title: The toxicities of a polyunsaturated fatty acid and a microcystin to Daphnia magna.
abstract: Polyunsaturated fatty acids (PUFAs) are essential components of zooplankton diets. However, studies with PUFAs from cyanobacteria indicate toxic properties. We investigated the toxicity of the PUFA gamma-linolenic acid and the cyanobacterial peptide toxin microcystin-LR to Daphnia. The PUFA was acutely toxic at a concentration of 9 micrograms ml-1. The effect of microcystin-LR was not statistically significant at the concentration used (3 micrograms ml-1), but an additive effect with the PUFA was observed. Relative to LC50-values of well-known pollutants, the PUFA was intermediately toxic. The activity equaled that of microcystin-LR, which is commonly treated as one of the most potent cyanobacterial toxins. Our results suggest that the toxic properties of PUFAs deserve more attention.
authors.affiliation: Umeå Marine Sciences Centre/Marine Ecology, Umeå University, Norrbyn, SE-910 20 Hörnefors, Sweden. marko.reinikainen@eg.umu.se
authors.forename: M
authors.initials: M
authors.lastname: Reinikainen
authors.forename: J A
authors.initials: JA
authors.lastname: Meriluoto
authors.forename: L
authors.initials: L
authors.lastname: Spoof
authors.forename: K
authors.initials: K
authors.lastname: Harada
mesh_terms: D000818:Animals; D003621:Daphnia; D020387:Food Chain; D007928:Lethal Dose 50; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic / Q000009:adverse effects*; D010839:Phytoplankton; D017965:gamma-Linolenic Acid / Q000009:adverse effects*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; D017965:gamma-Linolenic Acid; C057862:cyanoginosin LR