Nematodes of the order Rhabditida from India.: Description of Sclerorhabditis tridentatus gen. n., sp n. (Nematoda: Rhabditidae)

A new rhabditid nematode, Sclerorhabditis tridentatus gen. n., sp. n. is described and illustrated. The body is small, less than 0.5 mm, and has an unusual labial and cephalic organisation. The dorsal and ventral lips have strongly sclerotised tridentate structures with the free ends of the forks directed towards the stoma, and the anterior margins of the lateral lips are sclerotised. An unusual feature of this species is the contour of the cephalic border that has axillae-like structures on the lateral sides. The stoma is wide and lacks a glottoid apparatus. The females are amphidelphic with reflexed ovaries and elongate conoid tails. Males were not found. The new genus resembles Diploscapter and the related genus Carinoscapter in having membranous lateral lips, absence of glottoid apparatus and amphidelphic reproductive system, but is clearly distinguishable by the shape and orientation of the sclerotisation of the dorsal and ventral lips and by the presence of a cephalic border.