Microlaimus parakoreanus Meng & Wang, 2026, sp. nov.

Microlaimus parakoreanus sp. nov. Figs 4, 5, Table 4 Type material. Four males and three females were measured and studied. Holotype: m # 1 on slide 24 CJG-2-1-13; paratypes: m # 2 on 24 CJG-2-1-81, m # 3 on 24 CJG-2-1-80, m # 4 on 24 CJG-2-1-13, f # 1 on 24 CJG-2-1-44, f # 2 on 24 CJG-2-1-48, f # 3 on 24 CJG-2-1-76. Type locality and habitat. All specimens were collected from the Yancheng coast, Jiangsu Province, China. 34°15'N, 120°16'E (CJG), 0–2 cm sediment depth, sandy sediment. Etymology. The species name refers to the morphological character similar to Microlaimus korari. Measurement. All measurement data can be found in Table 4. Description. Male. Body spindle shaped. Cuticle striation from cephalic setae to tail tip. Head smooth. Six inner labial sensilla and six outer labial sensilla papilliform. Four cephalic sensilla papilliform. Somatic setae absent. Amphidial fovea cryptocircular, 42–55 % c. b. d., from anterior body end. Buccal cavity large, funnel-shaped, heavily cuticularised, with a large dorsal tooth and two small ventrosublateral teeth, small longitudinal cuticularized folds present in cheilostoma. Pharynx posterior portion widened into bulb. Nerve ring at 56–65 % of pharynx length. Secretory-excretory system present and excretory pore situated just posterior to nerve ring. Cardia not observed. Reproductive system paired, testes outstretched and opposed. Anterior and posterior testes to the right of intestine. Spicules curved and faintly cuticularized, proximal end swollen and distal end pointed. Gubernaculum heavily cuticularized, longer than spicules with distal end curving laterally and proximal end swollen. Precloacal supplements not observed. Tail conical with distal end slightly cylindrical. Three caudal glands and spinneret present. Females. Similar to males in most respects except amphidial fovea smaller (33 % – 42 % c. b. d.). Reproductive system didelphic and amphidelphic with two ovaries outstretched. Vulva located slightly posterior to mid-body. Vagina short and sclerotized. Diagnosis. Microlaimus parakoreanus sp. nov. is characterized by a striated cuticle, four papilliform cephalic setae, a buccal cavity with one large dorsal tooth and two small ventrosublateral teeth, amphidial fovea cryptocircular at level of posterior buccal cavity, absence of somatic setae, slightly curved spicules with swollen proximal end, heavily cuticularized gubernaculum, absence of precloacal supplements, conical tail with distal end slightly cylindrical. The genus Microlaimus was recently reviewed by Esteves et al. (2025), and 85 valid species were ascertained. The genus was seperated into seven groups based on spicule length, gubernaculum present or absent, cuticle ornamentation, distance from the anterior edge of amphidial fovea to the anterior end divided by the head diameter (Amph ant / hd). The new species belongs to group 4 B with Amph ant / hd ≤ 1 and amphids diameter