Spirotaenia filiformis G.J.P.Ramos, C.E.M.Bicudo & C.W.N.Moura (2017: 268) (Fig. 18)

Cells 17–31 times longer than broad, long-cylindrical, narrowed toward the poles, poles rounded. Cells straight or slightly curved. Chloroplast a parietal ribbon making 3.5–8.5 turns, pyrenoids in series, one per turn. Cell dimensions: length 26–94 μm, breadth 1.5–3 μm.

Geographic distribution: South America: Brazil (Ramos et al. 2017).

Ecology: plankton; bromeliad phytotelmata

Note: This species was described a few years ago based on material collected in bromeliad tanks (phytotelm) in Bahia State, northeastern Brazil. To date, this remains the only known record, suggesting a possible endemic status within Brazil. Its thinnest and elongated cylindrical cells are remarkable, making this species easily to be identified within the genus.