FIGURE 3. A–D. TEM micrographs of Spelaeonaias floccida showing cell division and mode of branching. A. Filament with short barrel cells showing a general view of dividing cells for branch formation; the oblique division of an initial cell at arrow. B. Oblique section at a particular part of a filament showing one heterocyte (h) with a polar plug of cyanophycin (cy) connected to the adjacent cell by a neck; note the extra wall layer (wl) surrounding the heterocyte. C. Cell division at a certain region of the filament and formation of a new septum (s); D–E. After the first division of the initial cell (ic) the resulting cell (arrow) changes polarity and is further dividing for the formation of a secondary branch. Scale bars = 2 μm (B) and 5 μm (A–D).

Published as part of Lamprinou, Vasiliki, Christodoulou, Maria, Hernandez-Marine, Mariona, Parmakelis, Aristeidis & Economou-Amilli, Athena, 2016, Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece), pp. 171-185 in Phytotaxa 282 (3) on page 178, DOI: 10.11646/phytotaxa.282.3.1, http://zenodo.org/record/13645684