Pseudochromadora crispata Meng & Wang, 2026, sp. nov.

Pseudochromadora crispata sp. nov. Figs 1, 2, 3, Table 3 Type material. Four males and three females were collected from Station RCHW in May 2024. Holotype: m # 1 on slide number 24 RCHW 8-1-54, paratypes: m # 2 24 RCHW 8-1-204, m # 3 24 RCHW 8-1-52, m # 4 24 RCHW 8-1-38 and f # 1 on 24 RCHW 8-2-72, f # 2 on 24 RCHW 8-1-200, f # 3 on 24 RCHW 8-1-12. Type locality and habitat. All specimens were collected from the Yancheng coast, Jiangsu Province, China. 33°2'N, 120°51'E (RCHW), 0–8 cm sediment depth, sandy sediment. Etymology. The specific name refers to the nematode always being curled when fixed with formalin. Measurement. All measurement data can be found in Table 3. Description. Male. Body short, stout, with slightly golden brown colour. Cephalic capsule, the lip region forming a flattened hat on the main capsule region, rectangular shaped, 13–15 µm * 22–26 µm, a sutura present seperating capsule and lip region. Cuticle annulated starting just posterior to cephalic capsule. Lateral alae 5–8 µm wide, extending from pharynx posterior end to posterior to cloacal. Six inner labial sensillae and six outer sensilla setiform, 3 µm in length, located on lip region, four cephalic setae, 4–5 µm in length located just posterior to the labial region of cephalic capsule. Eight longitudinal rows of somatic setae, 2–4 µm in length. Amphidial fovea unispiral (30–36 % c. b. d.), situated at the main position of cephalic capsule, 6–7 µm from anterior end. Buccal cavity strongly cuticularized with one large dorsal tooth and one small ventrosublateral tooth. Pharynx muscular, with obvious posterior bulb. Nerve ring inconspicuous, at 54–67 % of pharynx length. Secretory-excretory system and cardia not found. Reproductive system monorchic, one anterior testis outstretched located on the right or left of intestine. Spicules slightly curved with small capitulum, 1.4–1.6 cloacal diameters in length. Gubernaculum plate-shaped (0.76–1.0 cloacal body diameters) with a cuticularized triangle-shaped lateral piece. Four ventral precloacal copulatory thorns. A pair of ventro-lateral postcloacal thorns, 31–42 µm posterior to cloaca. Tail conical-cylindrical with very short conical portion, 61–76 % of tail length. Three caudal glands and spinneret present. Female. Similar to males in most respects except amphidial fovea smaller (29 % – 33 % c. b. d.). Reproductive system with two reflexed ovaries, located on right side of intestine. Vulva located at posterior portion of the body (51–52 % of the body length from the anterior end). Vagina surrounded by constrictor muscle. Thorns absent. Diagnosis. Pseudochromadora crispata sp. nov. is characterized by its short body, lateral alae extending from pharynx posterior end to cloacal region, unispiral amphidial fovea, pharynx with obvious posterior bulb, slightly curved spicules, gubernaculum plate shaped with cuticularized lateral piece, four ventral precloacal copulatory thorns and one pair of postcloacal thorns, tail conical-cylindrical with conical portion short. The new species differs from other species of Pseudochromadora in the gubernaculum with triangular lateral piece and copulatory thorn arrangement. Pseudochromadora crispata sp. nov. is similar to Pseudochromadora buccobulbosa Verschelde & Vincx, 1995, P. incubans Gourbault & Vincx, 1990, P. rossica Mordukhovich, Fadeeva, Semenchenko & Zograf, 2015 with respect to the shape of spicules, but differs from P. buccobulbosa in the buccal cavity (without peri-buccal bulb vs prominent peri-buccal bulb), precloacal copulatory thorns (four in the male, female without thorns vs twenty in the male, five to ten thorns in the female), postcloacal thorns (a pair of thorns in the male vs a ventral group of small thorns), and gubernaculum length (25–30 µm vs 13–18 µm) (Verschelde and Vincx 1995); differs from P. incubans in outer labial setae length (4–5 µm vs 1.5 µm, papilliform), precloacal thorns (four vs three small thorns), gubernaculum length (25–30 µm vs 18–20 µm), tail length (2.3–3.2 c. b. d. vs 3.2–3.8 c. b. d.) (Gourbault and Vincx 1990); differs from P. rossica in amphidial width (0.29–0.36 c. b. d. vs 0.19–0.27 c. b. d.), copulatory thorns (4 vs 8–10), and gubernaculum length (25–30 µm vs 15–17 µm) (Mordukhovich et al. 2015).