Megadraconema cornutum, a new subtidal genus and species from Korea, with a discussion of its classification and relationships within the family Draconematidae (Nematoda, Desmodorida) based on morphol

Abstract

A new genus and species of Draconematidae Filipjev, 1918, Megadraconema cornutum gen. n., sp. n., inhabiting subtidal detritus and coarse sediments in Jejudo, Korea is described. Megadraconema cornutum gen. n., sp. n. is mainly characterized by a long body (1630-2220 µm), presence of a transverse circle of well-developed papillae-like cuticular protrusions at the base of the lip region, a head capsule with reticular structure of subcuticle, a pore-like amphid opening and an internal, bar-shaped amphidial fovea. The diagnosis of the family Draconematidae is emended and a key to genus level is provided. Phylogenetic relationships, based on morphological features, are discussed and compared with results of molecular analyses. The phylogenetic position of the new genus and relationships within the family Draconematidae based on analysis of molecular sequence data are examined for the first time. Analysis of 18S rRNA gene sequences does not support the currently accepted classification, and indicates paraphyly of the subfamily Draconematinae.2