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

Pete Oxford / Glass frog with eggs visible through skin {Centrolenella sp} Ecuador, South America

Phil Savoie / Glass frog guarding its eggs (Centrolenella fleischmanni) Belize

Phil Savoie / Glass frog parent guarding eggs (Centrolenella fleischmanni) Belize

Doug Wechsler / Glass frog in rainforest understorey, Ecuador

Morley Read / Glass frog (Centrolenidae) tadpoles developing in an egg mass, Cordillera del Condor, Zamora Chinchipe Province, Ecuador. (non-ex)

Morley Read / Glass frog (Centrolenidae) tadpoles developing in an egg mass, Cordillera del Condor, Zamora Chinchipe Province, Ecuador. (non-ex)

Morley Read / Glass frog (Centrolenidae) tadpoles developing in an egg mass, Cordillera del Condor, Zamora Chinchipe Province, Ecuador. (non-ex)

Morley Read / Glass frog (Espadarana) tadpoles developing in an egg mass, Cordillera del Condor, Zamora Chinchipe Province, Ecuador. Endangered. (non-ex)

Morley Read / Glass frog (Espadarana) tadpoles developing in an egg mass, Cordillera del Condor, Zamora Chinchipe Province, Ecuador. Endangered. (non-ex)

Morley Read / Glass frog (Espadarana) tadpoles developing in an egg mass, Cordillera del Condor, Zamora Chinchipe Province, Ecuador. Endangered. (non-ex)

Lucas Bustamante / Minute Glassfrog (Centrolene peristictum) male guarding eggs, Mindo, Pichincha, Ecuador, Vulnerable species.

Lucas Bustamante / Two Yellow-flecked glass frogs / White-spotted cochran frogs (Sachatamia albomaculata) on branch, Canande, Esmeraldas, Ecuador.

Lucas Bustamante / Las Gralarias Glassfrog (Nymphargus lasgralarias) spawn with tadpoles developing in eggs hanging from leaf, Mindo, Pichincha, Ecuador.

Ingo Arndt / Glass frog on rainforest leaf {Hyalinobatrachium sp} Costa Rica

Ingo Arndt / Glass frog on rainforest leaf {Hyalinobatrachium sp} Costa Rica

Alex Hyde / Fleischmann's glassfrog (Hyalinobatrachium fleischmanni) male attending eggs on the underside of a leaf overhanging a rainforest stream, the male will occasionally sit on the egg mass and empty his bl...

Alex Hyde / Ghost glass frog (Sachatamia ilex) Central Caribbean foothills, Costa Rica

Pete Oxford / Glass frogs (Hyalinobatrachium aureoguttatum) two backlit on leaf, captive, occurs in Ecuador, Colombia, and Panama.

Pete Oxford / Glass frogs (Hyalinobatrachium aureoguttatum) two on leaf, captive, occurs in Ecuador, Colombia, and Panama.

Denis-Huot / Glassfrog (Centrolenidae sp) Manuel Antonio National Park, Costa Rica

Bert Willaert / Glass frogs (Cochranella mache) in amplexus. Ecuador, Endangered species.

Bert Willaert / Glass Frogs (Cochranella mache) in amplexus. Ecuador, Endangered species.

Bert Willaert / Glass Frogs (Cochranella mache) in amplexus. Ecuador, Endangered species.

Bert Willaert / Glass Frogs (Cochranella mache) on leaf, Ecuador, Endangered species.

Bert Willaert / Glass Frogs (Cochranella mache) on leaf, Ecuador, Endangered species.

Bert Willaert / Glass Frog (Cochranella mache) portrait, Ecuador, Endangered species.

Bert Willaert / Glass Frog (Cochranella mache) portrait, Ecuador, Endangered species.

Bert Willaert / Glass Frog (Cochranella mache) on leaf, Ecuador, Endangered species.

Bert Willaert / Glass Frog (Cochranella mache) on leaf, Ecuador, Endangered species.

Bert Willaert / Glass Frog (Cochranella mache) on leaf, Ecuador, Endangered species.

MYN / Alfonso Lario / White spotted glass frog (Cochranella / Teratohyla albomaculata) tropical rainforest, Burbayar, Panama, November. meetyourneighbours.net project

Roland Seitre / Giant Glass Frog (Sachatamia / Centrolene ilex) El Valle Amphibian Conservation Center, Panama, Central America

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

Pete Oxford / Spiny Cochran Glass Frog Eggs (Teratohyla spinosa). Choco Region of north western Ecuador. South America.

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

Pete Oxford / Glass Frog (Hyalinobatrachium aureoguttatum) eggs. Captive. Chocó Region of northwest Ecuador on Colombian Border, Ecuador.

Pete Oxford / Spiny Cochran Glass Frog Eggs (Teratohyla spinosa). Choco Region of north western Ecuador. South America.

Nature Production / Japanese tree frog (Hyla japonica) close up of foot and toes through glass, Japan

Nature Production / Japanese tree frog (Hyla japonica) climbing up glass with raindrops, Japan

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

PREMAPHOTOS / Fleischmann's glass frog (Centrolenella / Hyalinobatrachium fleischmanni) in daytime resting pose in cloud forest, Panama

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

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

Nick Gordon / Glass frog {Centrolenella sp} in bromeliad, Amazonia, Brazil

Doug Wechsler / Common dink frog viewed through glass {Eleutherodactylus diadematus} Costa Rica

Philippe Clement / Grainy Cochran Frog / Granular Glass Frog {Cochranella granulosa} Costa Rica.

Philippe Clement / Grainy Cochran Frog / Granular Glass Frog {Cochranella granulosa} on leaf, Costa Rica

Philippe Clement / Grainy Cochran Frog / Granular Glass Frog {Cochranella granulosa} resting on leaf, Costa Rica.

Philippe Clement / Grainy Cochran Frog / Granular Glass Frog {Cochranella granulosa} on leaf, Costa Rica

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

Pete Oxford / Underside of Glass frog {Hyalinobatrachium sp} internal organs visible. Ecuador

Pete Oxford / Underside of Glass frog {Centrolenella sp} Ecuador

Doug Wechsler / Close up of foot of Glass frog showing pads {Centrolenella sp} Ecuador

Doug Wechsler / Fleischmann's glass frog calling {Hyalinobatrachium fleischmanni} male, Panama

Doug Wechsler / Male Glass frog calling {Hyalinobatrachium sp} Panama

Doug Wechsler / Fleischmann's glass frog calling {Hyalinobatrachium fleischmanni} male, Panama.

Doug Wechsler / Male Glass frog calling {Hyalinobatrachium sp} Panama

Doug Wechsler / Emerald glass frog underside {Centrolenella prosoblepon} Rio San Carlos, Costa Rica

Doug Wechsler / Emerald glassfrog female {Centrolenella prosoblepon} Costa Rica Rio San Carlos

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

Doug Wechsler / Glass Frog (Centrolenella midas) River Napo, Ecuador

Pete Oxford / Glass frog (Centrolenella sp) Ecuador, South America

Emanuele Biggi / La Palma glass frogs (Hyalinobatrachium valerioi) mating pair, on a leaf with egg-clutches from previous matings nearby. The males stay and defend the eggs, even mimicking them in colouration to act a...

Roman Willi / Reticulated glass frogs (Hyalinobatrachium valerioi) pair in amplexus, Osa Peninsula, Costa Rica.