[2] P. parvum is responsible for red harmful algal blooms worldwide, causing massive fish killings.

Prymnesins also have unique features: The possession of only one methyl, but three chlorine atoms, four C-C triple bonds, sugars and an amino group.

In general primary and secondary metabolites such as fatty acids, polyketides and non-ribosomal peptides are synthesised by the acetate pathway.

[4] In 2024 the backbone of A-type prymnesins like prymnesin-2 was reported to be made by giant polyketide synthase enzymes dubbed the "PKZILLAs".

This is supported by the observation of competitive inhibition by the prymnesin-2 analogues, which assume the presence of a specific binding site on the blood cell surface.

The magnitude of P. parvum blooms are also increasing over the past decade compared to 30 years ago, with massive fish killings as result.