A new marine urostylid ciliate, Arcuseries minima sp. nov., was discovered in South Korea. Morphological observations and molecular phylogenetic analyses based on small subunit ribosomal DNA (18S rDNA) sequences were used to describe the new species. Arcuseries minima is most similar to A. scutellum among all   Arcuseries species, but differs in the following main characters: number of adoral membranelles (13–16 vs. 17 or 18), cortical granules (yellowish, clustered around cirri and dorsal bristles vs. colorless, irregularly scattered), number of macronuclear nodules (20–27 vs. 42–90), number of midventral cirri (5–10 vs. 12–14), and number  f transverse cirri (5 or 6 vs. 8). The new species and A. scutellum differ from A. petzi and A. warreni in having smaller body size (≤80 μm vs. ≥80 μm) and fewer cirri: left marginal (≤ 17 vs. ≥ 18) and transverse (≤ 8 vs. ≥8) cirri. This relationship was supported by the phylogenetic tree, where these two groups were separated into two branches.

The morphology and phylogenetic position of a haptorian ciliate, Phialina pupula (Müller, 1773) Foissner, 1983, isolated from microaerobic sandy sediments of the floodplain area of the Boise River, Idaho, U.S.A., were studied using live observation, protargol impregnation, scanning electron microscopy, and the 18S rRNA gene as  well as the ITS region. The Boise population of P. pupula is characterized by a size of about 60–130 × 20–50 μm, an elliptical macronucleus with a single micronucleus, highly refractive dumbbell-shaped inclusions scattered throughout the cytoplasm and concentrated in the anterior body half, a single subterminal/terminal  contractile vacuole, about 10 μm long rod-shaped extrusomes, and an average of 15 ciliary rows. In phylogenetic analyses, the newly obtained sequences from P. pupula and Lacrymaria olor clustered within the family Lacrymariidae with full to moderate statistical support. Neither the genus Phialina nor the genus Lacrymaria was depicted monophyletic both in the single gene and multigene phylogenetic inferences. Specifically, the genus Phialina was shown as a paraphyletic assemblage containing members of the polyphyletic genus Lacrymaria. This indicates that the phialinid bauplan, i.e., an anterior body end differentiated into a head-like structure  directly attached to the trunk, might represent the ground pattern in the family Lacrymariidae. On the other hand, the long highly contractile neck carrying the head-like structure probably evolved later and convergently in multiple Lacrymaria species from Phialina-like ancestors.

Three species of trichodinid ciliates, common parasites or symbionts of aquatic invertebrates and vertebrates, have been reported from pumpkinseed (Lepomis gibbosus, Centrarchidae) in both their native (Trichodina fultoni, T. tumefaciens) and introduced (T. fultoni, Trichodinella epizootica) ranges. In this study, we report five additional trichodinid taxa collected from invasive L. gibbosus in France and two regions of the Czech Republic. We describe a new species, Trichodina lepomi sp. n., recorded in L. gibbosus from both countries. The new species differs from T. nigra by absence of posterior projection of blade, absence of notch/ indentation  opposing ray apophysis, absence of ray apophysis and the blade not being displaced anteriorly relative to ray as significantly as in T. nigra. Two widely distributed species, identified as Trichodina acuta and T. cf. heterodentata, were observed on juvenile fish in the Dyje river basin (Czech Republic). Finally, two undescribed species  f Trichodina sp. and Tripartiella sp. are reported. Detailed description of the new species and comparison with other congeneric species are presented.

The protein profiles of the epimastigote stages from eight reference strains of Trypanosoma cruzi belonging to three different lineages (TcI, TcII and TcVI) were analyzed by SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis), under standardized conditions. More than 40 protein bands were observed in each strain. Around 55% of them were not shared by all stocks (non-conserved proteins), representing their intra-specific variability. Then, they were coded for processing by numerical taxonomy, using three association coefficients and the UPGMA clustering algorithm. With all coefficients assayed, two major groups were clearly seen, confirming the dichotomy within T. cruzi taxon, as demonstrated by other molecular and biochemical approaches. In the present study, the term peptideme was used to name the groups of strains based on their polypeptide profiles, following the above-cited methodology. Then, two major peptidemes were identified, each one presenting subdivisions. The isolates identified as TcI clustered in the same major peptideme, displaying a subgroup with the opossum isolates (G, SC28, Dm28c) apart from the stock of human origin (Colombian strain). The other major peptideme also showed two subgroups, regardless the coefficient used. One of them included  the TcII strains (Y, SF21), both from Brazilian patients, and the other the TcVI stocks, both originally from triatomines from Southern Brazil (CL Brener, FL). As far we know, this is the first report on the parity between the T. cruzi lineages consensually accepted and their grouping into peptidemes based on SDS-PAGE and the numerical analysis of non-conserved proteins.

The influence of extremely low-frequency electromagnetic fields (ELF-EMFs) on microorganisms has been a subject of experimental investigations with promising results. In the present study, it was demonstrated that 2.0 mT 60Hz ELF-EMFs inhibited Trypanosoma cruzi epimastigotes growth. In addition, no synergistic or  antagonistic parasite growth and viability effects were observed after cultures were co-exposed to magnetic fields and Nifurtimox, a well-known anti-trypanosome drug. Moreover, the current study represents the first report regarding direct magnetic fields effects on Trypanosomas.