Coccolithophores in the algal flora from South Urals (Russia) with the description of a new Hymenomonas species

Abstract

This paper focuses on the study of the diversity of coccolithophores in the reservoirs in the steppe zone of the South Urals (Russia). Four species of coccolithophores were identified in the studied reservoirs by scanning electron microscopy, namely Hymenomonas roseola, Jomonlithus littoralis, Chrysotila carterae and C. roscoffensis. Of these, H. roseola is registered in freshwater, J. littoralis—in the salinity range from 0.6 to 5.7‰, C. carterae and C. roscoffensis—at salinity 3.8–8.1‰. J. littoralis, C. carterae and C. roscoffensis are reported for the first time in Russia. A wide range of halotolerances of J. littoralis, C. carterae and C. roscoffensis is suggested. We noted morphological variability in the ornamentation of placoliths of C. roscoffensis. The description and microphotographs of unidentified coccoliths found in freshwater, which represent a species new to science, are also given.