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The morphology, ciliary pattern and small subunit rDNA (SSU rDNA) sequences of two new cyrtophorian ciliates, Aegyria foissneri sp. n. and Lynchella minuta sp. n., isolated from brackish waters in southern China, were investigated. Aegyria foissneri sp. n. is characterized as follows: cell size 85–170 × 45–80 μm in vivo; body inverted oval with a protrusion and a dark pigment spot on anterior left part; 42–77 somatic kineties; one preoral and three to six circumoral kineties; five to eight transpodial segments; 31–44 nematodesmal rods; 12–16 contractile vacuoles; and single oval macronucleus. Lynchella minuta sp. n. is distinguished from its congeners by having a cell size of 20–30 × 15–20 μm in vivo, oval body outline; four preoral and 14 or 15 postoral kineties, three circumoral kineties; ca. 11 nematodesmal rods; one finger-like tentacle on the ventral side; and two diagonally located contractile vacuoles. Molecular phylogenetic analyses support the genus assignment of Aegyria foissneri sp. n. and indicate the monophyly of the genus. While Lynchella minuta sp. n. clusters with Coeloperix species, which indicates that Lynchella is non-monophyletic. [ABSTRACT FROM AUTHOR]

The living morphology and infraciliature of seven Dysteria species isolated from the seas around China were investigated by observation of both living cells and specimens after protargol impregnation. Dysteria paraprocera sp. n. is characterized as follows: cell size 110–150 × 30–40 μm in vivo; body elongate rectangular and slender; a yellow-brown to dark red coloured pigment spot located at anterior end of body; three right kineties, with rightmost two extending apically to dorsal margin and innermost one starting at level of cytostome; eight or nine short left kineties at equatorial area. Dysteria nabia , D. proraefrons , D. brasiliensis , D. cristata , D. derouxi and D. crassipes basically correspond well with previous studies and therefore only brief descriptions are presented. Discussions of these species are helpful, however, in understanding the circumscription of Dysteria morphotypes. After careful comparison, Dysteria procera sensu Liu et al. (2008, Acta Hydrobiol. Sin. 32 (suppl.), 84–89 (in Chinese with English abstract)) was verified as a new species, D. subtropica sp. n., mainly because the innermost right kinety starts at mid-body. Small-subunit (SSU) rRNA genes were sequenced for four species of Dysteria , namely, D. paraprocera sp. n., D. subtropica sp. n., D. proraefrons and D. nabia . Sequence comparisons and phylogenetic analyses indicate that these species are well outlined and cluster with their congeners. [ABSTRACT FROM AUTHOR]

The ciliophoran taxon Chonotrichia Wallengren, 1895 are epibionts typically on Crustacea. There are about 112 species reported from all around the world. These species are known essentially from microscopical observations, and molecular data are far from sufficient, which largely hinders the study on their phylogenetic relationships. Here, we present the complete small-subunit (SSU) rDNA sequences of three species from Roscoff, Brittany, France, and one from Switzerland. These sequences are used to analyze the phylogentic relationships of the Chonotrichia, covering all three controversial orders, Exogemmida Jankowski, 1972, Cryptogemmida Jankowski, 1975, and Chilodochonida Batisse, 1994, for the first time. The phylogenetic tree confirms that all chonotrich sequences group together, nested in the dysteriid sequences. The tree topology also shows the separation of the chilodochonids from Exogemmida, supporting the establishment of the order Chilodochonida. [ABSTRACT FROM AUTHOR]

We recently established a new species, Homalogastra binucleata , with a morphological description and phylogenetic analyses based on SSU rRNA gene sequence data (Liu et al., 2020). Helmut Berger (Salzburg, Austria) commented that Homalogastra binucleata Liu et al., 2020 is a junior primary homonym of H. binucleata Song, 1993, the latter having been transferred to the genus Uronemita by Liu et al. (2016). According to article 57.2 of the ICZN (1999), the junior primary homonym, Homalogastra binucleata Liu et al., 2020, is permanently invalid. It is replaced by Homalogastra similis nom. nov. [ABSTRACT FROM AUTHOR]

In the last two decades, cyrtophorian ciliates have been revealed to demonstrate a high species diversity. But this group remains difficult to study, mainly because of their low abundance and relatively few taxonomically informative morphological characters. As a contribution to the taxonomy of cyrtophorians, here we investigate three Dysteria species based on their live morphology, ciliary pattern, and molecular phylogeny. Dysteria ozakii nom. nov. can be recognized by its elongate body shape and four right kineties, including three frontoventral kineties. A neotype has to be fixed for the species as no type materials were deposited. The other two species, D. brasiliensis Faria et al., 1922 and D. compressa (Gourret & Roeser, 1886) Kahl, 1931, are redescribed and supplementary information for each is supplied. Phylogenetic analyses based on small-subunit (SSU) rRNA gene sequences support the validity of the species. In addition, four species of bacterial epibionts were observed on the surface of the three Dysteria spp. The identities of these bacterial species are discussed based on the newly obtained 16S rRNA gene sequences. [ABSTRACT FROM AUTHOR]

With highly specialized morphology and unexplored functional capacities, ciliates from extreme habitats are drawing increasing attention. During a microbial investigation of a solar saltern pond (salinity 240‰) on Mallorca, Spain, a previously unknown scuticociliate, Platynematum rossellomorai n. sp. was isolated, cultured and studied using a tripartite approach consisting of a morphological description, a molecular analysis and an ecophysiological characterization. The ciliate has distinct morphological characteristics and its main diagnostic features include a large anteriorly positioned oral area (occupying almost half of the body length), two caudal cilia and a small number of somatic kineties. However, due to the most important generic feature of Cinetochilidae, the consistency of the arrangement of the adoral membranes, the ciliate is classified as a new member of the genus Platynematum. Its 18S rRNA gene sequence shows a sequence similarity of 91.0% to the closest deposited relative, Platynematum salinarum , and a phylogenetic analysis reveals a close relationship to other members of the family Cinetochilidae Perty, 1852. Growth experiments identify the ciliate as a borderline halophile, with a tolerance range between 180 and 280‰ salinity. The ciliate apparently accumulates the compatible solutes glycine betaine and ectoine to counterbalance osmotic stress, however, other osmoregulatory mechanisms are not excluded. [ABSTRACT FROM AUTHOR]