps, one dorsal and two ventro-sublateral. Intestine composed of dark granulated cells with prominent nuclei, intestinal lumen uniformly wide, 5 – 6 µm without any bacterial pouch. Rectum 0.9 – 1.1 times anal body diameter long; rectal glands distinct. Female Reproductive system didelphic, amphidelphic, anterior gonad on right side and posterior on left side of intestine. Posterior branch usually smaller than the anterior. Ovaries long reversed, with distal part of ovaries not reaching the level of vulva. Oocytes with large nuclei, arranged in multiple rows in germinal zone and single row in maturation zone. Oviduct long, narrow, tubular. Spermatheca not set off from uterus, with distinctly narrower walls, containing sperm. Uterus divisible into a distal smaller muscular part and proximally placed longer, glandular part made up of large cells and narrow lumen. A large uterine pouch, 35 – 80 µm long, opens into reproductive tract at uterus-vagina junction, filled with sperm. Vagina narrow, tubular, almost at right angle to longitudinal body axis, 6 – 7 µm long about one-fourth of corresponding body diameter. Vulval opening small, elliptical, flushing with body contour. Vulva-anus distance 7.2 – 9.1 times vulval body diameter. Phasmids located at a level 1.3 – 1.7 of anal body diameter posterior to anus. Tail long, filiform 0.8 – 1.1 times vulva-anus distance, divided into two parts, an anterior short conoid part and a posterior longer filamentous part. Male Similar to females in general morphology but smaller in size. Reproductive system monorchic, testis reflexed laterally, on right side of intestine. Spermatocytes arranged in two rows distally followed by single row proximally. Vas deferens a long tube containing spermatocytes transforming into spermatozoa, tapering to an ejaculatory duct. Spicules paired, separate, strongly built, ventrally arcuate with a 90 º curvature, 1.4 – 1.7 times cloacal body diameter long. Manubrium round connected to calamus / lamina complex expanding into ventral conoid process, posteriorly tapering to a pointed distal tip. Gubernaculum stout, 58 – 61 % of spicule length, proximally sickle-shaped or notched with a long anteriorly-directed dorsal arm and a short ventral arm, distal end thin and delicate with a sleeve. Tail divisible into two parts, a short conoid part and a longer filamentous part. Genital sensilla nine pairs; three pairs precloacal and six pairs postcloacal. Genital sensilla formula: v 1, v 2 d, v 3 / v 4, ad, ph, (v 5, v 6, v 7), pd. Precloacal pair v 1 located more than one cloacal diameter anterior to cloaca; v 2 and v 3 closely placed; v 3 just anterior and v 4 closely posterior to cloaca; ad less than one cloacal body diameter posterior to cloaca, v 5 – 7 grouped; pd far posterior to v 7. Phasmids pore-like, 0.7 – 1.1 anal body diameter posterior to cloacal opening.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF9FFA4FDDBFDC2FAACFB5B.taxon	discussion	Remarks Diplogastrellus didelphis sp. nov. comes close to D. gracilis in most morphometric and morphological characteristics but differs in the shape of stoma (narrow, tubular vs comparatively broader), structure of dorsal tooth (anterio-ventral margin lacking serration vs serrated anterio-ventral margin), position of amphids (at the base of gymnostom vs at the base of cheilostom), female reproductive system (amphidelphic vs mono-prodelphic), uterine pouch (present vs absent), size and shape of spicules (30 – 31 µm; strongly built, calamus / lamina complex expanded into ventral conoid process vs 42 – 58 µm; long, attenuated, calamus / lamina complex not expanded), shape of gubernaculum (proximally notched with a long dorsal arm vs keel-like proximal part) and in the arrangement of genital sensilla (v 3 anterior to cloaca vs v 3 adcloacal). The new species differs from D. monhysteroides in the shape of dorsal tooth (ventrally directed apex vs anteriorly directed apex), shape of median bulb (oblong vs ovoid), female reproductive system (amphidelphic vs mono-prodelphic), uterine pouch (present vs absent), shape of spicules (strongly arcuate with a 90 º curvature to a pointed distal end vs smoothly arcuate to a curved distal end), structure of gubernaculum (proximally notched with a long dorsal arm, distal part thin with a sleeve vs proximally curved, distal part with a large rectangular sleeve) and arrangement of genital sensilla (v 2 anterior to cloaca far away from v 1 vs v 2 more anterior near the spicule head, close to v 1). The new species resembles D. metamasius in most morphometric characters but differs in having more slender body (a = 26.0 – 31.6 vs 16.1 – 22.2 in females), female reproductive system (amphidelphic vs mono-prodelphic), by uterine pouch (present vs absent), shape of spicules (strongly arcuate with a 90 º curvature vs slightly curved), structure of gubernaculum (proximally notched with a long dorsal arm, distal sleeve present vs proximally notched, sleeve absent) and arrangement of genital sensilla (v 2 anterior to cloaca within the spicular range vs v 2 more anterior beyond the spicule head). Diplogastrellus didelphis sp. nov. differs from D. graciloides in the position of amphids (at the base of gymnostom vs posterior to the base of stoma), female reproductive system (amphidelphic vs mono-prodelphic), uterine pouch (present vs absent), size of spicules (30 – 31 µm vs 24.5 µm), structure of gubernaculum (proximally notched with a long dorsal arm, distal sleeve present vs caudally projected keel-like without sleeve) and arrangement of genital sensilla (9 pairs; v 1 beyond the spicular range vs 8 pairs; v 1 located near the spicule head; v 7 absent). Diplogastrellus didelphis sp. nov. resembles Acrostichus medius Tahseen et al., 2016 in having didelphic reproductive system in females amphidelphic, and by presence of uterine pouch and stomal morphology. Acrostichus medius shows features common to both Diplogastrellus and Acrostichus; however, Diplogastrellus didelphis markedly differs from it in the structure of spicules (strongly arcuate with about 90 º curvature vs robust spicules with hood-like capitula, appearing deeply forked distally with fine extensions and a ventral attenuated arm) and gubernaculum (proximally notched with a long dorsal arm, distal sleeve vs curved and tapering proximal end and distal end with slight protuberances), bursa (absent vs with rudiments confined to posterior four genital pairs) in addition to other morphometric characters.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF2FFA2FDA6FB22FEFBFA18.taxon	description	urn: lsid: zoobank. org: act: DC 861 CBA-FAC 5 - 4440 - BC 5 A- 95190 CE 28528 Figs 3 – 5, 17 – 19; Tables 2, 7 – 8	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF2FFA2FDA6FB22FEFBFA18.taxon	diagnosis	Diagnosis The new species Diplogastrellus longipharyngis sp. nov. is characterised by a narrow stoma longer than wide; elliptical amphidial aperture, at the level of dorsal tooth; a medium-sized dorsal tooth with ventrally directed apex; pharynx well-developed, muscular ovoid metacorpal bulb with valve plates, a long isthmus and ovoid basal bulb; posterior pharynx 1.5 – 1.9 times anterior pharynx; mono-prodelphic reproductive system with a post-uterine sac filled with sperm; spicules separate, heavily cuticularized, slightly curved with small rounded manubrium; a proximally notched, keel-like triangular gubernaculum and nine pairs of genital sensilla.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF2FFA2FDA6FB22FEFBFA18.taxon	etymology	Etymology The name of the species is derived from the long isthmus part of pharynx.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF2FFA2FDA6FB22FEFBFA18.taxon	materials_examined	Material examined Holotype INDIA • ♀; Uttarakhand, District Haldwani; 29 ° 12 ′ 52 ″ N, 79 ° 31 ′ 40 ″ E; isolated from rotting bark; slide reference number AMU / ZD / NC / Diplogastrellus longipharyngis / 1. Paratypes INDIA • 9 ♀♀, 10 ♂♂; same data as for holotype; slide reference number AMU / ZD / NC / Diplogastrellus longipharyngis / 2 – 9.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF2FFA2FDA6FB22FEFBFA18.taxon	description	Description Adult Body slender, about 1 mm long, almost straight after fixation, tapering towards both the extremes. Cuticle with transverse striations. Lip region continuous with body contour. Lips six, amalgamated, each bearing a small papilla. Amphidial apertures elliptical, 5 – 6 µm from anterior end of stoma, at the level of dorsal tooth. Stoma short, tubular, longer than wide, about 5 – 6 µm in depth. Cheilostom as long as wide, cheilorhabdions arched inward anteriorly. Gymnostom anisotopic, dorsal wall shorter than subventrals. Stegostom anisotopic and anisomorphic, dorsal metastegostomal wall with a medium-sized tooth, with ventrally directed apex, posterior-ventral aspect strongly cuticularised; subventral walls without armature. Pharynx with slender 42 – 51 µm long, muscular corpus of uniform diameter; median bulb set off from corpus, ovoid, 11 – 15 µm long with strong valve plates. Isthmus 65 – 85 µm long, narrow, conspicuously differentiated from median bulb. Basal bulb bigger than the median bulb, glandular, 25 – 33 × 13 – 17 µm, only slightly expanded from isthmus without any valve plate or grinder. Posterior pharynx 1.5 – 1.9 times anterior pharynx. Dorsal pharyngeal gland nucleus usually prominent, located near base of basal bulb. Nerve ring encircling isthmus in the anterior half, at 46 – 51 % of pharyngeal length. Hemizonid conspicuous, just posterior to the nerve ring, at 51 – 56 % of pharyngeal length. Excretory pore posterior to hemizonid, at 55 – 59 % of pharyngeal length. Cardia well-developed, 5 – 6 µm long, consisting of three flaps, one dorsal and two ventro-sublateral. Intestine composed of dark granulated cells with prominent nuclei, intestinal lumen uniformly wide, 5 – 6 µm without any bacterial pouch. Rectum 1.2 – 1.5 times anal body diameter long; rectal glands distinct. Female Reproductive system mono-prodelphic. Ovary reversed on right side of intestine. Oocytes with large nuclei, arranged in multiple rows in germinal zone and single row in maturation zone. Distal tip of ovary not reaching vulva. Oviduct long, narrow, tube-like. Spermatheca expanded, set off from uterus with distinctly narrower walls, containing sperm. Uterus divisible into a distal smaller muscular part and proximally placed longer, glandular part made up of large cells and narrow lumen. Post-uterine sac 35 – 49 µm long, 2.0 – 2.5 times vulval body diameter, filled with sperm. Vagina narrow, tubular, slightly inclined anteriorly, 11 – 16 µm long about one-third of corresponding body diameter long. Vulval opening small, pore-like. Vulva-anus distance 5.5. – 7.0 times vulval body diameter. Phasmids located at 1.8 – 2.4 anal body diameter posterior to anus. Tail long, filiform 1.5 – 1.9 times vulva-anus distance. Male Similar to females in general morphology but smaller in size, curved in posterior region. Reproductive system monorchic, testis reflexed laterally, on right side of intestine. Spermatocytes arranged in two rows distally followed by single row proximally. Vas deferens a long tube containing spermatocytes transforming into spermatozoa, tapering to an ejaculatory duct. Spicules paired, separate, almost straight, heavily cuticularized, 1.4 – 1.6 times cloacal body diameter long. Manubrium small, rounded, lamina / calamus complex not expanded, smoothly tapering to a pointed distal tip. Gubernaculum 37 – 44 % of spicule length, proximally notched, appearing triangular, keel-like with a pointed distal end. Tail divisible into two parts, a short conoid part and a longer filamentous part. Genital sensilla nine pairs; three pairs precloacal and six pairs postcloacal. Genital sensilla formula: v 1, v 2, v 3 d / v 4, ad, (v 5, v 6), ph, v 7, pd. v 1 located beyond the spicular range, more than one cloacal body diameter anterior to cloaca; v 2 less than one cloacal body diameter anterior to cloaca; v 3 d slightly posterior to v 2; v 4 just posterior to cloaca; ad one cloacal body diameter posterior to cloaca; v 5 – 7 not grouped, v 5 and v 6 close to each other while v 7 situated more posteriorly at the level of pd. Phasmids pore-like, just posterior to v 6, 1.3 – 1.5 anal body diameter posterior to cloacal opening.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF2FFA2FDA6FB22FEFBFA18.taxon	discussion	Remarks Diplogastrellus longipharyngis sp. nov. comes close to D. heynsi (Kiontke & Sudhaus, 1996) in most morphometric and morphological characteristics but differs in the size of stoma (5 – 6 µm vs 11 – 13 µm), size of dorsal tooth (medium-sized, ventrally directed vs massive, ventrally directed), position of amphids (at the base of dorsal tooth vs posterior to the base of stoma), median bulb (ovoid vs oblong), isthmus (longer that procorpus vs shorter than procorpus), shape of spicules (strongly built, almost straight vs stout, strongly arcuate at the distal end), shape of gubernaculum (triangular, proximally notched vs short, keel-like, caudally projected loop) and in the arrangement of genital sensilla (v 4 just posterior to cloaca, v 5 – 7 not grouped vs v 4 more than one cloacal diameter posterior to cloaca, v 5 – 7 grouped). The new species resembles D. sikorai and D. stammeri Weingärtner, 1955 in general morphometric values. However, it can be easily distinguished from both species by its short tubular stoma, long isthmus and in the structure of gubernaculum without sleeve. It further differs from D. sikorai in having larger body size (L = 865 – 1091 µm vs 492 – 657 µm in females; 597 – 752 µm vs 395 – 470 µm in males), by structure of dorsal tooth (ventrally directed vs anteriorly directed), size of post-uterine sac (35 – 49 µm vs 19 – 31 µm), length of spicules (25 – 27 µm vs 17 – 19 µm) and arrangement of genital papillae (v 1 anterior to spicule head, v 7 more posterior at the level of pd vs v 1 within the spicule range, v 5 – v 7 grouped). From D. stammeri, it can be further differentiated in the shape of dorsal tooth (ventrally directed vs anteriorly directed), position of amphids (at the base of dorsal tooth vs at the base of gymnostom), subventral armature (absent vs small tooth in both walls), size of post-uterine sac (more than twice vulval body diameter long vs less than one vulval body diameter) and structure of spicules (almost straight with rounded manubrium, anteriorly flattened, merging with shaft vs arcuate with ovoid manubrium separated from shaft by neck). The new species differs from D. thoubalicus in having shorter stoma (5 – 6 µm vs 12 – 15 µm), by position of amphids (at the base of dorsal tooth vs posterior to the base of stoma), median bulb (ovoid vs oblong), isthmus (longer that procorpus vs shorter than procorpus), shape of spicules (strongly built, almost straight vs slender, distally more curved), shape of gubernaculum (triangular, proximally notched vs posterio – dorsally directed loop with a small sleeve) and in the arrangement of genital sensilla (v 4 just posterior to cloaca, v 5 – 7 not grouped vs v 4 more than one cloacal diameter posterior to cloaca, v 5 – 7 grouped).	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF4FFB8FDDDFA67FB42F843.taxon	description	urn: lsid: zoobank. org: act: 36 D 4 BB 43 - EC 22 - 481 D-BE 18 - CDDF 4784140 D Figs 6 – 8, 17 – 19; Tables 3, 7 – 8	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF4FFB8FDDDFA67FB42F843.taxon	diagnosis	Diagnosis The new species Diplogastrellus robustus sp. nov. is characterised by a narrow stoma longer than wide; small, elliptical amphidial aperture, at the level of gymnostom; a medium-sized dorsal tooth with ventrally directed apex; pharynx well-developed, muscular ovoid metacorpal bulb with valve plates, narrow isthmus and a pyriform basal bulb; amphidelphic or mono-prodelphic reproductive system with a post-uterine sac; spicules robust, heavily cuticularized, smoothly curved to a blunt distal end; boat-like gubernaculum with a sleeve and nine pairs of genital sensilla.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF4FFB8FDDDFA67FB42F843.taxon	etymology	Etymology The name of the species is based on the robust spicule.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF4FFB8FDDDFA67FB42F843.taxon	materials_examined	Material examined Holotype INDIA • ♀; Kerala, District Kottayam; 9 ° 35 ′ 55 ″ N, 76 ° 30 ′ 39 ″ E; isolated from soil near ginger plantation; slide reference number AMU / ZD / NC / Diplogastrellus robustus / 1. Paratypes INDIA • 10 ♀♀, 10 ♂♂; same data as for holotype; slide reference number AMU / ZD / NC / Diplogastrellus robustus / 2 – 9.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF4FFB8FDDDFA67FB42F843.taxon	description	Description Adult Body slender, medium-sized, less than 1 mm long; almost straight after fixation, tapering only very slightly anteriorly, but more posteriorly forming a filiform tail. Cuticle with fine transverse striations. Lip region round, continuous with body contour. Lips six, amalgamated, each bearing a small papilliform labial sensilla. Amphidial apertures small, elliptical, 5 – 6 µm from anterior end of stoma, at the level of gymnostom. Stoma longer than wide, about 9 – 11 µm in depth. Cheilostom longer than wide, cheilorhabdions arched inward anteriorly, cheilorhabdial flaps six, protruding above labial contour; gymnostom anisotopic, dorsal wall shorter than subventrals. Stegostom anisotopic and anisomorphic, dorsal metastegostomal wall with a ventrally directed medium-sized tooth. Posterio-ventral aspect of dorsal tooth heavily cuticularized, supported posteriorly by cuticularised ridge. Subventral walls without armature. Pharynx with slender 78 – 88 µm long, muscular corpus of uniform diameter; median bulb set off from corpus, ovoid, 21 – 25 µm long with strong valve plates. Isthmus 33 – 57 µm long, narrow, conspicuously differentiated from median bulb. Basal bulb small, pyriform, glandular, 18 – 21 × 14 – 17 µm, only slightly expanded from isthmus without any valve plate or grinder. Nerve ring encircling isthmus in the middle or sometimes in the anterior half, located at 64 – 76 % of pharyngeal length. Hemizonid posterior to nerve ring, 65 – 85 % of pharyngeal length. Excretory pore posterior to hemizonid, 69 – 88 % of pharyngeal length. Cardia well-developed, 3 – 4 µm long, consisting of three flaps, one dorsal and two ventro-sublateral. Intestine composed of dark granulated cells with prominent nuclei and intestinal lumen uniformly wide, 8 – 10 µm without any bacterial pouch. Rectum 1.0 – 1.2 times anal body diameter long; rectal glands distinct. Female Reproductive system mono-prodelphic or amphidelphic. Anterior branch on the right and posterior on the left side of intestine. Ovary long reversed, extending beyond the level of vulva. Oocytes with large nuclei, arranged in multiple rows in germinal zone and single row in maturation zone. Oviduct narrow, tubular. Spermatheca expanded, not set off from uterus, with distinctly narrower walls, containing sperm. In most specimens, posterior genital branch appears to be reduced with sperm in the anterior part and vacuolated, degenerated cells in posterior part; sometimes posterior branch represented by a post-uterine sac. In two specimens, the posterior genital branch appeared well-developed and functional (amphidelphic). Uterus divisible into a distal smaller muscular part and proximally placed longer, glandular part made up of large cells and narrow lumen. Vagina short, at right angle to longitudinal body axis, 7 – 8 µm or about one-fourth of corresponding body diameter long. Vulval opening large, elliptical. Vulva-anus distance 5.6 – 7.9 times vulval body diameter. Phasmids located at a level 1.1 – 1.5 anal body diameter posterior to anus. Males Similar to females in general morphology but smaller in size. Reproductive system monorchic, testis reflexed laterally, on right side of intestine. Spermatocytes arranged in two rows in anterior reflexed part, well-developed spermatocytes in anterior half of non-reflexed part. Vas deferens a long tube narrowing posteriorly to form an ejaculatory duct. Spicules robust, strongly ventrally arcuate 1.2 – 1.5 times cloacal body diameter long. Manubrium hood-like, lamina / calamus complex expanded posterior to manubrium, and then smoothly tapering to a blunt distal tip. Gubernaculum slender, boat-shaped, 51 – 56 % of spicule length, proximally curved, provided with a sleeve followed by a pointed distal end. Tail divisible into two parts, a short conoid part and a longer filamentous part. Genital sensilla nine pairs; three pairs precloacal and six pairs postcloacal. Genital sensilla formula: v 1, v 2, v 3 d, v 4, ad, ph, (v 5, v 6, v 7), pd. Precloacal pair v 1 located just anterior to the spicule head; v 2 and v 3 d at the same level, anterior to cloaca and v 4 posterior to cloaca, ad less than one cloacal body diameter posterior to cloaca, v 5 – 7 grouped, located just anterior to base of filiform tail spike. Phasmids pore-like, posterior to ad, 1.0 – 1.3 anal body diameter posterior to cloacal opening; pd slightly posterior to v 7.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFF4FFB8FDDDFA67FB42F843.taxon	discussion	Remarks Diplogastrellus robustus sp. nov. comes close to D. graciloides in most morphometric and morphological characteristics but differs in having more robust body (MBD = 27 – 41 µm vs 20 – 26 µm in females; 26 – 38 µm vs 18 – 21 µm in males), by position of amphids (at the level of gymnostom vs posterior to the base of stoma), shape of median bulb (ovoid vs oblong), length of the flexure of ovary (extending beyond the level of vulva vs not reaching the level of vulva), structure of spicules (robust, hood-like manubrium, blunt distal end vs slender, rounded manubrium, curved distal end), structure of gubernaculum (slender, boat-shaped, with distal sleeve vs globose, keel-like projection, without distal sleeve) and number of genital papillae (9 pairs; v 4 less than one cloacal diameter posterior to cloaca vs 8 pairs; v 4 more than one cloacal diameter posterior to cloaca, v 7 absent). The new species differs from D. metamasius in the shape of median bulb (ovoid vs oblong), position of vulva (posteriorly located, 59 – 64 % vs anterior, 48 – 56 %), size of post-uterine sac (longer than vulval body diameter vs shorter than vulval body diameter), shape and size of spicules (31 – 36 µm; hood-like manubrium, with blunt distal end, vs 23.0 – 30.5 µm; small rounded manubrium, with pointed distal end), shape of gubernaculum (boat-shaped with distal sleeve vs keel-like without distal sleeve) and arrangement of genital sensilla (v 4 slightly less than one cloacal diameter posterior to cloaca vs v 4 just posterior to cloacal slit). Diplogastrellus robustus sp. nov. differs from the new species D. didelphis sp. nov. in the position of amphids (at the anterior part of gymnostom vs at the base of gymnostom), shape of median bulb (ovoid vs oblong), length of the flexure of ovary (extending beyond the level of vulva vs not reaching the level of vulva), uterine pouch (absent vs present), structure of spicules (robust, hood-like manubrium, calamus / lamina complex not expanded with blunt distal end vs slender, rounded manubrium, calamus / lamina complex expanded into ventral conoid process with pointed distal end), structure of gubernaculum (boat-shaped, with distal sleeve vs proximally sickle-shaped, long curved dorsal arm and a short ventral arm with a distal sleeve) and arrangement of genital papillae (pd slightly posterior to v 7 vs pd far posterior to v 7). Diplogastrellus robustus sp. nov. also differs from the new species D. longipharyngis sp. nov. in having more robust body (MBD = 26 – 38 µm vs 20 – 23 µm in males), position of amphids (at the anterior part of gymnostom vs at the base of dorsal tooth), length of stoma (10 – 12 µm vs 5 – 6 µm in females; 9 – 11 µm vs 6 µm in males), isthmus (shorter than corpus vs longer than corpus), length of the flexure of ovary (extending beyond the level of vulva vs not reaching the level of vulva), size and shape of spicules (31 – 36 µm; robust, hood-like manubrium, with blunt distal end vs 25 – 27 µm, slender, rounded manubrium with pointed distal end), structure of gubernaculum (boat-shaped, with distal sleeve vs triangular, proximally notched without distal sleeve) and arrangement of genital papillae (v 7 grouped and pd slightly posterior to v 7 vs v 7 separated from v 5, v 6 and pd at the level of v 7).	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFEFFFB6FDA2FE81FDDAFB7D.taxon	description	Figs 9 – 11, 17 – 19; Tables 4, 7 – 8	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFEFFFB6FDA2FE81FDDAFB7D.taxon	diagnosis	Emended diagnosis Diplogastrellus gracilis is characterised by a stoma longer than wide; cuticle with transverse and longitudinal striations; elliptical amphidial aperture, at the base of cheilostom; massive dorsal tooth with ventrally directed apex, anterio-ventral margin serrated; small tooth on each subventral wall; pharynx well-developed, muscular oblong metacorpal bulb with valve plates, narrow isthmus and a pyriform basal bulb; mono-prodelphic reproductive system; spicules thin, long, attenuated, strongly arcuate with oval manubrium, smoothly arcuate to a pointed distal end; gubernaculum 33 – 40 % of spicule length, with lateral sleeve at distal end surrounding terminal region of spicules and a prominent, keel-like proximal part. and nine pairs of genital sensilla – constituting two precloacal, two adcloacal and five postcloacal pairs.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFEFFFB6FDA2FE81FDDAFB7D.taxon	materials_examined	Material examined INDIA • 10 ♀♀, 10 ♂♂; Uttar Pradesh, District Aligarh; 27 ° 54 ′ 24 ″ N, 78 ° 4 ′ 36 ″ E; extracted from rotting banana rhizome; slide reference number AMU / ZD / NC / Diplogastrellus gracilis / 1 – 10.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFEFFFB6FDA2FE81FDDAFB7D.taxon	description	Description Adult Body slender, medium-sized, less than 1 mm long; almost straight after fixation, tapering only very slightly anteriorly, but more posteriorly forming a filiform tail. Cuticle with fine transverse and longitudinal striations. Cuticular punctations fine, transversely arranged. Lateral fields with two conspicuous spaced ridges about 8.6 – 12.0 % of maximum body width. Lip region continuous with body contour. Lips six, amalgamated, bearing a small papilla each. Amphidial apertures elliptical, 3 µm from anterior end of stoma, at the base of cheilostom. Stoma longer than wide, about 8 – 11 µm in depth. Cheilostom longer than wide, cheilorhabdions straight, cheilorhabdial flaps six, protruding above labial contour, gymnostom anisotopic, dorsal wall shorter than subventrals. Stegostom anisotopic and anisomorphic, dorsal metastegostomal wall with a large dorsal tooth, bulging into stoma, apex ventrally directed almost reaching the base of the ventral gymnostomal wall. Posterio-ventral aspect of tooth strongly cuticularised, concave; anterio-ventral aspect not cuticularised with an irregular surface. Subventral walls with small tooth each. Pharynx with slender 58 – 79 µm long, muscular corpus of uniform diameter; median bulb set off from corpus, oblong, 17 – 22 µm long with strong valve plates. Isthmus 23 – 40 µm long, narrow, conspicuously differentiated from median bulb. Basal bulb small, pyriform, glandular, 14 – 17 × 10 – 13 µm, only slightly expanded from isthmus without any valve plate or grinder. Nerve ring encircling isthmus in anterior half, located at 70 – 84 % pharyngeal length. Excretory pore and hemizonid inconspicuous. Deirids at the level of basal bulb. Cardia small, 3 – 4 µm long, consisting of three flaps, one dorsal and two ventro-sublateral. Intestine composed of dark granulated cells with prominent nuclei intestinal lumen uniformly 11 – 13 µm wide, without any bacterial pouch. Rectum 1.0 – 1.6 times anal body diameter long; rectal glands distinct. Female Reproductive system mono-prodelphic. Ovary reversed on right side of intestine, distal part of ovary not reaching the level of vulva. Oocytes with large nuclei, arranged in multiple rows in germinal zone and single row in maturation zone. Oviduct long, narrow, connecting spermatheca and ovary. Spermatheca expanded, generally filled with sperm, continuous with oviduct but separated by a constriction from uterus. Uterus divisible into a distal smaller muscular part and proximally placed longer glandular part made up of large cells and narrow lumen. Vagina tubular, inclined anteriorly, 11 – 13 µm long about half of the corresponding body diameter long. Vulval opening circular, vulval lips slightly protuberant. Post-uterine sac absent. Vulva-anus distance 1.0 – 1.7 times vulval body diameter. Phasmids located at about 1.3 – 2.1 anal body diameter posterior to anus. Tail long, filiform 4.8 – 7.8 times vulva-anus distance. Male Similar to females in general morphology but smaller in size. Reproductive system monorchic, testis reflexed laterally, on right side of intestine. Spermatocytes arranged in two rows in anterior reflexed part, well-developed spermatocytes in anterior half of non-reflexed part, as multiple rows in next half and containing small sperm in remaining gonad. Vas deferens a long tube tapering to an ejaculatory duct. Spicules long, thin, attenuated, strongly arcuate, 2.6 – 2.9 times cloacal body diameter long. Capitulum oval, calamus / lamina smoothly attenuated towards a pointed distal tip. Gubernaculum 33 – 40 % of spicule length, with lateral sleeve and a prominent, proximal keel-like part. Tail divisible into two parts, a short conoid part and a longer filamentous part. Genital sensilla nine pairs; two pairs precloacal, two pairs adcloacal and five pairs postcloacal. Genital sensilla formula: v 1, v 2 d, v 3 / v 4, ad, ph, (v 5, v 6, v 7), pd. Precloacal pair v 1 located more than one cloacal body diameter anterior to cloaca; v 2 d slightly anterior to cloaca; v 3 and v 4 adcloacal; ad less than one cloacal body diameter posterior to cloaca; pd far posterior to v 7. Phasmids pore-like, at the level of v 5, 0.7 – 0.9 anal body diameter posterior to cloacal opening.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFEFFFB6FDA2FE81FDDAFB7D.taxon	discussion	Remarks The original description of D. gracilis was given by Bütschli (1876) and further described or reported by Goodey (1929), Paramonov (1952), Weingärtner (1955), Timm (1961) and Kiontke & Sudhaus (1996). Later, Khan et al. (2008) provided the detailed description of the species collected from compost of mushroom, India. Our specimens’ descriptions and morphometric measurements concur well with those of the original specimens of D. gracilis described by Bütschli (1876). However, differences were observed in total length of body in both sexes (L = 735 – 817 µm vs 1350 – 1390 µm in females and 536 – 733 µm vs 1000 – 1070 µm in males), longer pharynx (b = 4.9 – 6.4 vs 7.3) in females, longer tail (c = 4.8 – 5.7 vs 7.1) in males, and structure of dorsal tooth (massive tooth with serrated anterior-ventral margin vs smaller tooth lacking serration). The population reported by Khan et al. (2008) indicates a wide range of values (L = 666 – 750 µm, a = 26.8 – 32.6, b = 5.2 – 5.9, c = 3.5 – 3.8, c’ = 11.1 – 12.0, V = 67.3 – 68.9 % in females; spicule = 50 – 57 µm, gubernaculum = 20 – 25 µm) which nearly overlapped with the values of our population.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE0FFB3FD9DFB41FE34FE29.taxon	description	Figs 12 – 13, 17 – 19; Tables 5, 7 – 8	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE0FFB3FD9DFB41FE34FE29.taxon	diagnosis	Emended diagnosis Diplogastrellus graciloides is characterised by a narrow stoma longer than wide; elliptical amphidial aperture, posterior to the base of stoma; massive dorsal tooth with ventrally directed apex, small tooth on each subventral wall; pharynx well-developed, muscular oblong metacorpal bulb with valve plates, narrow isthmus and a pyriform basal bulb; mono-prodelphic reproductive system with a post-uterine sac; spicules slender with oval manubrium, smoothly arcuate to a curved distal end; globose gubernaculum with serrated proximal part and pointed distal tip and eight pairs of genital sensilla – with three precloacal and five postcloacal pairs and v 7 absent.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE0FFB3FD9DFB41FE34FE29.taxon	materials_examined	Material examined INDIA • 10 ♀♀, 10 ♂♂; Uttar Pradesh, District Muzaffarnagar; 29 ° 31 ′ 27 ″ N, 77 ° 38 ′ 38 ″ E; extracted from rotting banana rhizome; slide reference number AMU / ZD / NC / Diplogastrellus graciloides / 1 – 10.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE0FFB3FD9DFB41FE34FE29.taxon	description	Description Adult Body slender, medium-sized, less than 1 mm long; almost straight after fixation, tapering only very slightly anteriorly, but more conspicuously posteriorly to a long filiform tail. Cuticle with fine transverse striations, lateral fields inconspicuous. Lip region round, continuous with body contour. Lips six, amalgamated, each bearing a small papilla. Amphidial apertures elliptical, 13 – 14 µm from anterior end, just posterior to the base of stegostom. Stoma narrow, longer than wide, about 9 – 11 µm in depth. Cheilostom longer than wide, cheilorhabdions arched inward anteriorly, cheilorhabdial flaps six, protruding above labial contour; gymnostom anisotopic, dorsal wall shorter than subventrals. Stegostom anisotopic and anisomorphic, dorsal metastegostomal wall with a large tooth, having ventrally directed apex. Posterio-ventral aspect strongly cuticularized, smooth. Anterio-dorsal aspect not cuticularized. Each subventral wall provided with a small tooth. Pharynx with slender 74 – 89 µm long, muscular corpus of uniform diameter; median bulb set off from corpus, elongate, 22 – 30 µm long with strong valve plates. Isthmus 38 – 48 µm long, narrow, conspicuously differentiated from median bulb. Basal bulb small, pyriform, glandular, 13 – 21 × 9 – 12 µm, only slightly expanded from isthmus without any valve plate or grinder. Nerve ring encircling isthmus in anterior half, located at 66 – 71 % of pharyngeal length. Hemizonid posterior to nerve ring, 67 – 72 % of pharyngeal length. Excretory pore just posterior to hemizonid, 70 – 74 % of pharyngeal length. Cardia well-developed, 3 µm long, consisting of three flaps, one dorsal and two ventro-sublateral. Intestine composed of dark granulated cells with prominent nuclei, intestinal lumen 6 – 8 µm wide, without any bacterial pouch. Rectum 1.0 – 1.4 times anal body diameter long; rectal glands distinct. Female Reproductive system mono-prodelphic. Ovary reversed on right side of intestine, distal part of ovary not reaching the level of vulva. Oocytes with large nuclei, arranged in multiple rows in germinal zone and single row in maturation zone. Oviduct long, narrow, tubular, connecting spermatheca and ovary. Spermatheca expanded, not set off from uterus but with distinctly narrower walls, containing sperm. Uterus divisible into a distal smaller muscular part and proximally placed longer glandular part made up of large cells and narrow lumen. Vagina narrow, tubular, almost at right angle to longitudinal body axis, 5 – 6 µm long, about one-fifth of corresponding body diameter. Vulval opening circular. Post-uterine sac 33 – 51 µm long, more than one vulval diameter long, sometimes filled with sperm. Vulva-anus distance 6.4 – 7.0 times vulval body diameter. Phasmids located at about 1.7 – 2.2 anal body diameter posterior to anus. Tail long, filiform 1.7 – 2.2 times vulva-anus distance. Male Similar to females in general morphology but smaller in size. Reproductive system monorchic, testis reflexed laterally, on right side of intestine. Spermatocytes arranged in two rows distally followed by single row proximally. Vas deferens a long tube containing spermatocytes transforming into sperm, tapering to an ejaculatory duct. Spicules paired, ventrally strongly arcuate, 1.3 – 1.4 times cloacal body diameter long. Manubrium oval, calamus / lamina complex smoothly tapered to a curved distal end. Gubernaculum globose, 45 – 50 % of spicule length, proximal part serrated, caudally projected keel-like with pointed distal tip. Tail divisible into two parts, a short conoid part and a longer filamentous part. Genital sensilla eight pairs; three precloacal and five postcloacal pairs. Genital sensilla in configuration v 1, v 2 d, v 3 / v 4, ad, ph, (v 5, v 6), pd. Precloacal pair v 1 located anterior to the spicule range, almost one cloacal body diameter anterior to cloaca; v 3 just anterior to cloaca; v 2 d slightly anterior to v 3; v 4 more than one cloacal body diameter posterior to cloaca and slightly anterior to ad; v 5, v 6 posterior to ad, v 7 absent. Phasmids pore-like, 1.8 – 2.3 anal body diameter posterior to cloacal opening.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE0FFB3FD9DFB41FE34FE29.taxon	discussion	Remarks The original description of D. graciloides was given by Skwarra (1921) collected from farmyard manure, Kaliningrad, Russia. The morphometric measurements of D. graciloides of our sample concur well with that of Skwarra (1921). However, minor differences were observed in body size (L = 769 – 865 µm vs 1000 – 1670 µm in females; 699 – 857 µm vs 860 – 1220 µm in males), position of amphids (just posterior to the base of stoma vs far posterior to the base of stoma) and shape of spicules (distally curved vs not curved). Our population of Diplogastrellus graciloides shows resemblance with its closely related species D. gracilis. However, it differs in having longer tail (c = 2.6 – 3.1 vs 3.5 – 3.8 in females; 2.7 – 3.1 vs 5.3 – 7.6 in males), position of amphids (at the base of cheilostom vs posterior to the base of stoma), post-uterine sac (present vs absent), size and shape of spicules (19 – 20 µm; strongly arcuate, smoothly tapered to a curved distal end vs 50 – 57 µm; long, thin, slender, attenuated to a pointed distal end), size and shape of gubernaculum (9 – 10 µm; globose with pointed distal tip vs 20 – 25 µm; keel-like proximal end with a distal sleeve).	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE5FF84FE70FD94FB03FE73.taxon	description	Figs 14 – 19; Tables 6 – 8	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE5FF84FE70FD94FB03FE73.taxon	diagnosis	Emended diagnosis Diplogastrellus monhysteroides is characterised by a broad stoma longer than wide; elliptical amphidial aperture, at the base of stoma; strong, dagger-like dorsal tooth, anteriorly-directed and small tooth on both subventral walls; pharynx well-developed, muscular ovoid metacorpal bulb with valve plates, narrow isthmus and an oval basal bulb; mono-prodelphic reproductive system with a post-uterine sac; spicules slender with rounded manubrium, strongly arcuate to a curved and pointed distal end; shoe-like gubernaculum, distal end with a rectangular sleeve and nine pairs of genital sensilla.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE5FF84FE70FD94FB03FE73.taxon	materials_examined	Material examined INDIA • 10 ♀♀, 10 ♂♂; Uttar Pradesh, District Bulandshahr; 28 ° 16 ′ 22 ″ N, 78 ° 1 ′ 29 ″ E; extracted from farmyard manure; slide reference number AMU / ZD / NC / Diplogastrellus monhysteroides / 1 – 10.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE5FF84FE70FD94FB03FE73.taxon	description	Description Adult Body slender, medium-sized, less than 1 mm long; almost straight after fixation, tapering at both extremities. Cuticle with fine transverse striations, longitudinal ridges faint. Lip region round, continuous with body contour. Lips six, amalgamated, each bearing a setose papilla. Amphidial apertures oval, 7 – 9 µm from anterior end of stoma, at the base of dorsal tooth. Stoma broad, 9 – 11 µm long. Cheilostom longer than wide, cheilorhabdions arched inward anteriorly, cheilorhabdial flaps six, protruding above labial contour; gymnostom anisotopic, dorsal wall shorter than subventrals. Stegostom anisotopic and anisomorphic, dorsal metastegostomal wall with a strong, dagger-like, anteriorly-directed tooth, 3 – 4 µm long; subventral walls provided with small tooth each. Pharynx with slender 54 – 62 µm long, muscular corpus of uniform diameter; median bulb set off from corpus, ovoid, 15 – 16 µm long with strong valve plates. Isthmus 29 – 37 µm long, narrow, conspicuously differentiated from median bulb. Basal bulb oval, glandular, 13 – 16 × 11 – 14 µm, only slightly expanded from isthmus without any valve plate or grinder. Nerve ring encircling isthmus in anterior half, located at 69 – 72 % pharyngeal length. Excretory pore and hemizonid not visible. Cardia well-developed, 5 – 6 µm long, consisting of three flaps, one dorsal and two ventro-sublateral. Intestine composed of dark granulated cells with prominent nuclei, intestinal lumen uniformly wide, 5 – 7 µm without any bacterial pouch. Rectum 1.4 – 1.7 times anal body diameter long, three rectal glands, one dorsal and two subventral, observed at intestine – rectum junction Female Reproductive system mono-prodelphic. Ovary reversed on right side of intestine, distal part of ovary not reaching the level of vulva. Oocytes with large nuclei, arranged in multiple rows in germinal zone and single row in maturation zone. Oviduct long, narrow, tubular, connecting spermatheca and ovary. Spermatheca expanded, not set off from uterus, with distinctly narrower walls, containing sperm. Uterus divisible into a distal small muscular and proximally placed longer, glandular part made up of large cells and narrow lumen. Vagina narrow, tubular, almost at right angle to longitudinal body axis, 11 – 14 µm long about one-third of corresponding body diameter. Vulval opening circular. Post-uterine sac 27 – 40 µm long, sometimes filled with sperm. Vulva-anus distance 4.1 – 5.2 times vulval body diameter. Phasmids located at 1.3 – 1.8 anal body diameter posterior to anus. Tail long, filiform 2.7 – 3.6 times vulva-anus distance. Male Similar to females in general morphology but smaller in size. Anterior region with four cephalic papillae present posterior to circlet of six labial papillae. Reproductive system monorchic, testis reflexed ventrally, on right side of intestine. Spermatocytes arranged in two rows in anterior reflexed part, well-developed spermatocytes in anterior half of non-reflexed part, as multiple rows in next half and containing small sperm in remaining gonad. Vas deferens a long tube tapering to an ejaculatory duct. Spicules paired, slender, ventrally arcuate, 1.7 – 1.8 times cloacal body diameter long. Manubrium rounded, calamus / lamina complex slightly expanded and smoothly tapering to pointed and curved distal tips. Gubernaculum shoe-like, 45 – 52 % of spicule length, proximally pointed and arcuate, distal end provided with a large rectangular sleeve. Tail divisible into two parts, a short conoid part and a longer filamentous part. Genital sensilla nine pairs; three pairs precloacal and six pairs postcloacal. Genital sensilla formula: v 1, v 2, v 3 d / v 4, ad, (v 5, v 6, v 7), phasmids, pd. Precloacal pair v 1 located anterior to the spicular range, more than one cloacal body diameter anterior to cloaca; v 2 at the level of the spicule head; v 3 d about one cloacal body diameter anterior to cloaca; v 4 just posterior to cloacal aperture; v 5 – 7 clusters greatly separated from each other with left subventral group at the level of ad and right subventral group just anterior to pd. Phasmids pore-like, slightly posterior to left subventral v 5 – v 7 group, 1.3 – 1.8 anal body diameter posterior to cloacal opening.	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
038687B8FFE5FF84FE70FD94FB03FE73.taxon	discussion	Remarks The original description of D. monhysteroides was given by Bütschli (1874). The values of morphometric characters of D. monhysteroides of our sample overlap with those of Bütschli (1874). Our population also resembles the type population in the shape of lip region, structure of stoma, pharynx, position of nerve ring and shape and size of gubernaculum. However, it differs in shape of spicules and number and arrangement of genital papillae. Spicules in our specimen bear curved distal end (Fig. 14 I) while in the type population, they are smoothly arcuate with straight distal end. Bütschli (1874) mentions 12 pairs of genital papillae in which group v 5 – 7 was in two pairs. Both clusters of first pair are situated at the level of ad and both clusters of second pair just anterior to pd while in our population, only one pair of v 5 – 7 is evident. As clearly seen in the SEM images (Fig. 16 F, H), the two clusters are separated from each other. The discrepancy in numbers (12 pairs vs 9 pairs) appears to have arisen because of the anteriorposterior segregation of the cluster of v 5 – 7 group which may have resulted in the unusual configuration of the genital sensilla in the type population. Our population of D. monhysteroides resembles the closely related species D. cerea. However, it differs in position of amphids (at the base of dorsal tooth vs at the level of gymnostom), size of dorsal tooth (dagger-like vs medium-sized), subventral armature (small tooth on both walls vs small ridges on both walls), post-uterine sac (longer than vulval body diameter vs shorter than vulval body diameter), shape of spicules (curved distal end vs smoothly tapering to a distal end), shape of gubernaculum (shoe-like with rectangular sleeve vs keel-like, proximally notched without distal sleeve) and arrangement of genital sensilla (v 1 and v 2 closely placed; both cluster of v 5 – 7 at the same level vs v 2 far posterior to v 1, situated near cloaca; v 5 – 7 separated, first pair at the level of ad and second pair just anterior to pd). Bionomics The nineteen species of Diplogastrellus are distributed worldwide. Seven species have been recorded from Asia, six from Europe, three from North America, two from Oceania, and one from Africa. Most species, e. g., D. didelphis sp. nov., D. indicus, D. latigubernacula, D. longipharyngis sp. nov., D. robustus sp. nov., D. sikorai, and D. thoubalicus, have been described from India, whereas D. gracilis, D. monhysteroides, and D. stammeri have been reported from Germany, and D. cerea, D. metamasius, and D. prodelphis from the USA. The rest of the species, viz., D. graciloides, D. mikuschi, D. secundus, D. heynsi, D. parvus, and D. pulcher, were described from Russia, The Netherlands, Denmark, South Africa, Fiji, and New Guinea, respectively. The species of Diplogastrellus have been predominantly reported from farmyard manure, rotting banana rhizome, decaying cactus, decay leaves of Iris L., rotting barks, wet humus, soil, compost of mushroom as well as from frass of beetle. However, two species (D. metamasius and D. monhysteroides) were reported to be associated with insects. Diplogastrellus metamasius was phoretically associated with sugarcane weevil (Metamasius hemipterus), recovered as dauer from the abdominal intersegmental folds and grown on xenic culture of bacteria. Diplogastrellus monhysteroides isolated from genitalia of male and female beetles (Onthophagus taurus).	en	Mumtaz, Sabia, Bashir, Ishrat, Ahmad, Irfan, Tahseen, Qudsia (2025): New insights into Diplogastrellus Paramonov, 1952 (Nematoda: Rhabditida: Diplogastroidea) with three novel and three known species from India. European Journal of Taxonomy 1008: 1-50, DOI: 10.5852/ejt.2025.1008.3019, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3019/13535
