Centrohelids in the mires of Northern Russia

Abstract

SummaryThe species composition and morphology of centrohelid heliozoa collected from mire water bodies of different types in the North of the European part of Russia were studied. Eighteen species from five genera and four families, two species with an uncertain systematic position and some unidentified Heterophrys-like organisms were found (Arkhangelsk Region -9 species, Republic of Karelia -7, Vologda Region -9). Three species (Pterocystis paliformis, P. striata, P. tropica) are new for Russia. Nine species are new for Arkhangelsk Region (Acanthocystis penardi, A. trifurca, A. turfacea, Choanocystis symna, P. pinnata, P. tropica, Raineriophrys echinata, R. kilianii). Eight species are new to the centrohelid diversity of the Vologda Region (Acanthocystis lyra, A. aff. takahashii, A. trifurca, Polyplacocystis symmetrica, Pterocystis pinnata, P. tropica, Raphidiophrys intermedia). Four species are new for the Republic of Karelia (Pterocystis paliformis, P. striata, P. tropica, Raphidiophrys minuta). The species composition of the mires of the Arkhangelsk Region and the Vologda Region has much more in common in comparison with the centrohelid diversity of the Republic of Karelia. The most favourable conditions for the presence of high centrohelid species diversity occurred in the minerotrophic mires (15 species, incl. 5 -in mire streams, 7 -in space between hummocks, 9 -in flarks of the aapa mires), in comparison with the water bodies of ombrotrophic mires (4 species, incl. 2 -in laggs and 2 -in hollows of the raised bogs).

Centrohelid Heliozoans (Centroplasthelida Febvre-Chevalier et Febvre, 1984) from Different Types of Freshwater Bodies in the Middle Russian Forest-steppe

“…This species differs from A. polymorpha, A. siemensmae, A. valdiviense by the morphology of cup-shaped tips of short spine scales (Mikrjukov 2002). Morphology of observed scales corresponds to most known descriptions, except a different number of furcae in some papers: 2-3 in Siemensma and Roijackers (1988a), Leonov and Plotnikov (2009), Plotnikov and Ermolenko (2015), Prokina and Mylnikov (2019); 7-8 in Leonov (2010a), Prokina et al (2017c). Many authors noted a larger length of long spine scales -up to 15 µm (Leonov and Plotnikov 2009, Leonov 2010a, Mylnikov 2012, Plotnikov and.…”

“…Remarks: Morphology of observed scales is similar to previous descriptions. Some authors also observed pear-shaped plate scales (Leonov 2010a, Prokina et al 2017c. Croome (1983) and Nicholls (1986) described smaller diameter of the shaft (0.10-0.15 µm).…”

“…ceylanica] Dürrschmidt 1987a). It was found in Russia in freshwaters of European part (Mikrjukov 1993a, Leonov and Plotnikov 2009, Leonov 2010a, Leonov and Mylnikov 2012, Plotnikov and Ermolenko 2015, Prokina et al 2017c, in saline inland waters of Orenburg Region Ermolenko 2015, Plotnikov and. Wailes, 1925[syn.…”

“…Distribution: Freshwaters of Europe (Mikrjukov 1993b), Asia (Kosolapova and Mylnikov 2015), Africa (Prokina et al 2017b), N. America (Nicholls 1983), S. America (Dürrschmidt 1987a, Prokina andMylnikov 2019), Malaysia (Dürrschmidt 1987a). It was found in Russia in freshwaters of European part (Mikrjukov 1993a, Leonov 2009, Leonov and Plotnikov 2009, Leonov and Mylnikov 2012, Prokina et al 2017c.…”

“…Distribution: Freshwaters of N. America (Nicholls 1983), S. America (Dürrschmidt 1985), Australia (Croome 1986), Crimean Peninsula (Mikrjukov 1999). It was found in Russia in freshwaters of European part (Leonov and Plotnikov 2009, Leonov 2010a, Plotnikov and Ermolenko 2015, Prokina et al 2017c, in saline inland waters of Orenburg Region (Plotnikov and Gerasimova 2017), in the Black Sea (Leonov 2010a). 4E-G) Description: Diameter of protoplast of living cell is 29 µm.…”