Lethal and sublethal effects of the pirimicarb-based formulation Aficida® on Boana pulchella (Dumeril and Bibron, 1841) tadpoles (Anura, Hylidae)

Acute lethal and sublethal toxicity of the pirimicarb-based commercial formulation Aficida (R) were evaluated on Boana pulchella tadpoles. Whereas mortality was used as end point for lethality, frequency of micronuclei and other nuclear abnormalities as well as alterations in the frequency of erythroblasts in circulating blood as biomarkers for genotoxicity and cytotoxicity, respectively. Swimming, growth, developmental and morphological abnormalities were also employed as sublethal end points. Results show that the species is within the 13th percentile of the distribution of acute sensitivity of species to pirimicarb for aquatic vertebrates. Results revealed values of 23.78 and 101.45 mg/L pirimicarb as LC50(96) h for GS25 and GS36 tadpoles, respectively. The most evident effects were related with the swimming activity with NOEC and LOEC values within the 0.005-0.39 mg/L pirimicarb concentration range. Aficida (R) induced DNA damage at the chromosomal level by increasing micronuclei frequency and other nuclear abnormalities, ie., lobbed and notched nuclei and binucleated cells. Cellular cytotoxicity was found after Aficida (R) treatment. The presence of abdominal oedemas in exposed organisms and thus flotation response of organisms could be proposed as a new sensitive exposure parameter. The multiple end point assessment approach used allowed a complete understanding the multi level of effects occurring by exposure to pirimicarb, at least in B. pulchella.