Muskrat or Nutria?

I made a few fast shots at Vltava river in Prague without having time to look by binoculars and I was convicted that it was  Muskrat (Ondatra zibethicus) I saw. Now looking at the photo I thing is is more probably young Nutria (Coypu)  (Myocastor coypus).  Both are invasive species, but Muskrat is living in the Czech republic for ca. one hundred years and Nutria is the matter of last 10-15 years and is spreading explosively. 

 Pentax K50 f 7,1; 1/800 sec.; ISO 800;  lens zoom 4,5-6,3/55-300 mm