Aegialoalaimus magnus Leduc 2023, sp. nov

Aegialoalaimus magnus sp. nov. urn:lsid:zoobank.org:act: 4D4BD1F6-70E8-4E2B-BF6C-530389C772AA Figs 13–15, Table 6 Diagnosis Aegialoalaimus magnus sp. nov. is characterized by body length 2.8–3.3 mm, papilliform cephalic sensilla, amphids with strongly cuticularized outline and central region with pitted appearance, radiating, cuticularized processes surrounding junction of pharyngostome and cheilostome, secretory-excretory pore located at or near level of nerve ring and ventral gland well posterior to cardia, spicules 1.4–1.6 cloacal body diameters long, well-developed gubernacular apophyses, 11–12 inconspicuous precloacal supplements, and conical tail 2.8–3.5 cloacal or anal body diameters long. Differential diagnosis The new species differs from all other species of the genus in the longer body (2.8–3.3 vs magnus ʼ meaning ʻlargeʼ, ʻgreatʼ and refers to the relatively large size of the species. Material examined Holotype NEW ZEALAND • ♂; Hikurangi Margin, Mungaroa cold seep site; 41.9376° S, 175.3110° E; 2075 m water depth; collected on 7 Jul. 2019; sandy mud sediment (97% silt/clay, mean particle size 19 µm), voyage TAN1904, station 18; NIWA154918. Paratypes NEW ZEALAND • 2 ♀ ♀; same collection data as for holotype; NIWA 154920 • 1 ♂; Glendhu cold seep site; 41.7695° S, 176.0882° E; 1993 m depth; collected 10 Jul. 2019; sandy mud sediment (88% silt/clay, mean particle size 27 µm), voyage TAN1904, station 40; NIWA 154919. Type habitat and locality New Zealand continental slope, Hikurangi Margin, Mungaroa and Glendhu cold seeps. Description Male Body colourless, cylindrical along most of its length, tapering slightly towards both extremities. Cuticle with fine transverse striations without lateral differentiation. Body pores and epidermal glands absent. A few sparse, short somatic papillae, 1 µm long, present in anterior pharyngeal region. Cephalic region slightly rounded; lip region poorly developed, continuous with body contour, lips fused. Inner labial papillae not observed; six short outer labial papillae, Female Similar to males, but with excretory pore located at or slightly anterior to level of nerve ring. Reproductive system didelphic with two opposed and reflexed ovaries both located ventrally or to the left of intestine; spermatheca absent. Vulva situated at mid-body. Proximal portion of vagina surrounded by constrictor muscle, small vaginal glands present. Uterus wall not cuticularized.
Published as part of Leduc, Daniel, 2023, New nematode species and genera (Nematoda: Chromadorea) from cold seeps on Hikurangi Margin, New Zealand, pp. 1-45 in European Journal of Taxonomy 856 on pages 29-34, DOI: 10.5852/ejt.2023.856.2025, http://zenodo.org/record/7522913