More amoebae from the deep-sea: Two new marine species of Vexillifera (Amoebozoa, Dactylopodida) with notes on taxonomy of the genus

Two marine members of the genus Vexillifera Schaeffer, 1926 (Amoebozoa, Dactylopodida) are described. Vexillifera abyssalis n. sp. originates from an abyssal sample of the Western Atlantic 4.5 km deep, which is the first unambiguous record of a deep-sea Vexillifera. The second species, V. kereti n. sp. was isolated from the soft bottom sediments of the White Sea (depth 106 m). An analysis of available data on the genus Vexillifera shows that it comprises many different species, yet they are very unevenly studied. The majority of species have only been described using light microscopy, and their phylogenetic relationships with other amoebae are unclear. However, available small-subunit (SSU) rRNA gene sequences of Vexillifera spp. form a robust, yet very heterogeneous clade in the phylogenetic tree. These species demonstrate a wide range of morphological and ultrastructural characters and originate from diverse habitats, suggesting that Vexillifera may need to be subdivided into several genera in the future. In addition to the described species, we sequenced the COI gene of original CCAP strains of Vexillifera bacillipedes, V. minutissima and Pseudoparamoeba pagei, thereby performing a phylogenetic reconstruction of the Dactylopodida based on a decent taxonomic sampling.