A new and a known species of Xiphinema Cobb, 1913 (Dorylaimida: Xiphinematidae) from West Bengal, India with a key to the mono-opisthodelphic species of the genus

Abstract

Xiphinema manasiae sp. n. and X. americanum Cobb, 1913 sensu lato were collected from the soil around the roots of litchi at South 24-Parganas district, West Bengal, India. Xiphinema manasiae sp. n. is one of the species of this genus having a mono-opisthodelphic reproductive system with undifferentiated anterior uterine sac. The new species comes closer to X. chambersi Thorne, 1939, X. radicicola Goodey, 1936 and X. monohysterum Brown, 1968, having a mono-opisthodelphic reproductive system with or without anterior genital branch reduced to a uterine sac but with some distinctly different morphometric measurements (body shorter than X. chambersi and X. monohysterum, vulva more posterior than X. chambersi, ‘a’ less than in X. monohysterum and tail longer than X. radicicola with greater c/) and hence deserves to be proposed as a new species. It also differs from the closely related species in having a distinct anterior uterine sac, much shorter pre-rectum and different tail shape. This is also the first record of X. americanum sensu lato from the South 24-Parganas district of West Bengal. A diagnostic key of fourteen species of the genus with opisthodelphic gonad has been provided.