Biological endpoints, enzyme activities, and blood cell parameters in two anuran tadpole species in rice agroecosystems of mid-eastern Argentina

ATTADEMO A.M.; PELTZER P.M; LAJMANOVICH R.C; CABAGNA ZENKLUSEN M; JUNGES C.M; BASSÓ A

ENVIRONMENTAL MONITORING AND ASSESSMENT

SPRINGER

Lugar: Berlin; Año: 2014 p. 635 - 649

0167-6369

Different biological variables of tadpoles, includingsurvival, development and growth rates, andbiomarkers [cholinesterases, glutathione-S-transferases(GST), and blood cell morphology] were evaluated intwo anuran species, Scinax squalirostris (Hylidae) andLeptodactylus mystacinus (Leptodactylidae), using in situexperimental chambers in a rice field (RF) sprayed withinsecticide Lambda-cyhalothrin (LTC) by aircraft inSanta Fe Province, Argentina. We found a significantdecrease in body weight (0.62±0.04 g) of L. mystacinusand an increased development rate of S. squalirostris inindividuals from RF (41±1; Gosner) with respect toindividuals from the reference site (RS: 0.93±0.04 gand 37±0; respectively). In S. squalirostris, individualsfrom RF mean values of butyrylcholinesterase activitiesdecreased at 48 (4.09±0.32 nmol min-1 mg-1 of TP) and96 h (3.74±0.20 nmol min-1 mg-1 of TP), whereas inhibitionof acetylcholinesterase was observed at 96 h (47.44±2.78 nmol min-1 mg-1 of TP). In L. mystacinus from RF,an induction of acetylcholinesterase activity was observedat 96 h (36.01±1.09 nmol min-1 mg-1 of TP).Glutathione-S-transferase levels varied between species,being higher in L. mystacinus individuals but lower in S.squalirostris from RF at 48 (272.29 ±11.78 and 71.87±1.70 nmol min-1 mg-1 of TP; respectively) and 96 h(279.25±13.06 and 57.62±4.58 nmol min-1 mg-1 of TP,respectively). Blood cell parameters revealed a lowernumber of mitotic cells (MC: 0.36±0.31%o for S.squalirostris and 0.08±0.05 %o for L. mystacinus)and higher number of eosinophils (E: 3.45±1.75%o for S. squalirostris and 7.64±0.98 %o for L.mystacinus) in individuals from the RF than inindividuals from the RS (MC: 2.55±0.74 %o for S.squalirostris and 1.87±0.72%o for L. mystacinus; andE: 0.13±0.09 for S. squalirostris and 3.20±0.80 for L.mystacinus). Overall, our results demonstrate the existenceof apparent differences in sensitivity betweenspecies in a series of sublethal responses to shorttermexposure in RF after the application of Lambdacyhalothrin.We suggest that the integral use ofbiological endpoints (development and growth) togetherwith biomarkers (cholinesterase, GST, andblood cell parameters) may be a promising integralprocedure for investigating pesticide exposure in wildfrog populations.