Nutria (Spanish name in Costa Rica))

I agree, most definitely an otter.

Ah, el problema con los nombres comunes. Perdona mi implicación que no son correctos. Traducción puede ser incorrecta, ya que estoy usando Google Translate para traducir del Inglés al Español. Ah, the problem with common names. Forgive my implication that you were incorrect. Translation may be incorrect as I'm using Google Translate to translate from English to Spanish.

That's definitely an otter, a nutria is what you folks sometimes call a Coypu

I think you may have the scientific name correct, but the common name is "Neotropical River Otter" not nutria, which is a different animal. Great photos of a rare animal!