The frog's blue-green colored bones are also visible, throughout the arms, legs, jaw and knee of the individual pictured above. Adults generally measure between 21 and 32 millimeters.

They are called Cascade Glass Frogs because adults tend to frequent waterfalls. In the dry season males have even been observed calling from spray zones.

If a calling male attracts a female the two will mate and will usually lay their egg clutch on the upper surfaces of leaves overhanging the stream. Cascade Glass Frogs differ from other glass frogs in Drake Bay because they will also place their egg clutches on rocks along streams or in the spray zone of a waterfall.

Egg clutches have a dark coloration and lack the thick jelly mass that surrounds the eggs of many of it's close relatives. Very little is know about the behavior of juvenile glass frogs in the wild.

References:

Kubicki, B.  2007  Costa Rica Glass Frogs  Editorial INBio

Leenders, T.  2001  A Guide to Amphibians and Reptiles of Costa Rica  Zona Tropical

Savage, J.  2002  The Amphibians and Reptiles of Costa Rica   University of Chicago Press