Nullonchus rafiqi sp. n., a new mononchid species from West Bengal, India

Abstract

Nullonchus rafiqi, a new species of Mononchida from West Bengal, India, is described and illustrated. Nullonchus rafiqi sp. n. is characterized by a 2.7-2.9 mm long body, curved ventrally. Lip region offset from body; buccal cavity roomy, broad and flat, 56.6-60 × 33.3-36.3 μm; no dorsal or ventral tooth or denticle but two pairs of transverse ridges are found. Oesophago-intestinal junction tuberculate; genital system didelphic-amphidelphic with reflexed ovaries. Oesophagus cylindrical; tail elongated, five to six anal diameters long; caudal pores seven and caudal glands three in number; spinneret opening terminal. The new species can be distinguished from the other three species of the genus Nullonchus by the following combinations of characters: longer body and tail, larger buccal cavity, didelphic-amphidelphic genital system.