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Emerald Glass Frog

Espadarana prosoblepon


adult males to 27mm, females to 32mm, adult males have prominent bluish rounded bone spur (humeral hook), clearly visible on his upper arm, a midge is feeding on him in the photos, bones dark green, males are territorial and can get into scuffles which can last 45 minutes with intruders


rainforest, riparian habitats with dense vegetation


One of 4 species of glass frog spotted in Yatama reserve. We spotted this species a couple of times. Since it was night, it was tough to get a habitat shot but this was on a rock beside a small stream.

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SukanyaDatta 7 months ago

Blue-green pigment in the bones of the garfish (Belone belone) and eelpout (Zoarces viviparus).

dandoucette 7 months ago

I know other glass frogs also have green bones but I wasn't aware of any other animals or amphibians.

SukanyaDatta 7 months ago

I am reading up more and more on green bones and the other species that have them. Fascinating.

dandoucette 7 months ago

I'm glad you researched it Sukanya because I had no idea! Thanks and thanks ornithoptera!

SukanyaDatta 7 months ago

It seems that the green bone colouration is caused by an accumulation of a metabolic byproduct called biliverdin, a green bile pigment. (But why bile pigment should land up in the bone still eludes me.) Anyway, learnt something FANTASTIC today. Thank you Natgeo, dandoucette and PN.

Ornithoptera80 7 months ago

Wow, great shot

SukanyaDatta 7 months ago

So cute! Green bones!!! How?? So interesting.

Spotted by

Heredia, Costa Rica

Spotted on Mar 5, 2020
Submitted on Mar 21, 2020

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