[2] A tremendous body of work on Planktothrix ecology and physiology has been done by Anthony E. Walsby, and the 55.6 kb microcystin synthetase gene which gives these organisms the ability to synthesize toxins has been sequenced.

[6] P. agardhii is commonly found at most latitudes in shallow and turbid lakes where it can tolerate continuous mixing of the water column.

[9] Under the action of wind-induced internal waves, P. rubescens can be moved vertically by several meters following the movements of the metalimnion, which in turn modifies rapidly (within a day) the light conditions experienced by the filaments.

Planktothrix grows by cell division in a single plane to form unbranched structures of average length around 4 μm, but unlike other Oscillatoriales, these trichomes are phototactic.

Typically, Planktothrix filaments do not have specialized cells such as akinetes or heterocysts, and do not produce mucilaginous envelopes, except for some rare species but only under stress conditions.

[16] Harmful algal blooms caused by not only Planktothrix but also other forms of cyanobacteria including Dolichospermum (Anabaena) or Microcystis have correlation to toxic effects for humans leading to devastating impacts to agriculture.