Morphology, taxonomy and distribution of the rare species Aulacoseira cataractarum (Hustedt) Simonsen (Bacillariophyta) in Russia

This scanning electron microscopy study was undertaken to reanalyze frustule samples of the centric diatom algae Aulacoseira cataractarum, collected earlier from a swamp in the Uzon volcanic caldera (Kamchatka). This species, under the name of Melosira cataractarum, was reported before from a number of waterbodies in Russia. Later it was transferred to the genus Aulacoseira Thwaites – A. cataractarum (Hustedt) Simonsen (Simonsen, 1979), and then – to the genus Pseudostaurosira (A.Grunow) D.M.Williams & F.E.Round, under the name of P. seudostaurosira cataractarum (Hustedt) Wetzel, Morales et Ector. In this study we specify perforation of intercalary bands, the shape of the valves and spines as well as the number of valve face and mantle areolae per stria and their shape. Based on the original and published data an extended diagnosis of P. cataractarum is presented. Scanning electron microscope images of frustules of the centric diatom algae.

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About a new representative of the genus Aulacoseira Thw. (Bacillariophyta) for the flora of Ukraine

Algologia ◽

10.15407/alg31.02.163 ◽

2021 ◽

Vol 31 (2) ◽

pp. 163-169

Author(s):

S.I. Genkal ◽

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Morphological Characteristics ◽

Diameter Ratio ◽

Published Data ◽

Centric Diatom ◽

Diatom Algae ◽

A New Species ◽

Microscopy Images ◽

Scanning Electron

In this study, scanning electron microscopy images of valves of the centric diatom algae Aulacoseira subborealis (Nygaard) Denys, Muylaert et Krammer from from the Kaniv Reservoir and the Desna River are analyzed. The quantitative (colony size, valve diameter and mantle height, the ratio of mantle height to valve diameter, number of areola rows and areolae in 10 µm on the mantle, ring-shaped diaphragm size) and qualitative (short pointed spines, areolae arrangement on the valve face and the mantle) morphological characteristics correspond to the diagnosis of A. pusilla (F.Meister) A.Tuji & A.Houki, a new species for the flora of Ukraine. In the analyzed material, minimum values of the mantle height and the height/diameter ratio are lower than in the published data.

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To morphology, ecology and distribution of rare species Sellaphora hustedtii (Krasske) Lange-Bertalot et Werum (Bacillariophyta) from waterbodies of the Gydan Peninsula

Novosti sistematiki nizshikh rastenii ◽

10.31111/nsnr/2014.48.57 ◽

2014 ◽

Vol 48 ◽

pp. 57-65 ◽

Cited By ~ 1

Author(s):

S. I. Genkal ◽

M. I. Jarushina

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

River Basin ◽

Rare Species ◽

Western Siberia ◽

Microscopy Study ◽

Electron Microscopy Study ◽

Diagnostic Features ◽

Scanning Electron Microscopy Study ◽

Scanning Electron

A rare species Sellaphora hustedtii, which is also new for the flora of Russia, has been found in waterbodies of the Messoyakha River basin (south-western part of the Gydan Peninsula, Western Siberia). The scanning electron microscopy study revealed variability of the main quantitative and qualitative diagnostic features of the species (length and width of the valve, number of striae and areolae in 10 μm, shape of the valve and structure of the raphe). New data on the ecology and distribution of the species allowed us to specify its diagnosis.

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