Macrolaimus richteri spec. nov. (Nematoda: Chambersiellidae) from the Richtersveld, South Africa

Abstract

Specimens of Macrolaimus richteri spec. nov. were examined with the aid of a scanning electron microscope (SEM) and some hitherto undescribed features of Macrolaimus were discovered. The sense organs are arranged in an inner circlet of six huge outer labial setae, a second circlet of four small cephalic setae and two pore-like amphid apertures in the first annule posterior to the head. The stomatal opening is surrounded by six flap-like lips covering the peculiar triangular cheilorhabdions which seem to be protmsible. The prominent anterior lip of the vulval opening is ornamented with about ten horizontal grooves. Distinctive characters ofM. richteri spec. nov. are the strongly annulated cuticle, slightly dorsad curved tail terminus and the length of the cheilorhabdions (1,6-1,8 times prorhabdion length).