Fins are relevant non-lethal surrogates for muscle to measure stable isotopes in amphibiansNadège Bélouard, Eric J. Petit, Dominique Huteau, Adrien Oger and Jean-Marc PaillissonKnowl. Manag. Aquat. Ecosyst., 420 (2019) 2DOI: https://doi.org/10.1051/kmae/2018040