Marine Centrohelid Heliozoans (Centroplasthelida Febvre-Chevalier et Febvre, 1984) From Bays of Sevastopol (the Black Sea Shore)

Abstract

The species diversity and morphology of centrohelid heliozoans from the Black Sea shoreline (Southern Crimea) were studied with scanning and transmission electron microscopy to supplement our knowledge on the species composition and the features of the siliceous covering of centrohelids. Six species and forms (Acanthocystis trifurca, A. turfacea, Pterocystis foliacea, P. pontica sp. n., Raineriophrys fortesca, and Heterophrys-like organism) were found. Acanthocystis trifurca was the only species of centrohelids previously recorded in the Black Sea among observed heliozoans. The new species Pterocystis pontica sp. n. is described. Two variations of Acanthocystis turfacea cells, significantly different in the morphology of scales, were observed. Two species (Pterocystis foliacea and Raineriophrys fortesca) had an unusual morphology of scales and significantly differed from those most frequently encountered in literature.