Rhadinema Cobb, 1920

Holovachov, Oleksandr & Boström, Sven, 2014, Swedish Plectida (Nematoda). Part 5. Rhadinema timmi (Vitiello, 1971) comb. n., Zootaxa 3779 (4), pp. 477-486 : 484

Rhadinema Cobb, 1920

Diagnosis (emended after Holovachov & Boström, 2010). Cuticle annulated, annules smooth, without ornamentation. Lateral alae absent. Epidermal glands present, opening through the distinct body pores. Somatic setae present only on tail, not connected to epidermal glands. Labial region rounded, continuous with body contour, lips fused. First annulus at level of cephalic setae bases, cephalic capsule absent. Inner labial sensilla indistinct. Outer labial sensilla papilliform, located on anterior surface of lips. Cephalic sensilla setiform; their bases located at base of labial region. Subcephalic and cervical sensilla, deirid and ocelli absent. Amphidial fovea round. Secretory-excretory system: renette cell located along the ventral side of intestine; excretory pore located posterior to nerve ring; excretory canal weakly cuticularised, extending from pore for a short distance to the excretory ampulla. Oral opening pore-like. Buccal cavity funnel-shaped or tubular: cheilostom consists of a sclerotised ring with six cuticularised longitudinal rugae: one dorsal, one ventral and four sublateral in position; gymnostom barrelshaped, with parallel, bar-shaped rhabdia; stegostom conoid or tubular, with uniformly thickened lumen, undifferentiated. Radial tubes absent. Arrangement of pharyngeal gland orifices unclear. Pharynx cylindrical anteriorly, gradually widening posteriorly; muscularised with uniformly thickened lumen throughout, lacking valves and bulbs. Anterior cylindrical part of pharynx subdivided by breaks in muscular pharyngeal tissue into cylindrical procorpus, cylindrical metacorpus and narrow isthmus. Cardia embedded in intestine. Female reproductive system didelphic, amphidelphic; ovary branches reflexed antidromously; spermathecae axial; vulva equatorial; vagina straight; pars proximalis vaginae encircled by a single sphincter muscle; pars refringens vaginae absent. Male reproductive system diorchic; testes outstretched; spicules arcuate, with ovoid manubrium, conoid shaft; gubernaculum plate-like with caudal apophysis. Copulatory apparatus: 7–11 tubular supplements, precloacal sensillum present; two postcloacal sensilla; several caudal setae arranged in subventral and dorsosublateral rows. Tail conoid. Three caudal glands present, their nuclei are incaudal. Spinneret functional, not cuticularised.