Lucas Bustamante / Two Limon glass frogs (Sachatamia ilex) sitting on plant, one above the other, Canande, Esmeraldas.

Alex Hyde / Yellow-flecked glassfrogs (Sachatamia albomaculata) mating pair, Osa Peninsula, Costa Rica

Niall Benvie,Niall Benvie / Common Frog (Rana temporaria) at surface, against white background. Scotland, UK, July.

Pete Oxford / Glass Frog (Espadarana callistomma / centrolenidae). Captive. Choc Region of northwest Ecuador.

Pete Oxford / Portrait of an Emerald Glass Frog (Espadarana / Centrolenella prosoblepon). Captive. Choc Region of northwest Ecuador.

Alex Hyde / Madagascar reed frog {Heterixalus madagascariensis} underside viewed through glass, Masoala Peninsula National Park, north east Madagascar.

Michael D. Kern / Zoo Atlanta / White-spotted leaf frog (Cochranella albomaculata) captive, from Central America. Please credit Michael Kern / Zoo Atlanta.

Edwin Giesbers / Ghost glass frog (Centrolenella ilex) portrait, Costa Rica

Michael D. Kern / Zoo Atlanta / White spotted glass frog {Cochranella albomaculata} portrait, captive, occurs Colombia, Costa Rica, Ecuador, Panama. Please credit Michael Kern / Zoo Atlanta.

Phil Savoie / Glass frog on heliconia flower. (Centrolenella fleischmanni) Belize

Pete Oxford / Glass frog {Hyalinobatrachium sp} Amazonia, SE Ecuador

Doug Wechsler / Pacific giant glass frog (Centrolenella geckoideum). NW Andes (2550m), Carchi Province, Ecuador, South America