Meeting Abstract
Xenopus laevis is generally considered as one of the worst invasive amphibians world-wide having colonized many countries on at least four continents and with new invasions being reported on a regular basis. Despite the negative impact this species has on native amphibians and freshwater invertebrates, the invasive populations provide an excellent model system to explore whether and how these animals have adapted to novel ecological conditions. Here we compare external morphology, organ size and limb muscle mass for two invasive populations characterized by different habitats. Whereas in France this species has invaded ponds and stagnant water bodies, in Portugal the species is present in fast flowing streams. Our results show significant differences with animals in France relatively wider heads relative to their size while Portugese individuals which have relatively longer heads. Moreover, Portugese frogs had a longer tibia and longer and wider ilia, larger lungs and a heavier intestinal tract. French frogs had longer femora, longer fingers and toes and males specifically had larger kidneys. In terms of muscles only the pectineus was better developed in the Portugese frogs whereas the adductor longus, the quadratus femoris, the semimembranosus, the semitendinosus and the tibialis anticus are better developed in frogs from the French population. These results show that frogs have adapted to the specific constraints of the different habitats.
