Effects of the cyanobacterial neurotoxin B-N-methylamino-L-alamine (BMAA) on the survival, mobility and reproduction of Daphnia magna

In short-term tests and chronic life table assays, Daphnia magna was exposed to the cyanobacterial neurotoxic non-protein amino acid ß-N-methylamino-l-alanine (BMAA). BMAA was not acutely lethal to Daphnia (LC50–48h > 10 000 µg L-1), but reduced mobility (IC50–48h 40 µg L-1) and affected life history characteristics. Animals showed a tendency to later age at first reproduction, larger size at first reproduction, smaller clutch size and lower population growth rates with higher concentrations of BMAA. Animals that had been kept in either food-free medium or were fed the green alga Scenedemus obliquus with BMAA accumulated BMAA in their tissue. The highest measured bioconcentration factors were 275 in adult D. magna and 3821 in their neonates. This bioconcentration of the neurotoxic BMAA in D. magna suggests that these animals may be an important vector of BMAA in the pelagic food web