Episode 78 – Reticulated Glass Frog: Clear Frogs Full Hearts

“And today we’re talking about a creature with a clear eyes and a full heart. But more on that later.”

When it comes to relationships, one of the best qualities is transparency. When you find that special someone, you can really open up and let that special someone see your heart—as well as your liver and small intestine. The reticulated glass frog has nothing to hide, but it does possess secret kung-fu powers that only humans and a select few unfortunate wasps have come to learn about. But if you’re going to be a frog dad, it pays to be a ninja frog dad here in Life Death and Taxonomy.


  • Glass frogs are small, bright green frogs.
  • Reticulated glass frogs are unique because of their yellow spots and tiny black dots along their backs.
  • Glass frogs get their name from the fact that they are transparent, especially on their underbellies. 
  • You can see veins, organs, and bones through their thin, shiny skin.
  • The heart is visible but other organs like the intestines and liver are wrapped in an opaque coat of white guanine.
  • We aren’t totally sure why they are transparent, but some believe that it serves a purpose in camouflage.

Location and Range

  • Glass frogs are common in the Central and South American rainforests and are most densely populated in Costa Rica.
  • They prefer moist environments, especially by forest streams and swampy lowlands.
  • They live among green foliage where they can hide and camouflage.
  • If you’re trying to hide from predators of brown dirt or grey rocks, it’s not easy being green.

Measure Up

Males – 19.5 to 24.0 mm – 22 mm – How many glass frogs go into the height of Costa Rica’s Turrialba Volcano (10,958 ft)? Hint: The Turrialba Volcano is an active volcano with eruptions as recently as 2017. The park area surrounding the volcano has been closed because of frequent volcanic activity sending huge clouds of ash into the air. Answer: 151,818 male glass frogs.

Hatchling tadpoles – 12 mm – How many tadpoles go into the length of the largest piece of curved glass in the world? (47 feet) Hint: The glass is part of Apple’s headquarters and 3,000 sheets wrap around the entire building. Answer: 1,193.8 glass frogs

Fast facts

  • Glass frogs are nocturnal predators that spend the night hunting for small insects.
  • Male glass frogs are territorial and maintain their areas by constantly calling out to other males.
  • If a male enters another frog’s territory, their call will change to a warning squeak.
  • If the intruder doesn’t leave, the defending male will wrestle him and try to pin him down.
  • Reticulated glass frogs are rarely seen but they aren’t threatened.
  • They are tiny and elusive, only coming out at night, deep in the rainforest.
  • Kermit the Frog’s design came from glass frogs. Kermit’s distinctive pupil shapes are inspired by the unique eyeballs of the glass frog.