Studies on the species Aphanizomenon flos-aquae have shown that it can regulate buoyancy through light-induced changes in turgor pressure.

Aphanizomenon may become dominant in a water body partially due to their ability to induce phosphate-limitation in other phytoplankton while also increasing phosphate availability to itself through release of cylindrospermopsin.

Algal Blooms formed from Aphanizomenon species tend to be very toxic and create a variety of toxins.

[9] Aphanizomenon species may produce cyanotoxins including cylindrospermospin (CYN), lipopolysaccharides (LPS), anatoxin-a, saxitoxin and BMAA.

CYNs are a toxin that is especially toxic for the liver and kidney, thought to inhibit protein synthesis.

Anatoxin-a is a type of anatoxin, it is normally released during algal blooms in lakes, causing exposure to animals around it.

[13] Aphanizomenon may form large colonies as a defense against herbivore grazing, especially Daphnia in freshwater.