The woman claims that it was not the first time she has seen something resembling an eel, but with "wrinkled skin and human teeth", according to reports.
"This 'handsome one' swam down the river to go in a rice field. We do not know what it is, but we have found another one… Be careful"! Maria Julia Candotti wrote on her Facebook page.
Commentators have called the fish "disgusting and frightening".
Pablo Scarabotti, a scientist from the National Institute of Lumnology of Conicet, has identified the creature as a South American lungfish (epidosiren paradoxa) which can breathe air but is usually found in swamps and slow-moving waters. He also said that the fish was unique to South America.