FIGURE 4. A–C in Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)

FIGURE 4. A–C. Confocal (CLSM) photomicrographs showing filaments of Spelaeonaias floccida covered by sheaths. A. 41 x-y optical sections (z step= 0.13 μm) showing the Y-type of true branching; note the central spaces devoid of fluorescence in the filaments, corresponding to the area of nucleoids. B. 30 x-y optical sections (z step= 0.13 μm) showing a degraded basal cell (dc) promoting a false branching. C. Main filament with secondary branches; division of initial cells (at arrows) implying further formation of secondary branches. Color allocation: DNA nucleic acids labelled with Hoechst 33258, cyan; reflection from minerals, white; autofluorescence of extracellular polymeric substances, green; colocalized autofluorescence of cyanobacteria in the red (phycobilins) and blue channels (chlorophylls), magenta. Scale bars = 10 μm.