Pseudocheironchus ingluviosus Leduc 2013, gen. et sp. nov.
Creators: name: Leduc, Daniel
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Adenophorea
Desmodorida
Selachinematidae
Pseudocheironchus
Pseudocheironchus ingluviosus

description: Pseudocheironchus ingluviosus gen. et sp. nov.
Figs 4-7, Table 1
urn:lsid:zoobank.org:act: 258E6E4A-6142-4A49-88B9-9A6E9B765309
Diagnosis
Pseudocheironchus ingluviosus gen. et sp. nov. is characterised by mandibles, each with two pairs of four blunt hooks, mandibles joined by a membrane with slender cuticularised ridges at their junction, multispiral amphideal fovea with 5.0 turns, short conical tail with rounded end, and males with spicules 1.5-1.7 abd long and 17-19 cup-shaped pre-cloacal supplements.
Etymology
The species name comes from the Latin ingluviosus (= voracious, gluttonous), and refers to the welldeveloped feeding apparatus of the species.
Material examined
Holotype
NEW ZEALAND: ♂, NIWA 88356, 5 Apr. 2007, NIWA cruise TAN0705, station 38, western Chatham Rise crest, 43.8266° S, 176.7043° E, 478 m, medium sand (45.3%), fine sand (43.9%).
Paratypes
NEW ZEALAND: 1 ♀, NIWA 88357, 20 Feb. 2011, NIWA cruise TAN1103, station 69, central Chatham Rise, 43.331° S, 178.288° E, 350 m, sediment depth 1-5 cm, mean grain size 55-59 μm, 55-57% sand, particle sorting (geometric) 4.1-4.3. 1 ♂, 1 ♀, NIWA 88358, 5 Oct. 2001, NIWA cruise TAN0116, station U2582, Chatham Rise crest, 43.4333° S, 178.5000° E, 350 m, silt/clay (37.5%), fine sand (23.4%), medium sand (21.4%).
Description
Males
Body cylindrical, tapering slightly towards both extremities. Cuticle 1.5-1.8 μm thick throughout body, thicker in tail region, 3-4 μm, with transverse rows of punctations, without lateral differentiation or differentiation consisting of slightly larger punctations. Somatic setae short and sparse, in four sublateral rows. Head slightly set off by constriction at level of amphid. Six conical inner labial papillae; six small outer labial setae and four slightly longer cephalic setae (~ 0.1 cbd) situated in one circle. Amphideal fovea situated near anterior extremity, multispiral with 5.0 turns and transversely oval outline. Anterior portion of buccal cavity short, with six pairs of thin, cuticularised rhabdions fused proximally, ~ 6 μm long. Posterior buccal cavity with three equal mandibles, 18-21 μm long, with one mandible situated dorsally and two sub-ventrally. Each mandible consists of a heavily cuticularised axis with a longitudinal groove (Fig. 5A); axis is thinnest in middle portion and widens towards the posterior and anterior extremities; anterior portion consists of two sets of four blunt hooks; posterior extremity of axis rounded. Two thin membranes extend laterally from the entire length of each mandible (often difficult to observe); a thin, slightly bent, cuticularised ridge is found at the junction of the membranes, one situated ventrally and two sub-dorsally (Fig. 5A, B). Pharynx short, with conspicuous oval-shaped anterior bulb surrounding posterior portion of buccal cavity, 23 μm wide, 29 μm long, and rounded posterior bulb, 25 μm wide. Nerve ring at middle of pharynx. Secretory-excretory (S-E) system present, cellular body of ventral gland situated ~ 1.5 cbd posterior to pharynx, pore situated near posterior extremity of posterior pharyngeal bulb. Intestine cells with numerous round inclusions, most dense in cells immediately posterior to pharynx (Fig. 4A).
Reproductive system diorchic with short, ~ 50 μm long, outstretched testes. Anterior testis on left of intestine, posterior testis on right of intestine. Small, nucleated sperm cells, oval or elongated with pointed ends, ~ 6 × 2 μm. Spicules paired, curved, 1.5-1.7 abd long, widest in middle portion and tapering distally. Gubernaculum small, slightly bent, median part (cuneus) with hook-shaped projection pointing dorsally (Fig. 4F). Three, perhaps four pairs of ejaculatory glands situated anterior to spicules (Fig. 4E). Mid-ventral row of 17-19 cup-shaped pre-cloacal supplements, ~ 5 μm wide and 5 μm deep, situated 5-8 μm apart. Pre-cloacal supplements thickly cuticularised, with nerve entering anterior side of cup. No pre-cloacal seta observed. Post-cloacal setae/papillae not observed. Tail short, conical, with rounded posterior extremity and three small terminal setae. Three caudal glands and small spinneret present.
Females
Similar to males, but with smaller amphideal fovea with circular outline. Reproductive system didelphic-amphidelphic with reflexed ovaries. Anterior ovary on left of intestine, posterior ovary on right of intestine. Vulva located slightly pre-median. Vaginal glands present, pars proximalis vaginae surrounded by constrictor muscle.
description: Published as part of Leduc, Daniel, 2013, Two new genera and five new species of Selachinematidae (Nematoda, Chromadorida) from the continental slope of New Zealand, pp. 1-32 in European Journal of Taxonomy 63 on pages 11-14, DOI: 10.5852/ejt.2013.63, http://zenodo.org/record/3823012