Genotoxicity evaluation of the insecticide imidacloprid on circulating blood cells of Montevideo tree frog Hypsiboas pulchellus tadpoles (Anura, Hylidae) by comet and micronucleus bioassays

RUIZ ARCAUTE C.; PEREZ IGLESIAS J.M.; NIKOLOFF, N.; NATALE, G.S.; SOLONESKI S.; LARRAMENDY M.L.

ECOLOGICAL INDICATORS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 45 p. 632 - 639

1470-160X

tAcute toxicity and genotoxicity of imidacloprid (IMI) was evaluated on Hypsiboas pulchellus (Anura: Hyli-dae) tadpoles exposed under laboratory conditions. A lethal effect was used as the end point for lethality,whereas the frequency of micronuclei (MNs) and DNA single-strand breaks evaluated by the single cellgel electrophoresis assay were employed as end points for genotoxicity. Experiments were performed ontadpoles at stage 36 (range, 35?37) according to the classification proposed by Gosner. Mortality studiesrevealed an LC50(96 h) value of 84.91 mg/L IMI (95% confidence limits, 77.20?93.04). While increasedfrequency of MNs was observed when 15 and 30 mg/L were assayed for 48 h, only 15 mg/L increased thefrequency of MNs in tadpoles exposed for 96 h. Furthermore, other nuclear abnormalities, i.e., binucle-ated cells and blebbed and notched nuclei, were induced in tadpoles exposed for both 48 h when treatedwith 15 mg/L and 96 h when treated with 15 and 30 mg/L. An increase in the genetic damage index wasobserved in tadpoles treated with 30 mg/L for 48 and 96 h. This study represents the first evidence ofacute lethal and sublethal effects exerted by IMI on tadpoles of an amphibian species native to Argentina.Finally, our findings highlight the hazardous properties of this insecticide for nontarget living speciesexposed to this agrochemical.