Planktic morphospecies of the cyanobacterial genus Anabaena = subg. Dolichospermum - 1. part: coiled types.

This small tropical cyanobacterial group, containing null volzii Lemmermann and a few related species (A. fuellebornii SCHMIDLE, A. unispora GARDNER, A. mysorensis GONZALVES & KAMAT), differs substantially phenotypically from all other planktic or benthic null types, mainly by the subsymmetric structure of the trichomes, type of akinete formation and restricted ecology. The taxonomic uniformity of all other Anabaenalike clusters (typical benthic...