Commonly observed
Potentially Toxigenic (PTOX)
Cyanobacteria

To guide researchers and other labs, we have put together a list of cyanobacteria that have been shown to produce toxins and made it freely available to the public: PTOX Cyanobacteria list
At GreenWater Laboratories, we have been developing a list of the suspected and confirmed potentially toxigenic (PTOX) cyanobacteria in order to guide our analysts in toxin analysis recommendations.
Below are just a few examples of commonly observed freshwater cyanobacteria and their associated cyanotoxins.

Anabaena, Dolichospermum, Sphaerospermopsis

Benthic and planktonic nostocalean cyanobacteria (filamentous) that are commonly observed in bloom samples. Identification to species (and sometimes genus) level requires the presence of akinetes (resting cells) and heterocytes (nitrogen fixation cells). Therefore, these genera are grouped in order to provide conservative recommendations.
This group has illustrated the potential to produce the following toxins:

  • Microcystins
  • Saxitoxins (Paralytic Shellfish Toxins)
  • Anatoxin-a
  • Anatoxin-a(s)
  • Cylindrospermopsin / Epi-cylindrospermopsin

Aphanizomenon, Chrysosporum, Cuspidothrix

Similar to the Dolichospermum / Anabaena / Sphaerospermopsis group, these filamentous planktonic cyanobacteria are also commonly observed in bloom samples. Additionally, identification to species (and sometimes genus) level requires the presence of akinetes (resting cells) and heterocytes (nitrogen fixation cells). Therefore, these genera are grouped in order to provide conservative recommendations.
This group has illustrated the potential to produce the following toxins:

  • Saxitoxins (Paralytic Shellfish Toxins)
  • Anatoxin-a
  • Cylindrospermopsin

Gloeotrichia

This planktonic colonial cyanobacterium is comprised of radiating heteropolar filaments that have been illustrated to produce the following toxin:

  • Microcystins

Microseira wollei (Lyngbya wollei)

This sheathed filamentous cyanobacterium that can form floating or benthic mats and is considered a nuisance cyanobacteria in many ecosystems.
Microseira wollei has been illustrated to produce the following toxins:

  • Saxitoxins (Paralytic Shellfish Toxins)
  • Cylindrospermopsin / Epi-cylindrospermopsin

Microcystis

A commonly observed planktonic colonial cyanobacteria that is known to grow in dense blooms and typically produces the following toxin:

  • Microcystins

Oscillatoria

Benthic/Epiphytic filamentous cyanobacteria (without sheaths) that has been illustrated to produce the following toxins:

  • Aplysiatoxins
  • Microcystins
  • Anatoxin-a / Homoanatoxin-a
  • Cylindrospermopsin / Epi-cylindrospermopsin

Phormidium, Microcoleus, Kamptonema

Benthic/Epiphytic filamentous cyanobacteria (with or without sheaths) that has been illustrated to produce the following toxins:

  • Aplysiatoxins
  • Microcystins
  • Anatoxin-a / Homoanatoxin-a
  • Saxitoxins (Paralytic Shellfish Toxins)

Planktothrix

A planktonic filamentous group of cyanobacteria that is commonly observed in bloom samples, differentiated from Oscillatoria by gas vacuole presence.
Planktothrix has been illustrated to produce the following toxins:

  • Microcystins
  • Anatoxin-a

Raphidiopsis

previously classified as Cylindrospermopsis
These planktonic cyanobacteria are commonly observed in water column and bloom samples. The presence (in Cylindrospermopsis) or absence (in Raphidiopsis) of heterocytes was the main characteristic used to distinguish these genera of cyanobacteria. A recent manuscript utilized molecular methods on both described genera and the authors were not able to rationalize their current classifications. Therefore, Cylindrospermopsis has been merged with Raphidiopsis due to the latter nomenclature taking precedence.
Raphidiopsis has been illustrated to produce the following toxins:

  • Saxitoxins (Paralytic Shellfish Toxins)
  • Anatoxin-a
  • Cylindrospermopsin

Woronichinia

A planktonic cyanobacterium that grows in the colonial form similar to Microcystis, but with elongated (potato shaped) cells. Woronichinia has been illustrated to produce the following toxin:

  • Microcystins