The accumulation of cylindrospermopsin from the cyanobacterium Cylindrospermopsis raciborskii in tissues of the Redclaw crayfish Cherax quadricarinatus.

Redclaw crayfish, Cherax quadricarinatus harvested from an aquaculture pond infested by a bloom of the cyanobacterium Cylindrospermopsis raciborskii (order: Nostocales), were shown to accumulate the toxic alkaloid cylindrospermopsin. Pond water samples collected during the bloom contained 589 microg l(-1) of the toxin (93% in the cyanobacterial cells, 7% in the water). Crayfish from the pond contained cylindrospermopsin at concentrations of 4.3 microg g freeze dried hepatopancreas tissue and 0.9 microg g freeze dried muscle tissue. Trichomes of C. raciborskii were observed in gut contents of crayfish harvested during the cyanobacterial bloom, indicating that the most likely mechanism for accumulation of the toxin was by ingestion of cyanobacterial cells. Crayfish subjected to an extract of harvested bloom material under laboratory conditions for a period of 14 days were also found to accumulate cylindrospermopsin, indicating that this toxin is also absorbed into the tissues by direct uptake of the toxin in solution.