International audienceBecause ecosystems on our planet are now polluted by mutagenic substances to a greater extent than ever before, it is increasingly suggested that human activities are oncogenic for wildlife species. To improve our knowledge on these timely issues, experimental evidence should however complete correlative field studies. Hydras and Planarians are freshwater invertebrates which sometimes develop tumors. Hydras tumors are able to be vertically transmitted during asexual reproduction. Because the etiology of these atypical tumors is unknown, our objective is to explore the extent to which they could be, at least partially, linked to human activities. Specifically, this project aims at testing if UV radiation (both UV-A and UV-B) and/or cadmium exposure can promote tumorigenesis, and to evaluate how transmissible these inducible tumors are. A second objective is to explore the extent to which UV & cadmium exposures induce tumors in planarians. This project not only represents an original contribution to the field of ecology in human-altered habitats, but also improves our knowledge on the evolutionary ecology of transmissible malignant cell lines, and host-tumor interactions