Gary Bell/ Oceanwide / Veined Octopus (Octopus marginatus) hiding in glass jar, Lembeh Strait, Indonesia

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

Phil Savoie / Reticulated glass frog (Hyalinobatrachium valerioi) La Selva Field Station, Costa Rica.

Lucas Bustamante / Coastal glassfrog (Cochranella litoralis) on leaf with eggs. San Lorenzo, Esmeraldas, Ecuador.

Nick Garbutt / Montane Glass Frog (Centrolenella ilex) inside curled leaf. Mid-altitude rainforest, Bosque de Paz, Pacific slope, Costa Rica, Central America.

Nick Garbutt / Emerald Glass Frog (Centrolenella proseblepan) on leaf. Mid-altitude rainforest, Bosque de Paz, Pacific slope, Costa Rica, Central America.

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

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

Alex Hyde / Spined glassfrog (Teratohyla spinosa) Central Caribbean foothills, Costa Rica.

Edwin Giesbers / Reticulated glass frog (Hyalinobatrachium valerioi) captive, occurs in Colombia, Costa Rica, Ecuador, and Panama

Pete Oxford / Glass Frog (Hyalinobatrachium aureoguttatum) pair, native to South America

Pete Oxford / Glass Frog (Hyalinobatrachium aureoguttatum) underside showing internal organs, native to South America