A new eyeless species of Nicon (Annelida: Nereididae) from the deep Northwest Pacific Ocean

A new species of the nereidid annelid, genus Nicon Kinberg, 1866, from KIOST Seamount, Northwest Pacific deep water is described. Nicon is a genus characterized by lacking paragnaths or papillae on the pharynx and composed of nine species worldwide, distributed from shallow water to deep sea. Nicon ablepsia sp. nov. here described is characterized by the lack of eyes on the prostomium, prolonged tentacular cirri reaching to chaetiger 6, notochaetae homogomph spinigers, neurochaetae homogomph spinigers and heterogomph falcigers. Phylogenetic relationships of Nicon remain undetermined based on molecular data. In this study, we constructed molecular Maximum-Likelihood phylogenetic tree from 29 nereidid species based on four marker genes: mitochondrial 16S rRNA gene and cytochrome c oxidase subunit I (COI) gene; nuclear 18S rRNA gene and 28S rRNA gene. Our analysis suggested the Nicon was clustered within Nereidinae. Nereidinae was not recovered as monophyletic. A key to species of Nicon is provided.