Mordukhovich V.V., Semenchenko A.A., Fadeeva N.P., Zograf J.K.
В журнале Progress in Oceanography
Год: 2019 Том: 178 Номер: 102160
Two nematode species of the subfamily Synonchinae Platonova, 1970, (Leptosomatidae Filipjev, 1916) were isolated during deep-sea expeditions to the Kurile-Kamchatka Trench and adjacent area, for morphological and molecular analyses. One new genus and two new species are described. Platonova gen. nov. differs from other known Synonchinae genera by the tail shape, by the pronounced division of pharyngostome into 2 parts, by the presence of one dorsal tooth in the anterior part of pharyngostome, by the presence of cuticular beams and microonchia in the posterior part of pharyngostome. Platonova magna sp.nov. is characterised by the combination of following characters: very large body size, cheilostome with three mandibular ridge, posterior part of pharyngostome with 6 cuticular beams 43–51 µm long, two ventrosublateral microonchia at about the level of the middle of the cuticular beams and dorsal microonchium at the base of cuticular beams, one ventral pre-cloacal supplement, spicules 214–243 μm, with wide vellum, capitulum with incision ending in circular fenestra. Platonova verecunda sp nov. is characterised by the combination of following characters: very large body size, cheilostome with three mandibular ridges, posterior part of pharyngostome with 6 cuticular beams 19–27 µm long, two ventrosublateral microonchia at the level of apical part of the cuticular beams and dorsal microonchium at the base of cuticular beams, one ventral pre-cloacal supplement, spicules 152–161 μm, with wide vellum, capitulum with circular fenestra. BI and ML phylogenetic analysis based on 18S and 28S rDNA suggest that Leptosomatidae requires transfer from superfamily Ironoidea (suborder Ironina) to superfamily Enoploidea (suborder Enoplina). Phylogenetic relationships within the family Leptosomatidae remained unresolved despite of the various sequences analysed in different loci. Finally, spatial distribution of the described species was analyzed.
