A minimally invasive procedure for blood extraction from Xenopus laevis allows follow up studies without euthanasia.

Blood extraction is extremely important for the development of scientific research; however, the existing methods for amphibian´s blood sampling are invasive, mainly leading to the euthanasia of the animal. Therefore, less intrusive methods that allow the obtention of multiple samples from the same individual, are needed as an alternative to the common methods available. Hence, the aim of this study was to propose a minimally invasive method for obtaining blood from the hind leg of Xenopus laevis, that allows continuous sampling without compromising the wellbeing of the organisms. With this method, it was possible to extract blood and plasma from adults and juveniles, and the amount of sample was enough to perform biochemical and molecular assays to assess the viability of the blood. The results also revealed that this method is a convenient alternative to obtain blood without affecting the welfare of the experimental organisms, avoiding the cull of the animals, and the samples are viable for their use in follow up studies.

Prosopis laevigata a potential chromium (VI) and cadmium (II) hyperaccumulator desert plant.

The bioaccumulation of Cr(VI) and Cd(II) in Prosopis laevigata and the effect of these heavy metals on plant growth were assessed. P. laevigata seeds were cultured during 50 days on modified Murashige-Skoog medium supplemented with four different concentrations of Cr(VI) (0-3.4mM) and Cd(II) (0-2.2mM), respectively. Heavy metals did not stop germination, but smaller plants with fewer leaves and secondary roots were produced. Seedlings showed an accumulation of 8176 and 21,437 mg Cd kg(-1) and of 5461 and 8090 mg Cr kg(-1) dry weight, in shoot and root, when cultured with 0.65 mM Cd(II) and 3.4mM Cr(VI), respectively. These results indicated that significant translocation from the roots unto aerial parts took place. A bioaccumulation factor greater than 100 for Cd and 24 for Cr was exhibited by the seedlings. P. laevigata can be considered as a potential hyperaccumulator of Cd(II) and Cr(VI) species and considered as a promising candidate for phytoremediation purposes.