Comesoma macramphida Yu & Wang, 2026, sp. nov.

Comesoma macramphida sp. nov. Figs 1, 2, 3, Table 1 Diagnosis. Comesoma macramphida sp. nov. is characterised by the following: outer labial sensilla setiform, buccal cavity cup-shaped with a cuticularized projection, amphidial fovea wide (77–92 % of the body diameter) and consisting of 2.5 turns, spicules L-shaped and with faint striation; gubernaculum short and boat-shaped, with a small caudally directed apophysis, 10 or 11 papilliform precloacal supplements and tail conico-cylindrical, with two long, terminal setae. Type material. Three males were measured and studied. Holotype: • ♂ on slide 22 WPK 10-3-13; paratype 1: • ♂ on slide 22 WPK 10-2-15; paratype 2: • ♂ on slide 22 WPK 10-3-2. Type locality and habitat. Rizhao coast, Shandong Province, China (35°26'N, 119°34'E). Specimens collected from sandy sediment at a depth of 0–2 cm; collected May 2022 by Wen Guo. Measurements. All morphometric measurement data are given in Table 1. Description. Males. Body cylindrical, slender, and long; anterior end truncated, and posterior end tapered. Cuticle punctated; punctations arranged in transverse rows throughout body; lateral differentiation with irregularly spaced larger punctations. Cephalic sensilla arranged in three circles of 6 + 6 + 4. Inner labial sensilla 6, papilliform. Outer labial sensilla 6, setiform, 0.55–0.6 head diameters in length. Cephalic setae 4, long, 2.1–3.0 head diameters in length. Cervical setae 8, 11–12 μm in length; somatic setae present in pharynx and caudal regions, 2–4 μm in length. Amphidial fovea spiral, with 2.5 turns, and wide, 77–92 % of body diameter, located immediately posterior to cephalic setae. Ocelli absent. Buccal cavity cup-shaped, 4 μm in depth, with subventral cuticularized projection at posterior. Pharynx muscular, cylindrical, and slightly expanded at posterior end but not forming true posterior bulb. Cardia conical, surrounded by intestine, and 7 μm in length. Nerve ring located in approximate middle of pharynx region, 48.9–52.2 % of pharynx length. Secretory excretory system present; secretory excretory pore 142–146 μm from anterior end. Renette cell oval, 31–41 μm in length, 14–20 μm in width, and 68–76 μm from pharynx posterior end. The reproductive system diorchic, with opposed and outstretched testes. Anterior testis to left of intestine and posterior testis to right. Spicules paired, L-shaped, with faint striation, 2.21–2.36 cloacal body diameters long. Gubernaculum boat-shaped, short, and parallel to distal end of spicules, and with a very small caudally directed apophysis. Precloacal supplements 10 or 11, papilliform; anteriormost precloacal supplement 133–171 μm from cloacal opening and posteriormost 10–14 μm from cloacal opening, respectively; distance slightly widening from posterior to anterior. Tail conico-cylindrical, 5.4–6.6 anal body diameters long, with cylindrical part about 1 / 3 of total length. Two terminal setae present, 16–17 μm in length. Four caudal glands in line with separate outlet. Female not observed. Etymology. The species epithet macramphida is derived from Latin macro (large) and amphida (amphidial) and refers to the large size of amphidial fovea. Differential diagnosis and discussion. Comesoma macramphida sp. nov. can be differentiated from other species by the combination of having spicules shorter than 100 μm and six outer labial sensilla setiform. The new species is similar to C. bermudense, C. hermani, C. minimum, C. quattuordecimsupplementata, C. sinica, C. stenocephalum, and C. tenuispiculum in amphidial fovea turns. This new species differs from C. bermudense in the length of the outer labial setae (6 μm vs 2 μm), ornamentation and length of spicules (59–64 μm, with faint striation vs 150–194 μm, without striation), gubernaculum length (11–14 μm vs 25 μm), and number of precloacal supplements (10–11 vs 18–22). Comesoma macramphida sp. nov. differs from C. hermani in the length of the body (2753–2933 μm vs 1694–2108 μm), length of the cephalic setae (23–30 μm vs 13 μm), spicule length (59–64 μm vs 169–184 μm), and length of the gubernaculum (11–14 μm vs 20–25 um). Comesoma macramphida sp. nov. differs from C. minimum in the length of the body (2753–2933 μm vs 1370–1520 μm), length of the cephalic setae (2.1–3.0 head diameters vs 1.1 head diameters) and spicule length (2.2–2.4 anal body diameters vs 6.3 anal body diameters) (Xiao and Guo 2023). Comesoma macramphida sp. nov. differs from C. quattuordecimsupplementata in the shape of the buccal cavity (cup-shaped, wide and with cuticularized projection vs cup-shaped and small, without a projection), length of cephalic setae (23–30 μm vs 9–10 μm), spicule length (59–64 μm vs 120–128 μm), and number of precloacal supplements (10–11 vs 14). Comesoma macramphida sp. nov. differs from C. sinica in spicule length (59–64 μm vs 166–179 μm) and number of precloacal supplements (10–11 vs> 20); the new species differs from C. stenocephalum in the length of the body (2753–2933 μm vs 4600 μm), depth of the buccal cavity (4 μm vs 8 μm), spicule length (59–64 μm vs 165 μm), and length of the gubernaculum (11–14 μm vs 40 μm). Comesoma macramphida sp. nov. differs from C. tenuispiculum in the length of the body (2753–2933 μm vs 1600 μm), the length of the cephalic setae (2.1–3.0 head diameters vs 1.5 head diameters), spicule length (59–64 μm vs 112 μm), and tail length (5.4–6.6 anal body diameters vs 3.5 anal body diameters, measured according to Filipjev 1918).