Mai T., Johansen J.R., Pietrasiak N., Bohunická M., Martin M.P. Revision of the Synechococcales (Cyanobacteria) through recognition of four families including Oculatellaceae fam. nov. and Trichocoleaceae fam. nov. and six new genera containing 14 species // Phytotaxa, 2018. Vol. 365 (1): 001-059.
Differing from other species in the genus based on the frequent formation of spirals; the internal loop near the base of the Box B helix of the ITS region at position 5–6/31–32 (Fig. 7a) and unique V2 and V3 helices of the ITS region.
Colony bright blue green, with radial fasciculation, penetrating the agar. Filaments long or short, sometimes forming nodules (Fig. 10a), or loosely to tightly spirally coiled (Figs. 10b–g), rarely singly (Fig. 10i) or doubly false branched (Fig. 10h), 2.0–6.0 μm wide (to 14 μm wide at nodules). Sheath firm, colorless, usually attached to trichome, occasionally softer, widened (Figs. 10b, i–k), sometimes irregular and stratified (Fig. 10k). Trichomes untapered, more or less constricted at the distinctly visible cross-walls, occasionally with tight, regular, screw-like coils (Fig. 10l), necridia not observed, 1.5–2.5–(3.0) μm wide. Cells slightly shorter than wide to longer than wide, rarely with a single central granule, with parietal thylakoids, 1.0–3.0 μm long. End cells rounded.
D1-D1’ helix 85 nucleotides long, with basal 3’ side loop of 8 unpaired nucleotides (5’-UCAUCCCA-3’), mid-helix region with two unpaired adenine residues at position 14–15, internal loops at position 22–25/56–60 and at 32–33/48–49. Terminal loop 5’-GAAA-3’ (Fig. 6a). Box B helix 36 nucleotides long, bearing 4 nucleotides at terminal loop, and one small internal loop at position 5–6/31–32 (Fig. 7a). V2 helix 24 nucleotides long, with terminal loop of 6 nucleotides (Fig. 8a). V3 helix 96 nucleotides long, with several internal loops at position 5–6/92, 10–14/86–88, 18/81–82, 36–37/62–63, with two mismatches of 5’-A/G-3’ and 5’-G/G-3’ at 29/70 and 44/55. Terminal loop sequence 5’-GAGA-3’
