taxonID	type	description	language	source
324E87DE693CFFAB867D2DD150BF8ECC.taxon	type_taxon	Type species Choanolaimus psammophilus de Man, 1880 (= Halichoanolaimus obtusicaudatus Shulz, 1934).	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE693CFFAB867D2DD150BF8ECC.taxon	diagnosis	Diagnosis (emended from Tchesunov 2014) All the anterior sensilla are papilliform. Cuticle is laterally differentiated with larger, more widely separated punctations. Spiral amphidial fovea with two or more turns. Rhabdions of the anterior cup-shaped buccal chamber posteriorly bicuspid. Pharynx cylindrical or with weak posterior bulb. Intestine blind; anus absent. Precloacal supplements are papilla pierced by fine pores. Tail very short, rounded conical or semicircular.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE693CFFAB867D2DD150BF8ECC.taxon	discussion	Remarks The type species of the genus occurs in dunes (“ about roots of beach spermatophytes ”; de Man 1880: 50) and estuarine environments (Riemann 1966). Halichoanolaimus obtusicaudatus Schulz, 1934 was synonymised with Choanolaimus psammophilus by Gerlach (1964). The diagnosis is emended to reflect the blind intestine and the absence of the anus in representatives of this genus.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE693CFFA586702FA056098D16.taxon	description	urn: lsid: zoobank. org: act: A 9649261 - CB 22 - 4 A 83 - 80 EA- 32 AC 1 DD 3839 A Figs 2 – 4; Tables 2 – 3	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE693CFFA586702FA056098D16.taxon	diagnosis	Diagnosis Body length 1321 – 1688 µm, cephalic region with slight constriction at level of amphids, amphidial fovea large, 0.51 – 0.56 cbd wide and with 4 – 5 turns, short pharynx with posterior bulb, each side of body with two to three groups of 8 – 11 dorsosublateral pore complexes arranged in longitudinal rows and located between pharyngeal and tail regions, spicule length 1.2 – 1.6 body diameters at level of cloacal opening, gubernaculum 36 µm long, three or four precloacal supplements, tail short and rounded, 0.7 body diameters long at level of cloacal opening in males. Differential diagnosis The new species is most readily distinguished from Choanolaimus psammophilus by the large amphidial fovea 0.51 – 0.56 cbd wide with 4 – 5 turns (vs amphidial fovea <0.3 cbd wide with 2 – 2 ¼ turns in C. psammophilus), arrangement of pore complexes (dorsosublateral vs dorso- and ventrosublateral in C. psammophilus), shape of the inner labial sensilla (papilliform vs ‘ flap-like’ or on swollen lobes in C. psammophilus), short 125 – 155 µm long pharynx with posterior bulb (vs pharynx> 200 µm long without posterior bulb in C. psammophilus), longer spicules (1.1 – 1.6 vs <1.0 body diameters at cloacal opening in C. psammophilus) and fewer precloacal supplements (3 – 4 vs 6 – 7 in C. psammophilus). Choanolaimus serieporus sp. nov. can be distinguished from C. sparsiporus sp. nov. by the slightly longer body (1321 – 1682 vs 1272 µm in C. sparsiporus), lower a ratio (17 – 18 vs 24 in C. sparsiporus), higher b and c ratios (11 and 32 – 38 vs 8 and 27, respectively, in C. sparsiporus), arrangement of pore complexes (groups of 8 – 11 pore complexes vs sparsely distributed in C. sparsiporus), and number of precloacal supplements (3 – 4 vs 2 in C. sparsiporus).	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE693CFFA586702FA056098D16.taxon	etymology	Etymology The species name is derived from the Latin ‘ series ’ (= ‘ row, succession’) and ‘ porus ’ (= ‘ hole’) and refers to the arrangement of the pore complexes in rows in this species.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE693CFFA586702FA056098D16.taxon	materials_examined	Type material examined Holotype NEW ZEALAND • ♂; Otago Fan complex, Papanui Canyon; 45.8668 ° S, 171.0415 ° E; 680 m water depth; 9 Feb. 2024; sandy mud sediments; voyage TAN 2402, stn 2; NIWA 181629. Paratypes NEW ZEALAND • 1 ♂; Otago Fan complex, continental slope; 46.9320 ° S, 171.7847 ° E; 1338 m water depth; 14 Mar. 2019; voyage TAN 1902, stn 130; NIWA 181630 • 1 ♀; Challenger Plateau, continental slope; 30.6450 ° S, 172.1533 ° E; 266 m water depth; 7 Jun. 2007; voyage TAN 0707, stn 134; NIWA 181631. Type habitat and locality Continental slope, New Zealand.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE693CFFA586702FA056098D16.taxon	description	Description Males Body cylindrical, tapering slightly towards both extremities, mostly colourless except for light brown intestine wall. Cuticle 3 – 4 µm thick, with faint annulations ca 2.0 – 2.5 µm apart; transverse rows of cuticle punctations with lateral differentiation consisting of larger, more widely spaced punctations beginning from about middle of pharynx length to proximal portion of tail. On each side of body, two to three groups of 8 – 11 dorsosublateral pore complexes arranged in longitudinal rows and located between pharyngeal and tail regions; each pore complex ca 1.5 – 2.5 µm in diameter. Somatic setae short, ca 2 µm long, sparse, irregularly arranged along body. Cephalic region slightly rounded, with slight constriction at level of amphids. Lip region short, slightly raised. Six inner labial papillae; six short outer labial papillae, ca 1.5 – 3.0 µm long, at same level as four cephalic papillae of same length. Amphidial fovea large, multispiral with 4 ¾ – 5 turns, situated ca 0.4 cbd from anterior end. Buccal cavity (pharyngostome) large, divided into anterior (gymnostome) and posterior portions (stegostome). Anterior portion of buccal cavity cup-shaped, 16 – 26 µm deep, with three sets of three cuticularised rhabdions, 14 – 21 µm long, terminating in three sets of small bifid teeth (denticles), with raised central denticle located in middle of each set; posterior portion of buccal cavity narrower, cylindrical, surrounded by three Y-shaped pairs of cuticularised rhabdions with swollen bases, of similar length to anterior rhabdions. Pharynx short, muscular, slightly swollen anteriorly and with posterior bulb; pharyngeal lumen not conspicuously cuticularised. Nerve ring near middle of pharynx length. Secretory-excretory system present; renette cell situated at level of cardia, ampulla small, pore situated immediately posterior to nerve ring. Cardia small, ca 6 µm long, partially surrounded by intestine. Posterior extremity of intestine blind, rectum absent. Reproductive system diorchic with opposed, outstretched testes. Anterior testis to the right of intestine, posterior testis to the left or ventrally relative to intestine. Sperm cells globular; in holotype, sperm cells of similar dimensions in both anterior and posterior testes (10 – 11 × 13 – 15 µm). In paratype, sperm cells markedly larger in anterior testis (14 – 16 × 17 – 24 µm) relative to posterior testis (6 × 10 µm). Spicules paired, curved, tapering distally, length 1.2 – 1.6 body diameters at level of cloacal opening; gubernaculum consisting of two detached lateral pieces (crurae) tapering distally, ca 0.4 spicule length, median portion of gubernaculum (corpus and cuneus) apparently absent. Three or four precloacal supplements present, consisting of raised areas of cuticle; posteriormost supplement 11 – 12 µm from cloaca, remaining supplements 8 – 13 µm apart. Tail short, rounded, cuticle gradually doubling in thickness posteriorly, reaching 7 µm thick distally; a few short and sparse somatic setae present. Three caudal glands located posterior to cloacal opening, spinneret present. Female Similar to males but amphids with 4 turns. Reproductive system didelphic-amphidelphic, with reflexed ovaries; anterior ovary to the right of intestine, posterior ovary to the left of intestine. Vulva situated near mid-body. Proximal portion of vagina surrounded by constrictor muscle, vaginal glands present. Intestine blind, anus absent.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6932FFA386782C6C577D8FD2.taxon	description	urn: lsid: zoobank. org: act: A 926 DC 8 A- 6 F 55 - 4 D 7 B-A 79 A-AE 31 E 6 FF 5 C 14 Fig. 5; Tables 2 – 3	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6932FFA386782C6C577D8FD2.taxon	diagnosis	Diagnosis Body length 1272 µm, large amphidial fovea, 0.56 cbd wide and with 5 ¼ turns, pharynx with posterior bulb, two dorsosublateral rows of small pore complexes sparsely distributed between pharyngeal and tail regions, spicule length ca 1.5 body diameters at level of cloacal opening, gubernaculum 24 µm long, two papilliform precloacal supplements, tail short, conical, 1.1 body diameters long at level of cloacal opening. Differential diagnosis The new species is most readily distinguished from Choanolaimus psammophilus by the large amphidial fovea 0.56 cbd wide with 5 ¼ turns (vs amphidial fovea <0.3 cbd wide with 2 – 2 ¼ turns in C. psammophilus), arrangement of pore complexes (dorsosublateral vs dorso- and ventrosublateral in C. psammophilus), shape of the inner labial sensilla (papilliform vs ‘ flap-like’ or on swollen lobes in C. psammophilus), pharynx with posterior bulb (vs pharynx without posterior bulb in C. psammophilus), longer spicules (1.5 vs <1.0 body diameters at cloacal opening in C. psammophilus) and fewer precloacal supplements (2 vs 6 – 7 in C. psammophilus). Choanolaimus sparsiporus sp. nov. can be distinguished from C. serieporus sp. nov. by the slightly shorter body (1272 vs 1321 – 1682 µm in C. serieporus), higher a ratio (24 vs 17 – 18 in C. serieporus), lower b and c ratios (8 and 27 vs 11 and 32 – 38, respectively, in C. serieporus), arrangement of pore complexes (sparsely distributed vs groups of 8 – 11 pore complexes in C. serieporus), and number of precloacal supplements (two vs 3 – 4 in C. serieporus).	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6932FFA386782C6C577D8FD2.taxon	etymology	Etymology The species name is derived from the Latin ‘ sparsus ’ (= ‘ few, rare, scattered’) and ‘ porus ’ (= ‘ hole’) and refers to the scattered arrangement of the pore complexes in this species.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6932FFA386782C6C577D8FD2.taxon	materials_examined	Type material examined Holotype NEW ZEALAND • ♂; Otago Fan complex, continental slope; 46.4971 ° S, 170.8644 ° E; 992 m water depth; 13 Feb. 2024; voyage TAN 2402, stn 34; NIWA 181632. Type habitat and locality Continental slope, New Zealand.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6932FFA386782C6C577D8FD2.taxon	description	Description Male Body cylindrical, tapering slightly towards both extremities, mostly colourless except for light brown intestine wall. Cuticle 3.0 – 3.5 µm thick, without annulations; transverse rows of cuticle punctations with lateral differentiation consisting of larger, more widely spaced punctations beginning from posterior to amphids to tail region. Two dorsosublateral rows of small pore complexes sparsely distributed between pharyngeal and tail regions; each pore complex ca 1.5 µm in diameter. Somatic setae short, 2.0 – 2.5 µm long, sparse, located dorsosublaterally and ventrosublaterally. Cephalic region somewhat rounded; lip region short, bearing six inner labial papillae. Six short outer labial papillae located slightly further posteriorly, ca 1.5 – 2.0 µm long, at same level as four cephalic papillae of same length. Amphidial fovea large, multispiral with 5 ¼ turns, situated ca 0.3 cbd from anterior end. Buccal cavity (pharyngostome) large, divided into anterior (gymnostome) and posterior portions (stegostome). Anterior portion of buccal cavity cup-shaped, 13 µm deep, with three sets of three cuticularised rhabdions, 11 µm long, terminating in three sets of small bifid teeth (denticles), with raised central denticle located in middle of each set; posterior portion of buccal cavity narrower, cylindrical, surrounded by three Y-shaped pairs of cuticularised rhabdions with swollen bases, 14 µm long. Pharynx muscular, slightly swollen anteriorly and with posterior bulb; pharyngeal lumen not conspicuously cuticularised. Nerve ring near middle of pharynx length. Secretory-excretory system present; renette cell situated at level of cardia, pore situated slightly posterior to nerve ring. Cardia small, partially surrounded by intestine. Posterior extremity of intestine blind, rectum absent. Reproductive system diorchic with opposed, outstretched testes. Anterior testis to the right of intestine, posterior testis to the left of intestine. Sperm cells spherical to globular, larger in anterior testis (11 × 11 – 14 µm) relative to posterior testis (6 × 6 µm). Spicules paired, curved, tapering distally, length 1.5 body diameters at level of cloacal opening; gubernaculum consisting of two detached lateral pieces (crurae) tapering distally, ca 0.4 spicule length, median portion of gubernaculum (corpus and cuneus) apparently absent. Two precloacal supplements present, consisting of small papillae on swollen portion of cuticle and connected to a hypodermal gland; posteriormost supplement 17 µm from cloaca, supplements 7 µm apart. Tail short, conical, rounded distally, cuticle gradually doubling in thickness posteriorly, reaching 10 µm thick distally; a few short and sparse somatic setae present. Three caudal glands, one of which extends well anterior to cloacal opening; spinneret present.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFA186692858551C8D51.taxon	type_taxon	Type species Gammanema ferox Cobb, 1920.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFA186692858551C8D51.taxon	diagnosis	Diagnosis (from Tchesunov et al. 2020) Cuticle with homogenous annulations, without longitudinal ridges or lateral differentiation. Six inner and six outer labial sensilla, either setose or papillose; four cephalic setae, often slender and longer; outer labial and cephalic sensilla often combined in common circle of 10, with dorso- and ventrosublateral sensilla arranged in four pairs with cephalic sensilla. Amphidial fovea spiral or loop-shaped, usually noticeably larger in males than in females. Somatic setae in irregular longitudinal rows; anterior cervical setae may be as long as cephalic setae. Mouth opening surrounded by partly fused lips shaping a circumoral membrane with fine longitudinal striation. Twelve projections, from small and inconspicuous to prominent and elaborate, at rim of mouth opening. Buccal cavity (pharyngostome) with two chambers, anterior cup-shaped and posterior cylindrical; walls of each chamber strengthened with three cuticularized rhabdions; rhabdions of anterior chamber terminate posteriorly in minute denticles. Pharynx cylindroids, evenly muscular and devoid of terminal bulb. Alimentary tract terminates by rectum and anus. Precloacal midventral supplementary organs sucker-like, cup-shaped, tubular, or absent. Tail short, conical, cuticle of its terminal cone levigated or smooth.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFA186692858551C8D51.taxon	discussion	Remarks The genus was revised by Tchesunov et al. (2020), who also provided a pictorial key to valid species. Prior to this study, 14 species were considered valid, while three (G. ferox Cobb, 1920, G. menzelii (Ditlevsen, 1918) Gerlach, 1964 and G. rapax (Ssaweljev, 1912) Gerlach 1964) are considered species inquirendae (Tchesunov et al. 2020). Gammanema rapax was considered as dubious by Murphy (1965) because the original description lacks illustrations and type specimens are evidently lacking. This decision was ignored or overlooked in some subsequent taxonomic publications (e. g., Platt & Warwick 1988; Okhlopkov 2002; Ahmed et al. 2020) but was accepted in the recent review of Tchesunov et al. (2020).	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFBB865E2C29564B8B8A.taxon	description	urn: lsid: zoobank. org: act: C 3 ECA 296 - 29 FD- 4 B 93 - AAF 0 - 82 B 7 F 74356 FE Figs 6 – 8; Table 2	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFBB865E2C29564B8B8A.taxon	diagnosis	Diagnosis Gammanema lunatum sp. nov. is characterised by body length 754 – 1817 µm, cuticle with minute spines mostly visible in tail region, amphideal fovea large and loop-shaped in males and small and unispiral in females, inner and outer labial setae of similar length (2 – 4 µm), conical and on broad cuticle bases, cephalic setae 0.25 – 0.35 cbd long, spicules relatively short (length = 0.8 – 0.9 body diameter at level of cloacal opening), gubernaculum ca ⅔ of spicule length, six to ten sup-shaped precloacal supplements, vulva at almost ⅔ of body length from anterior extremity, tail length 1.3 – 1.6 cloacal / anal body diameters. Differential diagnosis The new species differs from most other species of the genus, except Gammanema agglutinans Leduc, 2013, in males having loop-shaped amphidial fovea instead of unispiral (G. conicauda Gerlach, 1953) or multispiral amphidial fovea (all other species of Gammanema). The new species also differs in the shape of the amphidial fovea in females, which is multispiral in all other species of the genus for which observations are available, except G. conicauda which is characterised by the unispiral amphidial fovea. In addition, the new species differs from most congeners, except G. agglutinans, in having minute cuticular spines. Gammanema lunatum sp. nov. differs from G. agglutinans in the shape of the amphidial fovea in males (¾ vs ½ turn in G. agglutinans) and females (1.0 vs 1.5 turns in G. agglutinans), larger amphidial fovea size in males (17 vs 10 µm wide in G. agglutinans) and females (8 vs 5 µm in G. agglutinans), and the shape of precloacal supplements (cup-shaped vs tubular in G. agglutinans). Gammanema lunatum differs from G. conicauda in the shorter body (754 – 1817 vs 1985 – 3724 µm in G. conicauda), markedly lower a ratio (13 – 16 vs 30 – 43 in G. conicauda), shorter outer labial setae (2 – 4 vs 16 µm in G. conicauda), shorter cephalic setae (8 – 20 vs 30 – 33 µm in G. conicauda), and fewer precloacal supplements (6 – 10 cup-shaped supplements vs 22 papilliform precloacal supplement in G. conicauda).	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFBB865E2C29564B8B8A.taxon	etymology	Etymology The species name is derived from the Latin ‘ lunatus ’ (= ‘ shaped like a crescent moon’) and refers to characteristic shape of the amphids in males.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFBB865E2C29564B8B8A.taxon	materials_examined	Type material examined Holotype NEW ZEALAND • ♂; Otago Fan complex, Papanui Canyon; 45.8668 ° S, 171.0415 ° E; 680 m water depth; 9 Feb. 2024; sandy mud sediments; voyage TAN 2402, stn 2; NIWA 181633. Paratypes NEW ZEALAND • 1 ♂, 1 ♀; same data as for holotype; NIWA 181634. Type habitat and locality Upper continental slope, New Zealand.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
324E87DE6936FFBB865E2C29564B8B8A.taxon	description	Description Males Body cylindrical, relatively stout, tapering slightly towards both extremities; no colouration except for light to dark brown intestine wall. Cuticle ca 2 – 3 µm thick, with faint transverse annulations ca 1 µm apart and transverse rows of punctations without lateral differentiation; minute spines visible mainly in tail region, may be present in mid-body region and apparently absent in pharyngeal region. Eight longitudinal rows of somatic setae, 4 – 7 µm long in pharyngeal and tail regions, 2 – 4 µm long in mid-body region; pore complexes not observed. Cephalic region blunt, slightly rounded. Mouth opening surrounded by 12 membranous projections of varying shape located in internal circle surrounded by the lips. Partly fused lips each bearing a conical inner labial seta, 2 – 4 µm long, on a broad cuticle base. Six outer labial setae of same size and shape located further posteriorly at base of lip region; four longer (ca 0.25 – 0.35 cbd long) and thinner cephalic setae located immediately posterior to outer labial setae, without broad base. Amphideal fovea relatively large, loop-shaped, situated slightly posterior to cephalic setae; amphidial aperture slightly shorter than amphidial fovea. Buccal cavity (pharyngostome) divided into anterior (gymnostome) and posterior portions (stegostome). Anterior portion of buccal cavity cup-shaped, ca 14 – 23 µm deep, with three sets of cuticularised rhabdions, 18 – 20 µm long, terminating posteriorly in pairs of small teeth or denticles; posterior portion of buccal cavity narrower, cylindrical, surrounded by three Y-shaped pairs of cuticularised rhabdions with swollen bases, of similar length to anterior rhabdions. Pharynx cylindrical, muscular, without anterior or posterior bulb; pharyngeal lumen not conspicuously cuticularized or partitioned. Nerve ring at ca 40 % of pharynx length from anterior. Secretory-excretory system not observed. Cardia small, surrounded by intestine. Intestine and vas deferens join posteriorly into cloaca, opening to the exterior via cloacal opening. Reproductive system diorchic with two short and opposed testes located ventrally relative to intestine; anterior testis outstretched, posterior testis reflexed. Sperm cells globular, longest diameter up to 23 µm, ca 1.5 – 2.0 greater than shortest diameter. Spicules paired, slightly curved, tapering distally, length 0.8 – 0.9 body diameters at level of cloacal opening; gubernaculum consisting of two flat detached lateral pieces (crurae), ca ⅔ of spicule length; median portion of gubernaculum (corpus and cuneus) apparently absent. Six to ten cup-shaped precloacal supplements; posteriormost supplement 18 – 32 µm anterior to cloacal opening, supplements located 5 – 17 µm apart. Tail short, conical; three caudal glands and spinneret present. Female Similar to males, except for conspicuously smaller, unispiral amphidial fovea and aperture. Reproductive system didelphic-amphidelphic, with reflexed ovaries located ventrally relative to intestine. Vulval opening on conspicuously swollen body region, situated almost two thirds of body length from anterior extremity. Proximal portion of vagina surrounded by constrictor muscle; several vaginal glands present surrounding vulval region. Rectum and anus present. Molecular phylogenetic relationships Partial SSU (526 bp) and near full-length D 2 – D 3 of LSU sequences (742 bp) were obtained for Gammanema lunatum sp. nov. and near full length SSU (1327 bp) and D 2 – D 3 of LSU sequences (710 bp) were obtained for Halichoanolaimus funestus. The Selachinematidae formed monophyletic clade in both the consensus SSU and D 2 – D 3 of LSU trees (Figs 9 – 10; 100 % posterior probability and bootstrap support). Two similar clades were recovered in both consensus trees: clade 1 comprised the genera Halichoanolaimus de Man, 1886, Bendiella Leduc, 2013, Cobbionema Filipjev, 1922 and Demonema Cob, 1894 with strong support (100 % posterior probability and 96 – 100 % bootstrap support), and clade 2 comprised the genera Gammanema, Latronema Wieser, 1954 and Choanolaimus with varying levels of support (95 – 100 % posterior probability and up to 75 % bootstrap support). The remaining genera (Choniolaimus Ditlevsen, 1918, Cheironchus Cobb, 1917, Pseudocheironchus Leduc, 2013, Synonchiella Cobb, 1933) formed a third clade in the D 2 – D 3 of LSU tree with moderate or no support (76 % posterior probability and <50 % bootstrap support), but not in the SSU tree. Gammanema lunatum formed a monophyletic clade together with the other Gammanema sequences in both SSU and D 2 – D 3 trees (100 % posterior probability and 99 – 100 % bootstrap support). We found no support for the monophyly of the genus Halichoanolaimus in either SSU or D 2 – D 3 of LSU trees; in the D 2 – D 3 of LSU tree, the Halichoanolaimus funestus Leduc, 2020 sequence was grouped together with Bendiella longicauda Leduc & Zhao, 2016.	en	Leduc, Daniel, Zhao, Zeng Qi (2025): Three new nematode species (Chromadorida: Selachinematidae) from the continental slope of New Zealand. European Journal of Taxonomy 989: 119-143, DOI: 10.5852/ejt.2025.989.2889, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2889/13099
