A novel free-living endomyxan flagellate Viscidocauda repens gen. Nov., sp. nov

Abstract

Endomyxa comprises a diverse group of protists, including free-living amoebae and parasites, that infect various hosts. In this study, we report a new free-living amoeboflagellate, Viscidocauda repens gen. Nov., sp. nov., isolated from seawater near Hachijojima Island, Japan. V. repens is a gliding bacterivorous biflagellate and occasionally extends pseudopodia from its posterior end. Molecular phylogenetic analysis based on small subunit ribosomal RNA gene sequences places V. repens as sister lineage to a clade comprising the endomyxan Ascetosporea and Gromiidea. Ultrastructural observations revealed that V. repens has four microtubular roots (R1–R4), but lacks vp2, a unique microtubular band widely distributed among cercozoan flagellates. Based on its morphology, ultrastructure, and phylogenetic position, we propose V. repens as a new genus and species within Endomyxa.