Nostocales

The Nostocales are an order of cyanobacteria containing most of its species. It includes filamentous forms, both simple or branched, and both those occurring as single strands or multiple strands within a sheath. Some members show a decrease in width from the base, and some have heterocysts.

Nostocales
Anabaena flos-aquae
Scientific classification
Domain:	Bacteria
Phylum:	Cyanobacteria
Class:	Cyanophyceae
Order:	Nostocales T.Cavalier-Smith
Families[1][2]
Aphanizomenonaceae Elenkin Capsosiraceae (Geitler) Elenkin Chlorogloeopsidaceae (Mitra) Mitra & Pandey Fortieaceae Gloeotrichiaceae Komárek et al. 2014 Godleyaceae Hauer, Mareš, Bohunická, Johansen, & Berrendero-Gomez Hapalosiphonaceae Elenkin Nostocaceae C. A. Agardh ex Kirchner Rivulariaceae Kützing ex Bornet & Flahault Scytonemataceae Rabenhorst ex Bornet & Flahault Stigonemataceae Borzì Symphyonemataceae Hoffmann, Komárek, & Kaštovský Tolypothrichaceae Hauer, Mareš, Bohunická, Johansen, & Berrendero-Gomez
Synonyms
Hormogonales

Environmentally, Nostocales (Sphaerospermopsis aphanizomenoides) is largely disregarded and not widely studied. However, a recent study suggests that the invasive cyanobacterium is occupying temperate lakes and thriving in them. Using principal component analysis (PCA) and the Mann-Whitney U test, results showed that total phosphorus concentration was the primary causation for the increasing abundance of S.aphanizomenoides. Nostocales is known to grow in temperate environments consisting of poor light conditions and high phytoplankton biomass, commonly found in shallow lakes. [3]