Aulacoseira nivalis (W. Sm.) J. English & Potapova, Proc. Acad. Nat. Sci. Philadelphia 158 (1): 39. 2009.

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

Aulacoseira nivalis (W. Sm.) J. English & Potapova, Proc. Acad. Nat. Sci. Philadelphia 158 (1): 39. 2009.

Basionym.

Melosira nivalis W. Sm. Syn. Brit. Diat. 2, p. 58, pl. LIII, fig. 336. 1856.

Synonyms.

Melosira distans var. nivalis (W. Sm.) O. Kirchner, Aulacoseira distans var. nivalis (W. Sm.) E.Y. Haworth.

Morphological description.

Cells cylindrical, valve face flat, 7.5-12.8 μm in diameter, valve mantle 3.8-4.7 μm high. Valve face with rough areolae, located in intersecting diagonal rows (Fig. 3B ).

Ecology.

This is a freshwater species, found growing in or near snow and in alpine pools ( Houk et al. 2007; English and Potapova 2009) but was also reported for alkaline and acid waters ( Kulikovskiy et al. 2016).

Distribution.

At the localities of upstream Mykolaiv, in Mykolaiv City and downstream Mykolaiv Aulacoseira nivalis is the first record for Ukraine (Table 1 ).

As for other countries, it is known from alpine and northern regions ( Krammer and Lange-Bertalot 2000); frequently occurring in western North America ( English and Potapova 2009) and as being abundant in lake sediments in Brazil.

Figures

Figure 3. LM (A, B) and SEM (C-H) images of species found in the transitional zone at Mykolaiv city: A Aulacoseira islandica, valve view B Aulacoseira nivalis, valve view C Aulacoseira subarctica, girdle view of complete frustule D-H Actinocyclus normanii valve view (D pseudonodulus shown with arrow, E, G) and girdle view (H, F). Scale bars: 10 μm.