The teratogenicity of the pesticide nereistoxin (NTX) and its derivative thiocyclam (THI) towards aquatic life was dramatically constrained by a synthetic nanoreceptor, cucurbit[7]uril, through selective encapsulation of the pesticides (KCB[7]-NTX of 3.24(+/- 0.31)x10(6) M-1 and KCB[7]-THI of 7.46(+/- 0.10)x10(5) M-1), as evidenced by the rate of hatchability, morphology development, and tyrosinase activity of zebrafish larvae incubated with the pesticides (3-300 mu m) in the absence and in the presence of 300 mu m cucurbit[7]uril, demonstrating the significant potential of the nanoreceptor in managing ecological pollution of these pesticides.