En garde! Redefinition of <i>Nebela militaris</i> (Arcellinida, Hyalospheniidae) and erection of <i>Alabasta</i> gen. nov.

Molecular data have considerably contributed to building the taxonomy of protists. Recently, the systematics of Hyalospheniidae (Amoebozoa; Tubulinea; Arcellinida) has been widely revised, with implications extending to ecological, biogeographical and evolutionary investigations. Certain taxa, however, still have an uncertain phylogenetic position, including the common and conspicuous species <i>Nebela militaris</i>. A phylogenetic reconstruction of the Hyalospheniidae using partial sequences of the mitochondrial Cytochrome Oxidase Subunit 1 (COI) gene shows that <i>N. militaris</i> does not belong to genus <i>Nebela</i>, but should be placed in its own genus. The morphological singularities (strongly curved pseudostome and a marked notch in lateral view) and phylogenetic placement of our isolates motivated the creation of a new genus: <i>Alabasta</i> gen. nov. Based on their morphology, we include in this genus <i>Nebela kivuense</i> and <i>Nebela longicollis</i>. We discuss the position of genus <i>Alabasta</i> within Hyalospheniidae, and the species that could integrate this new genus based on their morphological characteristics.