%0 Journal Article
%T Two New Species of Centrohelid Heliozoans: Acanthocystis costata sp. nov. and Choanocystis symna sp. nov.
%A Zlatogursky, Vasily V.
%J Acta Protozoologica
%V 2014
%R 10.4467/16890027AP.14.021.1776
%N Volume 53, Issue 4
%P 313-324
%K Centrohelids, Heliozoa, protists, systematics, ultrastructure, external skeleton, Acanthocystis costata sp. nov., Choanocystis symna sp. nov.
%@ 0065-1583
%D 2014
%U https://ejournals.eu/en/journal/acta-protozoologica/article/two-new-species-of-centrohelid-heliozoans-acanthocystis-costata-sp-nov-and-choanocystis-symna-sp-nov
%X Two new species of centrohelid heliozoans Acanthocystis costata and Choanocystis symna from a freshwater lake on Valamo Island and a freshwater pool in St. Petersburg (North-Western Russia) were studied with light and electron microscopy. Sequences of 18S rDNA were obtained for both species.Choanocystis symna has dumbbell-shaped plate scales (4.4–5.0 × 1.62–1.90 µm) and spine scales (3.9–6.7 µm) bearing from 3 to 5 (usually four) short teeth on the distal end. Acanthocystis costata has oval plate scales (1.3–3.7 × 0.9–1.9 µm), bearing numerous granules as well as radial slits and spine scales (2.1–9.5 µm) with 4–6 teeth on the distal end. Acanthocystis costata and Acanthocystis nichollsi are similar in having slit-bearing plate scales and group together on the 18S rDNA tree. The presence of large particles of unknown nature was observed in food vacuoles of Acanthocystis costata.