Têtard de Xénope lisse âgé de 6 jours observé à la loupe binoculaire

Six-day old tadpole of the African clawed frog, Xenopus laevis, exposed to pollutants, observed using a binocular magnifying glass. Here, alcian blue staining has been used to highlight its cartilaginous structures. This labelling, together with an automatic biometric measurement protocol developed specially for this model, makes it possible to evaluate precisely the morphological impact of exposure to environmental contaminants. The tadpoles are exposed to contaminants such as cadmium, lead or copper (metals), or glyphosate or deltamethrin (pesticides), for example. After image acquisition, processing, segmentation and morphological analysis are performed using an ImageJ plug-in developed specially for this model. In addition to a qualitative description of any malformation, this automatically provides a large amount of quantitative information (length, perimeter, distance between the eyes, etc.). Recent studies have shown that 41% of amphibian species are under threat. Their skin is highly permeable and their contact with the water means they experience particularly high exposure to pollutants.