No abstract

With about 480 known species, Pilidiophora (phylum Nemertea) has been regarded as consisting of Hubrechtiiformes (~20 spp.) and Heteronemertea (~460 spp.). Most (~87%) of the latter belong to Lineidae (> 400 spp.), while the systematics of non-lineid heteronemerteans remains largely untouched. To explore the phylogeny of non-hubrechtiiformid, non-lineid pilidiophorans, we performed multilocus molecular phylogenetic analyses with five genes (18S, 28S, H3, 16S and COI) from 41 newly sequenced specimens. Pilidiophora comprised Hubrechtellidae, Lineidae, Valenciniidae, the new family Eopilidiidae and a not formally named family-level heteronemertean taxon. Eopilidion misakiense gen. et sp. nov. is described from a specimen from Japan, but whether it belongs to Heteronemertea remains unclear. Apart from this new species, the following 11 new species of valenciniids are established, based on molecular sequences and external morphology (localities in parentheses): Baseodiscus giribeti sp. nov. (Panama), B. kakuii sp. nov. (Japan), B. komatsui sp. nov. (Japan), B. narusei sp. nov. (Japan), B. ohtsukai sp. nov. (Japan), B. paracelensis sp. nov. (Vietnam), B. profundus sp. nov. (Russian Far East), B. urgorrii sp. nov. (Spain), B. zebra sp. nov. (Japan), Oxypolella hiebertae sp. nov. (Vietnam) and Valencinura jambio sp. nov. (Japan).

Remane (1927) established the generic name Xenotrichula for a single species of marine gastrotrich, Xenotrichula velox Remane, 1927. Recently, Hummon and Todaro (2010: 22–23) created the new subgenus Velox, designating X. velox as the type species, despite Article 44.1 of the International Code of Zoological Nomenclature (hereafter, the "Code") (ICZN 1999). Because the subgeneric names Xenotrichula Remane, 1927 and Velox Hummon & Todaro, 2010 share the same name-bearing type species, the latter is an objective junior synonym of the former and thus should be regarded as permanently invalid. Hence the nominotypical subgenus must be expressed as Xenotrichula (Xenotrichula) Remane, 1927, and its type species Xenotrichula (Xenotrichula) velox.