Biogeography and phylogenetic position of (Loof, 1975), gen. n., comb. n. from Maritime Antarctic (Nematoda, Nordiidae).

The taxonomic position of the endemic Antarctic species (Loof, 1975), , (= Loof, 1975) is discussed on the basis of morphological study, including SEM, morphometric data, postembryonic observations, and sequence data of 18S rDNA and the D2-D3 expansion fragments of the large subunit rDNA. A number of characters such as the cuticle and stoma structures, including the presence of moderately developed cuticularised ring around the oral aperture, peculiarities of pharynx expansion, size and position of the posterior pair of pharyngeal nuclei, a less complex uterus, and the position of a posterior ventromedian supplement show that this species differs substantially from the other members of the genus . Furthermore, both the 18S and 28S rDNA-based phylogenetic trees of the sequences available in the GenBank formed two distinct clusters with being a part of a well-supported group with species of the genus ; therefore, it is proposed that its taxonomic position should be reconsidered.