Minidiscus proschkinae (I.V. Makarova) J.S. Park & J.H. Lee in J.S. Park et al., PLoS ONE 2(9): 18. 2018.

Bilous, Olena P., Genkal, Sergey I., Zimmermann, Jonas, Kusber, Wolf-Henning & Jahn, Regine, 2021, Centric diatom diversity in the lower part of the Southern Bug river (Ukraine): the transitional zone at Mykolaiv city, PhytoKeys 178, pp. 31-69 : 31

Minidiscus proschkinae (I.V. Makarova) J.S. Park & J.H. Lee in J.S. Park et al., PLoS ONE 2(9): 18. 2018.

Basionym.

Thalassiosira proschkinae I.V. Makarova in Makarova, Genkal and Kuzmin, Bot. Zhurn. 64(7): 922, pl. 1, figs 1-7. 1979.

Morphological description.

The frustule is cylindrical, valve flat, diameter 3.8-4.9 μm, areolae polygonal, in quantities 25 in 10 μm, near centre of a valve, the central process and rimoportula are located (Figs 4H , 5A ).

Ecology.

This planktonic taxon has been mainly found in estuaries characterized by low salinity and high turbulence, and in seas, but also in freshwaters and may be a halophile indicator ( Makarova 1988; Park et al. 2017a; Barinova et al. 2019).

Distribution.

Valves were found in benthic samples in Mykolaiv city of the Southern Bug River and downriver (Table 1 ). For Ukrainian territory it was recorded for estuaries of the Black Sea and nearshore regions ( Tsarenko et al. 2009; Genkal and Terenko 2014).

Minidiscus proschkinae is widely distributed across estuaries and seacoasts of Europe (Germany, Great Britain, Netherlands, Russia, Ukraine), Asia (Azerbaijan, China), Argentina; Azov Sea, Baltic Sea, Caspian Sea ( Park et al. 2017a).

Figures

Figure 4. SEM (A, B and E-H) and LM (C, D) images of species found in the transitional zone at Mykolaiv city: A-D Pleurosira laevis A, C valve views with arrows shown the ocelli B girdle view E Conticribra weissflogii, valve view with arrows shown central and marginal fultoportulae F Thalassiosira incerta, valve view with arrow shown central fultoportulae G Thalassiosira faurii, valve view H Minidiscus proschkinae, valve view with arrow in the centre shown central fultoportula, and closer to the edge - rimoportula. Scale bars: 10 μm (C-G); 30 μm (A); 50 μm (B); 3 μm (H).

Figure 5. SEM images of species found in the transitional zone at Mykolaiv city (A, B, E-H valve views, C, D girdle views): A Minidiscus proschkinae with arrows showing rimoportula and marginal fultoportula B-D Skeletonema subsalsum with arrows showing marginal fultoportulae E Stephanodiscus hantzschii with arrow shown spines F Stephanodiscus makarovae with arrows showing marginal and central fultoportulae G, H Stephanodiscus minutulus with arrows showing spines and central fultoportula. Scale bars: 3 μm (A); 4 μm (B, F, H); 5 μm (C, D, G); 10 μm (E).