Terrestrial nematodes from the Galapagos Archipelago. 10. Morphological and taxonomical analysis of Carcharolaimus ramirezi Thorne, 1967 (Dorylaimida : Qudsianematidae)

Carcharolaimus ramirezi was found in six soil samples from four islands of the Galapagos Archipelago. It is described for the first time since its original discovery, with particular emphasis on the morphology of its anterior end as seen under light microscope and SEM. Six large, but thin, liplets overhang the labial basket, which consists of thick plates ornamented with irregular ridges and denticles. Posterior to the labial basket, six pillars form a postlabial cage and provide attachment for eight dilatatores buccae. The species can survive desiccation and is probably well adapted to and soils. Paratypes of C bediensis were also studied and revealed that this species is actually synonymous with C banaticus, rather than being very close to C. ramirezi as suggested by previous descriptions. The recently proposed genus Carcharodiscus is rejected, and the possible synonymy of Carcharolaimus with the senior genus Antholaimus is noted. A compendium to the genus Carcharolaimus is provided.