Uptake of fenvalerate by the ostracod Chrissia halyi (Ferguson)

The accumulation of fenvalerate, a synthetic pyrethroid pesticide, in the ostracod Chrissia halyi was studied. The LC50 was 0.4 ug per litre. C. halyi were exposed to 0.13 or 0.3 ug fenvalerate per litre for 3 d and then transferred to clean water for 4 d. Fenvalerate residues were detected by gas-liquid chromatography. Accumulation reached a maximum on day 3 of exposure. Only a few individuals showed recovery. At the 0.13 ug per litre concentration, only 40 per cent of the organisms survived and a decline in the residues was observed indicating that the toxicant might have degraded or been partially eliminated. Mass mortality was observed at the 0.3 ug per litre concentration.