Apart from a few studies on freshwater oomycetes, the ability of stramenopiles to turgor regulate has not been investigated. In this study, turgor regulation and growth were compared in two species of the stramenopile alga Vaucheria, Vaucheria erythrospora isolated from an estuarine habitat, and Vaucheria repens isolated

from a freshwater habitat. Species were identified using their rbcL sequences and respective morphologies. Using a single cell pressure probe to directly measure turgor in Vaucheria after hyperosmotic shock, V. erythrospora was found to recover turgor after a larger shock than V. repens. Threshold shock values for this ability were >0.5 MPa for V. erythrospora and <0.5 MPa for V. repens. Recovery was more Ruxolitinib in vivo rapid in V. erythrospora than V. repens after comparable shocks. Turgor recovery in V. erythrospora was inhibited by Gd3+ and TEA, suggesting a role for mechanosensitive channels, nonselective cation channels, and K+ channels in the process. Growth studies showed that V. erythrospora was able to grow over a wider range of NaCl concentrations. These responses may underlie the ability of V. erythrospora to survive in an estuarine habitat and restrict V. repens to freshwater. The fact that both species can turgor regulate may indicate a fundamental difference between members

of the Stramenopila, MAPK inhibitor as research to date on oomycetes suggests they are unable to turgor regulate. ”
“Euglena sanguinea (Ehrenberg 1831) was one of the first green euglenoid species described in the literature. At first, the species aroused the interest of researchers mainly due to the blood-red color of its cells, which, as it later turned out, is not a constant

feature. Complicated chloroplast morphology, labeled by Pringsheim as the “peculiar chromatophore system”, made the correct identification of the species difficult, which is the reason why, throughout the 20th century, new species resembling E. sanguinea MCE were continually being named due to a lack of suitable diagnostic features to distinguish E. sanguinea. Interest in E. sanguinea has returned in recent years, following findings that the species can produce ichthyotoxins. This was followed by the need to classify E. sanguinea correctly, which was achieved through the verification of morphological and molecular data for all species similar to E. sanguinea. As the result of the analysis, the number of species sharing some morphological similarities with E. sanguinea could be reduced from 12, as described in the literature, to four, with established epitypes and updated diagnostic descriptions. The most important diagnostic features included: the presence of mucocysts (i.e., whether they were visible before and/or after staining), the number of chloroplasts, the size of the double-sheathed pyrenoids, and the presence of the large paramylon grain in the vicinity of the stigma.