Efectos letales y subletales del glifosato (roundup®) sobre larvas de dendropsophus colombianus (anura: hylidae)

Abstract

spa:El uso de los herbicidas como el glifosato en cualquiera de sus marcas comerciales ha sido un tema de controversia en las últimas décadas. Ha sido usado ampliamente en la agricultura para la erradicación de malezas y en el programa de aspersión aérea para erradicación de cultivos ilícitos hasta el año 2015. Diversos estudios han revelado efectos letales y subletales en anfibios, en su mayoría en renacuajos. Se evaluó la toxicidad aguda y crónica del glifosato en larvas de Dendropsophus columbianus, donde se encontró un efecto en la medidas morfométricas de la cabeza y en el desempeño locomotor. Se considera que el efecto del glifosato en D. columbianus es moderadamente tóxico.

eng:The use of herbicides such as glyphosate in any of its commercial brands has been a subject of controversy in recent decades. This herbicide has been widely used by farmers for weed eradication and from 2000 to 2015 in the aerial spraying program for the eradication of illicit crops. Although their half-life in water is shorter than that in soil, amphibians are susceptible to this type of contaminant due to their dual life cycle. There have been a number of studies on the lethal and sublethal effects of glyphosate on various species around the world, with acute and chronic toxicity tests revealing a wide variety of results as measured by the median lethal dose and some body measurements. Evaluating these lethal effects with the median lethal dose (LC50) and sublethal effects on mormometric measurements and locomotor performance of glyphosate in its Roundup® commercial presentation on Dendropsophus colombianus larvae was the objective of this study. Adults of D. columbianus were collected and placed in fish tanks to induce an amplexus and subsequent fertilization of the clutch, waiting until the 25th larval stage to start the experiments. The LC50 was found to be 4mg/L over a 96h exposure period. The chronic tests revealed there was an effect of the sublethal doses LC01 and LC10 on the measures of head width and weight of the tadpoles, also with geometric morphometry variations in the shape and size of the head were revealed. Finally, the herbicide had an effect on locomotor performance where it directly affected exploration rate and average freezing time. Thanks to these findings, he considers that glyphosate is moderately toxic in this type of organisms.