TOXIC EFFECTS OF AGROCHEMICAL HERBICIDES ON Pomacea canaliculata.

VEGA, IA; GARCÍA, B; ALBRECHT, E; GIRAUD BILLOUD, M.

Mendoza

Congreso; XXXVI Reunión científica anual de la Sociedad de Biología de Cuyo; 2018

Sociedad de Biología de Cuyo

Gastropods have been proposed as bioindicators of environmental pollution. In general, they are able to evidence some xenobiotics originated from agricultural practices and industrial emissions. Pomacea canaliculata (Caenogastropoda, Ampullariidae) has been proposed as indicator organism because of it widely distribution in aquatic ecosystems around the world and the demonstrated deleterious effect of some endocrine disruptors, like the organic compounds tributyltin (TBT) and triphenyltin (TPT), respectively used in paints and in agriculture, that induces masculinization in females. The aims of this study were: 1) to evaluate the nominal median lethal concentration (LC50) and nominal no-observed-effect on lethality concentration (NOECL) at 48h of paraquat and fluroxypyr agrochemicals in P. canaliculata, and 2) to determinate a possible masculinizing effect of both herbicides, after a chronic exposition, in females of this species. Adult (4 month old) animals from our cultured strain were used for the assays. In the first experiment, we observed that paraquat LC50 was 40 µg/g of drained mass (DM) and NOECL was 10 µg/g DM, while for fluroxypyr LC50 was 44 µg/g DM and NOECL was 15 µg/g DM. In the second experiment, females received seminally (about 4 weeks) tolerated intramuscular doses of both herbicides (paraquat 2 µg/g DM and fluroxypyr 10 µg/g DM). After the exposure period (28 days), snails were sacrificed and the female copulatory apparatus was observed under a stereoscopic microscope and the lengths of the penis and penial sheath were measured with a caliper (near to 0.5 mm). Also, developmental index (DI) of female masculinization was determined. Only fluroxypyr exposed females showed a significant increase of the penis length and the DI. The results indicate that young female development of the copulatory apparatus of P. canaliculata could be used as a bioindicator of fluroxypyr contamination. Further studies exploring other toxic effects of herbicides, like reproductive affectation or oxidative stress induction, could be useful tools for monitoring environmental contamination in agriculture practices.