Pararhyssocolpus, Elshishka, Milka, Lazarova, Stela, Radoslavov, Georgi, Hristov, Petar & Peneva, Vlada K., 2015

Elshishka, Milka, Lazarova, Stela, Radoslavov, Georgi, Hristov, Petar & Peneva, Vlada K., 2015, New data on two remarkable Antarctic species Amblydorylaimusisokaryon (Loof, 1975) Andrassy, 1998 and Pararhyssocolpusparadoxus (Loof, 1975), gen. n., comb. n. (Nematoda, Dorylaimida), ZooKeys 511, pp. 25-68 : 40-41

Taxon classification Animalia Dorylaimida Pararhyssocolpidae

Pararhyssocolpus gen. n.

Diagnosis.

With characters of the family.

Relationships.

On the basis of main characters, this genus/family appears close to family Nordiidae , Qudsianematidae (subfamily Qudsianematinae Jairajpuri, 1965) and Dorylaimidae . The new family differs from the first family in pharynx widening at the middle of neck vs pharynx widening behind the middle of the neck, the pharyngeal expansion shape (somewhat “bibulbar”, with narrower middle part vs cylindrical), ventromedian supplements contiguous vs mostly spaced (except Lenonchium Siddiqi, 1965, it differs from the new family by its longer and filiform tail). From subfamily Qudsianematinae, Pararhyssocolpidae fam. n. can be differentiated by its double vs single guiding ring and labial papillae arrangement (small vs larger distance between inner labial papillae), indistinct vs distinct aperture of odontostyle. Also, the new family differs from fam. Dorylaimidae in odontostyle aperture (indistinct vs distinct) and especially in its characteristic postembryonic development pattern - J1 with long tail, c’ decreasing in successive stages and adults caused by the increasing of anal diameter rather than shortening of tail, adults with similar tail shape - conical with distal third much narrower, finger-like vs one or more juvenile stages bearing long (filiform or conical elongated) caudal region, adults with similar (either long or short and rounded, never conical) or dissimilar (long in females, short and rounded, ex ceptionally conical, in males) tail ( Peña-Santiago and Álvarez-Ortega 2014). Recent studies based on molecular data ( Holterman et al. 2008; Pedram et al. 2011; Álvarez-Ortega et al. 2013a, c; Peña-Santiago et al. 2015) show that the current classification of superfamily Dorylaimoidea is questionable with most families being not monophyletic taxa, as some of the genera are closer to members of other families. Further integrative studies are needed to clarify its phylogeny and systematics and to understand which characters are homologous and which are the results of convergent or parallel evolution ( Vinciguerra et al. 2014).

Distribution.

This species (genus, family) is endemic in Maritime Antarctic, having been recorded from many islands: Signy ( Loof 1975; Maslen 1979; 1981), Coronation, Elephant, Intercurrence, Galindez, Blaiklock, Limpet ( Loof 1975; Maslen 1979), Guébriant ( Maslen 1979), Adelaide ( Maslen and Convey 2006; Newsham et al. 2006), Anchorage, Leonie ( Maslen and Convey 2006), Livingston ( Peneva et al. 2009), Francis ( Velasco-Castrillón and Stevens 2014) and King George Islands ( Kito 2009; Russell et al. 2014). This is the first report of the species from Nelson Island.