TY - JOUR AU - Davidovich, O. I. AU - Davidovich, N. A. AU - Podunay, Yu. A. AU - Solak, C. N. PY - 2022/06/07 Y2 - 2024/03/29 TI - Halotolerance limits of the Black Sea representative of the genus Entomoneis Ehrenberg, 1845 (Bacillariophyta) JF - Marine Biological Journal JA - mbj VL - 7 IS - 2 SE - Scientific communications DO - 10.21072/mbj.2022.07.2.03 UR - https://marine-biology.ru/mbj/article/view/337 SP - 32-40 AB - <p>The genus <em>Entomoneis</em> Ehrenberg, 1845 is quite rich in species. Underestimated diversity of this genus requires its deeper morphological and molecular study, as well as an investigation of ecological and physiological characteristics of its species – specifically, their tolerance limits to environmental factors. Considering the distribution of <em>Entomoneis</em> species in water bodies with various salinity, we aimed at studying the tolerance limits and determining optimal salinity for vegetative growth and sexual reproduction of the diatom <em>Entomoneis</em> sp. from the Black Sea. We used reproductively compatible clonal cultures isolated from samples taken on the Crimean and Turkish Black Sea coasts. For <em>Entomoneis</em> sp. clone 7.0906-D, the nucleotide sequence of the <em>rbc</em>L gene was obtained; it is presented in the GenBank database under the number MT424817. Morphologically, the studied species resembles <em>E. paludosa</em>; according to molecular data, it is far from it. In accordance with its ecological and physiological characteristics, this species is a marine one. According to published material available, <em>E. paludosa</em>, unlike <em>Entomoneis</em> sp., inhabits brackish, slightly saline, and even fresh water bodies. Experiments on halotolerance show the following: the Black Sea clones of <em>Entomoneis</em> sp. are viable in a range of at least 40 ‰ (8 to 48 ‰). A salinity range of the medium within which <em>Entomoneis</em> sp. revealed sexual reproduction is much narrower – 18 to 36 ‰. Optimal salinity values for vegetative growth and sexual reproduction were determined (27.4 and 26.4 ‰, respectively); those turned out to be higher in both cases than the values in the natural habitat of this species. As salinity of the medium increased, <em>Entomoneis</em> sp. initial cells resulting from sexual reproduction tended to decrease in size.</p> ER -