Spirinia verecunda Leduc & Verschelde 2015, sp. nov.
Creators: name: Leduc, Daniel
name: Verschelde, Dominick
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Adenophorea
Desmodorida
Desmodoridae
Spirinia
Spirinia verecunda

description: Spirinia verecunda sp. nov.
urn:lsid:zoobank.org:act: 83F4CF38-29CF-4540-B05D-2245120A489B
Figs 1–3; Table 1
Diagnosis
Spirinia verecunda sp. nov. is characterised by a short, stout body, cuticle covered in minute hair-like structures, unispiral amphideal aperture and cryptospiral amphideal fovea, buccal cavity with a small dorsal tooth and minute subventral teeth, eight elongated glands surrounding the anterior portion of the pharynx, large sperm cells, spicules with weak capitulum, and absence of precloacal supplements.
Type material
Holotype
NEW ZEALAND: ♂, NIWA 88379, 20 Feb. 2011, NIWA cruise TAN1103, station 69, central Chatham Rise, 43.331° S, 178.288° E, 350 m.
Paratypes
NEW ZEALAND: 2 ♀♀, NIWA 88380, same data as holotype.
Etymology
The species name is derived from the Latin word verecundus (bashful, shy, coy), in reference to the anterior part of the head region deeply folded inwards.
Description
Male
Body stout, cylindrical, pale orange colour, tapering slightly towards both ends. Annulated cuticle, no lateral differentiation; annulations 0.6–0.8 µm apart; cuticle slightly thicker in pharyngeal region than elsewhere (2.2–2.5 vs 1.6–2.0 µm). Cuticle covered with dense layer of minute hair-like structures from posterior to amphid to near tail tip (barely visible under light microscope; Fig. 3 A–B); larger, 1 × 5 µm bacteria-like structures with narrow base also attached in pharyngeal region (Fig. 1D). A single protist, 74 µm long and 18 µm wide attached subdorsally near cloaca (Fig. 3E). Short somatic setae arranged in eight longitudinal rows along entire body length.
Blunt, slightly rounded annulated head region with annulations completely surrounding amphid (Fig. 1 A–B). Four cephalic setae near anterior edge of amphid; inner and outer labial sensillae not observed because labial region is folded inwards from level of cephalic setae. Cryptospiral amphideal fovea with slightly cuticularised outline and unispiral amphideal aperture (Fig. 3 A–B).
Buccal cavity with slightly cuticularised dorsal tooth and minute subventral teeth. Eight elongated glands, 12–17 µm in length, distributed around anterior portion of pharynx just posterior to buccal cavity (Figs 1 C–D, 3C). Pharynx muscular, oval-shaped posterior pharyngeal bulb, lumen not cuticularised. Nerve ring at 40–50% of pharynx length. Secretory-excretory system not observed. Cardia 10–12 µm long.
Reproductive system monorchic, with relatively large, outstretched testis situated to the left of intestine. Mature sperm large, globular to elongated in shape, up to 16 µm in length. Short, arcuate spicules with weak capitulum and tapering distally; velum present (Fig. 1G). Gubernaculum with cuneus broadest in middle portion and tapering proximally and distally; poorly developed lateral crurae (Fig. 1H). Precloacal supplements not observed. Tail conical, with two pairs of short subventral setae and one pair of subdorsal setae; three caudal glands restricted to tail region and spinneret present.
Female
Similar to male, but with wider body. One specimen bears a single protist (suctorian) on tail. Reproductive system didelphic, amphidelphic with reflected ovaries situated either both on the right or both on the left of intestine. Vulva located slightly post median. Cuticular pars distalis vaginae and pars proximalis vaginae surrounded by constrictor muscle.
Remarks
Spirinia verecunda sp. nov. shows similarities with several Spirinia and Chromaspirina species, i.e., Spirinia guanabarensis comb. nov., S. inaurita comb. nov., S. okemwai comb. nov., S. parma comb. nov., Chromaspirina chabaudi, and C. multipapillata. Of these, S. verecunda sp. nov. resembles S. okemwai comb. nov. the most in cuticle ornamentation (annulated head region, cuticle with minute hairlike structures), size and shape of the amphids, presence of large sperm cells, and absence of precloacal supplements. S. verecunda sp. nov. differs from the latter in having shorter body length (667–757 vs 966–1425 µm), lower values of a (17–22 vs 22–27), shorter cephalic setae (2 vs 3–6 µm), shorter spicules (38 vs 41–50), and shorter gubernaculum (13 vs 19–25). S. verecunda sp. nov. also differs from S. okemwai comb. nov. in the presence of elongated glands in the anterior region of the pharynx (absent in S. okemwai comb. nov.) and the structure of the gubernaculum (hook absent vs dorsally directed proximal hook). S. verecunda sp. nov. can most readily be distinguished from S. inaurita comb. nov. and S. parma comb. nov. by the size of the amphids (in males: 35% cbd in S. vercunda sp. nov. vs> 60% cbd in S. inaurita comb. nov. and S. parma comb. nov.), from Chromaspirina chabaudi by the structure of the gubernaculum (not surrounding spicules in S. verecunda sp. nov. vs surrounding spicules distally in C. chabaudi), from C. multipapillata by the absence of precloacal supplements (present in C. multipapillata), and from S. guanabarensis comb. nov. by its small body size (<800 µm in S. verecunda sp. nov. vs> 1800 µm in S. guanabarensis comb. nov.) and low values of a (17–22 vs 30–48).
description: Published as part of Leduc, Daniel & Verschelde, Dominick, 2015, New Spirinia and Stygodesmodora species (Nematoda, Spiriniinae) from the Southwest Pacific, and a revision of the related genera Spirinia, Chromaspirina and Perspiria, pp. 1-25 in European Journal of Taxonomy 118 on pages 10-14, DOI: 10.5852/ejt.2015.118, http://zenodo.org/record/3779432