Greylist

Species regarded as toxic in the past and later removed from the reference list of toxic species because there is doubt whether they really produce toxins (no new evidence or confirmation for its toxicity) or because the species identity is not clear:

• Alexandrium balechii (Steidinger) Balech, 1995
• Anathece stratus (Komárek & Cronberg) Komárek, Kastovsky & Jezberová, 2011
• Aphanothece paralleliformis Cronberg, 2003
• Aureococcus anophagefferens Hargraves & Sieburth, 1988
• Aureoumbra lagunensis D.A.Stockwell, DeYoe, Hargraves & P.W.Johnson, 1997
• Cyanobacterium cedrorum (Sauvageau) Komárek, Kopecký & Cepák, 1999
• Halamphora coffeaeformis (C.Agardh) Levkov, 2009
• Microcystis panniformis Komárek, Komárková-Legnerová, Sant'Anna, Azevedo & Senna, 2002
• Microcystis pseudofilamentosa W.B. Crow, 1923
• Microcystis ramosa Bharadwaya, 1935
• Potamolinea aerugineo-caerulea (Gomont) M.D.Martins & L.H.Z.Branco, 2016
• Prorocentrum micans Ehrenberg, 1833