Rare Species of Centric Diatom Algae (Bacillariophyta, Centrophyceae) from Ukraine

摘要

This article summarizes the results of a study on the benthos found in the lower part of the Southern Bug River. The study focuses on an ecotone site, where an increase in the taxa composition of salt-water species was recorded. The centric diatoms' species diversity was investigated based on the samples collected in 2017 at the following three sites of investigation: north of the Mykolaiv city ( approximately 5 km), directly in the city (Varvarivskyi Bridge), and 5 km south of the city. The study of this material allowed us to identify five rare Ukrainian species of centric diatom algae Actinocyclus normanii (W. Gregory ex Greville) Hustedt, Cyclotella cryptica Reimann, J.C. Lewin et Guillard, Cyclotella marina (Tanimura, Nagumo et M. Kato) Ake-Castillo, Okolodk. et Ector, Minidiscus proschkinae (I.V. Makarova) J.S. Park et J.H. Lee, and Stephanodiscus makarovae Genkal. The original microphotographs, obtained via a scanning electron microscopy (FE-SEM (Hitachi 810, ×1000) are included. The obtained data broaden our perspective in the ecology of this planktonic species, as well as supplement its morphological distinctive features. Findings of named representatives of centric diatom algae in the Southern Bug River contribute to advance information on the biodiversity of the river flora and its geographical distribution within the Ukraine.