Romeo, once known as the world's loneliest frog, had until recently spent 10 years living in isolation at an aquarium.

He was thought to be the last of the Sehuencas water frogs, until scientists found him a Juliet on an expedition to a remote Bolivian cloud forest.

Once both creatures were cleared of a deadly infectious disease called chytridiomycosis, the pair were introduced.

Since their first date in January, there have been a few brief sexual encounters.

Researchers in Bolivia are hoping for a happier ending than for the original Romeo and Juliet.