Genus

Revised diagnosis

(based on Fonseca and Bezerra 2014). Anterior sensilla in three circles of 6 + 6 + 4. Cuticle laterally differentiated, with transverse or longitudinal rows of punctations; lateral pore complex either absent or present. Posterior portion of buccal cavity conical, with three ridges; each ridge ending in an acute projection at border to anterior portion. Spicules curved. Gubernaculum with dorso-caudally directed apophysis. Precloacal supplements present, setiform or tubular.

Remarks.

The genus Paramesonchium was established with the P. seriale as its type species, which was transferred from genus Laimella based on the presence of longitudinal rows of coarse punctations on the cuticle and buccal cavity conoid shaped. Subsequently, additional species were described: P. belgicum Jensen, 1976, P. angelae (Inglis, 1968), and P. mombasi Muthumbi, Soetaert & Vincx, 1997. Zhang (1992) later transferred P. angelae to the genus Dorylaimopsis Ditlevsen, 1918.

The morphological characteristics of Paramesonchium exhibit considerable variation. Notably, P. seriale was described based on a female specimen and was characterised by being laterally differentiated and having the buccal cavity with three acute tips; P. belgicum was characterised by lacking cuticle differentiation and having a lateral pore complex present, a buccal cavity with three acutely pointed lips, and setiform precloacal supplements each with a duct. Paramesonchium mombasi was characterised by having a cuticle with differentiation, a buccal cavity lacking teeth, and setiform precloacal supplements. Based on current taxonomic understanding, Paramesonchium should encompass species in which the cuticle either has or lacks lateral differentiation, the lateral pore complex is present, and precloacal supplements are either setiform or tubular (as demonstrated below).