Paragnomoxyala breviseta Jiang & Huang, 2015, sp. nov.
Creators: name: Jiang, Weijun
name: Huang, Yong
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Adenophorea
Monhysterida
Xyalidae
Paragnomoxyala
Paragnomoxyala breviseta

description: Paragnomoxyala breviseta sp. nov.
(Fig. 2–3)
Type material. Holotype: ♂1 on slide DH12-812-1; paratypes: ♂2, ♂3, ♂4, ♂5, ♂6, ♀1, ♀2, ♀3, ♀4 and ♀5 on slides DH12-812-1, DH12-812-2, DH12-815-4, DH12-817-2, DH12-817-5 and DH12-817-6 respectively.
Type locality and habitat. Sublittoral in the East China Sea. Station DH8–1: 26º 46´N, 120º 50΄ E, water depth 51 m, muddy with a little sand sediment fraction.
Etymology. The species name refers to the short cephalic setae.
Measurements Table 1.
Characters Holotype Paratypes Description. Male. Body slender, gradually tapering towards terminal ends. Cuticle finely striated, arising at base of buccal cavity and ending at tail tip. Lips very high. Internal labial sensilla not visible, outer labial setae absent. Only four short cephalic setae, 3–4 µm long. Sub-cephalic setae absent. Buccal cavity large, funnel-shaped with cuticularized walls and extended anteriorly, lacking teeth, not surrounded by pharyngeal tissue, 11–26 µm deep (1.6–1.8 hd long), 5–11 µm wide (63–79% of cbd) in its middle; without teeth. Amphidial fovea circular, 4–9 µm µm in diameter (50% of cbd), situated at level of base of buccal cavity. Secretory-excretory system not visible. Pharynx cylindrical, slightly expanded towards the base, not formed into bulb. Cardia well developed, conical, 5– 12 µm long. Nerve ring at 45–46% of pharyngeal length. Tail tapering with distal third cylindrical, 5–6.3 abd long, with a short spinneret and three terminal setae. Some caudal setae scattered at suberventral sides of tail. Three caudal glands in a string.
male cloacal region, showing spicule and caudal glands. Scales: A, B, C, D=20 µm.
Testis not visible. Spicules almost straight with slightly curved proximal and distal ends, 15–30 µm long. Gubernaculum and precloacal supplements absent.
Females. Similar to males in most respects. Reproductive system monodelphic with an anterior outstretched ovary located left of the intestine and extending to pharynx base. Vulva with slightly raised lips, located at post-mid body length (66–69% of body length from the anterior end). Post-vulval uterine sac oval in shape, 40 µm long, packed with rounded sperms.
Diagnosis and discussion. Paragnomoxyala breviseta sp. nov. is characterized by having high lips; a large funnel-shaped buccal cavity with cuticularized walls and extended anteriorly; four cephalic setae 3–4 µm long; circular amphids 6–9 µm in diameter; spicules straight but slightly bent at both ends; absence of gubernaculum and procloacal supplements. Paragnomoxyala breviseta sp. nov. is the only one species found in the genus so far. The size of individuals is variable. Body length varies from 720 µm to 1100 µm, and the maximum body diameter varies from 21 µm to 55 µm. Discovery of Paragnomoxyala gen. nov. further proves that Xyalidae is a diverse and widespread family. Establishment of the new genus is significant for study of the feeding habits of each genus of Xyalidae and their system evolution. Paragnomoxyala gen. nov. is the genus with the largest buccal cavity in family Xyalidae found at present. It is potentially able to ingest foods of a wider size range including diatoms and small nematodes.
description: Published as part of Jiang, Weijun & Huang, Yong, 2015, Paragnomoxyala gen. nov. (Xyalidae, Monhysterida, Nematoda) from the East China Sea, pp. 467-474 in Zootaxa 4039 (3) on pages 470-473, DOI: 10.11646/zootaxa.4039.3.6, http://zenodo.org/record/242858