M. foliacea var. quadrinflata Scott & Prescott, 1961

Levanets, Anatoliy & Janse van Vuuren, Sanet, 2023, Morphology, taxonomy, biogeography and ecology of Micrasterias foliacea Bailey ex Ralfs (Desmidiales, Zygnematophyceae), PhytoKeys 226, pp. 33-51 : 33

7. M. foliacea var. quadrinflata Scott & Prescott, 1961

M. foliacea var. Micrasterias foliacea quadrinflata Scott & Prescott, 1961. “Hydrobiologia” 17(1-2): 48, Pl. 15, figs 5-8.

Morphology.

M. foliacea var. quadrinflata differs from the type in having two large, prominent semi-ellipsoidal hollow swellings at the base of the lateral lobes, each bearing a long spine at the narrow ends. In addition, there may or may not be, four other long spines on each semicell, two adjacent to each of the swellings. Cells are 69-72 μm long and 63-72 μm wide. The isthmus is 12 μm wide and the teeth are 15-18 μm long ( Scott and Prescott 1961).

Distribution.

The distribution of this variety is plotted in Fig. 2 (with more detailed information in Suppl. material 2). It is limited to the Hindustan and Indochina peninsulas and Indonesian archipelago and was recorded from India, Indonesia, Malaysia and Thailand.

Habitats and ecology.

Variety Micrasterias quadrinflata was found in freshwater lakes, rivers, reservoirs, swamps and wetlands (India, Indonesia and Malaysia), as well as in a rice paddy field in Thailand.

In Malaysia, the shallow parts and edges of the Tasek Bera swamp lake were covered with Lepironia articulata associations. Aquatic plants such as Utricularia spp., Hydrilla sp., Nymphoides indica and Pandanus helicopus were present in still water areas, while Utricularia sp., Cryptocoryne griffithii , Scirpus confervoides and Pandanus helicopus were present in running water ( Ratnasabapathy and Kumano 1974). At the time of sampling the temperatures ranged between 23.4 and 33.4 °C (in still water) and between 23.8 and 26.9 °C (in running water) and the pH ranged between 4.7 and 5.3 Ratnasabapathy and Kumano 1974). In South Sumatra it was also found in acidic waters in Lebak Danau (pH between 5.0 and 5.5; Scott and Prescott 1961).

Figures

Figure 2. Worldwide distribution of different varieties of Micrasterias foliacea.