Pseudanabaena

Taxonomy

Order Pseudanabaenales
Family Pseudanabaenaceae
Genus Pseudanabaena

Morphology

Trichomes solitary or forming fine mats. Trichomes typically straight or curved, less commonly wavy; usually fairly short, consisting of a small number of cells, or (uncommonly) long, with many cells; usually conspicuously constricted at crosswalls; without firm sheaths, but may have wide, diffluent mucilaginous envelopes. Immotile or facultatively with slow gliding movement. Cells mostly cylindrical with rounded ends, or sometimes nearly barrel-shaped; almost always longer than wide, rarely almost isodiametric; apical cells cylindrical with rounded ends in typical Pseudanabaena, or pointed in subgenera Ilyonema and Skujanema. One or two polar (near crosswalls) aerotopes may be present, though such species may eventually be classified into a separate genus.

Ecology

Recorded from a variety of habitat types: planktic, metaphytic, periphytic, and benthic in various waters; on soils; endogloeic, in the mucilage of algal colonies; and in thermal and mineral springs.

References

Johansen, J. R., & Komárek, J. (2015). Filamentous Cyanobacteria. In J. D. Wehr, R. G. Sheath, & J. P. Kociolek (Eds.), Freshwater Algae of North America: Ecology and Classification (2nd ed., pp. 146-150). Waltham, MA: Elsevier.

Komárek, J. & Anagnostidis, K. (2008). Cyanoprokaryota-2. Teil/Part 2: Oscillatoriales. In B. Büdel, G. Gärtner, L. Krienitz, & M. Schagerl (Eds.), Süßwasserflora von Mitteleuropa (Vol. 19/2, pp. 70-72). Heidelberg, Germany: Spektrum.

Strunecký, O., Ivanova, A.P., & Mareš, J. (2023). An updated classification of cyanobacterial orders and families based on phylogenomic and polyphasic analysis. Journal of Phycology, 59: 12-51. https://doi.org/10.1111/jpy.13304