Three Newly Recorded Species of the Family Mesorhabditidae (Nematoda: Rhabditida) in South Korea

The family Mesorhabditidae $Andr{\acute{a}}ssy$, 1976 is the most abundant group in Rhabditoidea and occurs all over the world. Over 85 valid species have been reported from Mesorhabditidae; however, only 2 species have been recorded in South Korea. In this study, Bursilla vernalis $Andr{\acute{a}}ssy$, 1982, Mesorhabditis inarimensis (Meyl, 1953) Dougherty, 1955, and M. minuta $Bostr{\ddot{o}}m$, 1991 belonging to the family Mesorhabditidae (Rhabditomorpha), are newly reported from South Korea. Species in this family are distinguished from other rhabditomorphs by a posteriorly located vulva and an unpaired prevulval female gonad. Details of the morphological characters and morphometrics of B. vernalis, M. inarimensis, and M. minuta are described and illustrated based on optical and/or scanning electron microscopy.