Re-isolation and revaluation of boundaries of Thecamoeba terricola Greeff, 1886 (Amoebozoa, Discosea, Thecamoebida), with description of Thecamoeba vicaria n. sp.

We studied a large species of Thecamoeba found in a glass dish with soaked moss and obtained 18s rRNA gene sequence of this organism. Morphologically, the strain was most similar to T. terricola sensu Page, but had significant differences in cell size and nuclear morphology.

Thecamoeba vumurta n. sp. (Amoebozoa, Discosea, Thecamoebida) from freshwater pond sediment - a sibling species of T. striata (Penard, 1890) Schaeffer, 1926.

Until recently, it seemed that amoebae of the genus Thecamoeba could be reliably identified using light-microscopic characters. However, recent studies show the presence of sibling species in the genus Thecamoeba, which can only be reliably distinguished based on the molecular data. Here we describe a new freshwater species, Thecamoeba vumurta n.

New data on the fine structure of Deuteramoeba mycophaga CCAP 1586/1 (Amoebozoa, Tubulinea).

The genus Deuteramoeba is one of the six amoebae genera belonging to the best-known amoeba family - Amoebidae (Amoebozoa, Tubulinea), containing such a popular species as Amoeba proteus. However, members of other genera of the family Amoebidae are much less known, and most of the studies of their morphology and ultrastructure date back to the 1970s and 1980s. Since these "classical" species are believed to be "well studied", their morphology and fine structure rarely become a subject of re-investigation.

Polychaos centronucleolus n. sp. - a new terrestrial species of the genus Polychaos (Amoebozoa, Tubulinea) with nontypical nuclear structure.

A new species of the "proteus-type" naked amoebae (large cells with discrete tubular pseudopodia) was isolated from tree bark sample of a birch tree in the surrounding of Kislovodsk town, Russia and named Polychaos centronucleolus n. sp. (Amoebozoa, Tubulinea).

Molecular Phylogeny of Polychaos annulatum (Amoebozoa, Tubulinea, Euamoebida) Shows that Genus Polychaos Belongs to the Family Hartmannellidae.

We have obtained a sequence of the 18S rRNA gene of the species Polychaos annulatum (Penard 1902) Smirnov et Goodkov 1998 using the isolation of a single nucleus from an amoeba cell. Attempts to amplify the 18S rRNA gene from the DNA of this species by conventional PCR were not successful, so we applied the whole genome amplification of the nuclear DNA followed by NGS sequencing. The 18S rRNA gene was found among the resulting contigs.

Mitochondrial Genome of Vannella croatica (Amoebozoa, Discosea, Vannellida).

Mitochondrial genome sequence of Vannella croatica (Amoebozoa, Discosea, Vannellida) was obtained using pulse-field gel electrophoretic isolation of the circular mitochondrial DNA, followed by the next-generation sequencing. The mitochondrial DNA of this species has the length of 28,933 bp and contains 12 protein-coding genes, two ribosomal RNAs, and 16 transfer RNAs. Vannella croatica mitochondrial genome is relatively short compared to other known amoebozoan mitochondrial genomes but is rather gene-rich and contains significant number of open reading frames.

New data on the ultrastructure of Paradermamoeba levis (Amoebozoa, Discosea, Dermamoebida): Cytoplasmic MTOCs are found among Dermamoebida.

In this detailed electron microscopic study of Paradermamoeba levis Smirnov et Goodkov 1994 (phylum Amoebozoa, class Discosea, subclass Longamoebia, order Dermamoebida, family Dermamoebidae) based on numerous fixations and studies of a large number of cells we provide the first comprehensive description of the ultrastructure of this species. P. levis possesses cytoplasmic microtubule-organizing centres (MTOCs) associated with dictyosomes of the Golgi complex.