Melosira subglobosa (Grunow) Houk, Klee & Tanaka in Fottea 17 (Supplement):17, pl. 17, figs 1-10; Pl. 19, figs 1-15; pl. 19, figs 1-11. 2017.

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

Melosira subglobosa (Grunow) Houk, Klee & Tanaka in Fottea 17 (Supplement):17, pl. 17, figs 1-10; Pl. 19, figs 1-15; pl. 19, figs 1-11. 2017.

Synonyms.

Melosira borreri var. subglobosa Grunow, Melosira moniliformis var. subglobosa (Grunow) Hustedt.

Morphological description.

Frustule shape is cylindrical to approximately octagonal (Fig. 2A, F ). Valve 12.5-26 μm in diameter, mantle height 3.1-8.5 μm. Valve face nearly octagonal with flat tops (Fig. 2B-E, G ). Girdle with puncta forming straight and transverse rows 32-56 in 10 μm.

Ecology.

Marine and brackish, benthic-planktonic (tychoplanktonic) species, halophilic, widely distributed. Indicates significant organic pollution (eutrophication), α-mesosaprobiont ( Kolpacov et al. 2014). This species prefers water enriched with dissolved organic matter, and is capable to switch from autotrophic to heterotrophic or mixed type of nutrition ( Andreeva et al. 2008). Additionally, these diatoms are ubiquitous, and widely distributed in seas and estuaries of temperate zones in habitats with a moderate level with increased level of human impact ( Kuzminova and Rudneva 2005; Ryabushko 2009).

Distribution.

Melosira subglobosa is one of the most common species at the sampling sites near the Mykolaiv area in the Southern Bug River (Table 1 ). For Ukrainian territory, it is known from the coastal zone in the northwestern part of the Black Sea, Crimean seaboard, and some estuaries.

For a worldwide distribution, it was recorded from coastal zones of Europe, and Asia; specifically, from Lake Aral, Baltic, Bering, Black, Caspian, Mediterranean, North and Norway Seas ( Tsarenko et al. 2009).

Figures

Figure 2. SEM (A-D, H) and LM (E-G) images of species found in the transitional zone at Mykolaiv city: A-G Melosira subglobosa (A, F girdle views, B-E, G, valve views) H Melosira varians, partial valve view and girdle view of complete frustule. Scale bars: 10 μm (A-C, E-H); 20 μm (D).