Phycotoxins from blue-green algae
Unpredictable poisonings of livestock and wildlife by waterblooms or scums of freshwater cyanophytes (cyanobacteria) occur when toxic strains of the common spe.cies dominate composition sufficiently to provide above-threshold levels of phycótoxins by susceptible animals. Known phycotoxins from freshwater cyanophytes are alkaloids, polypeptides or pteridines. New toxins produced by new strains have been described recently. Freshwater cyanophyte waterblooms can cause allergic reactions and, in water supplies, are suspected of causing outbreaks of human gastroenteritis. The structures of dermatitis-producing and non-dermatitis-producing phycotoxins from species of marine cyanophytes have been reported recently.