Morley Read / Close-up of Agua rica leaf frog (Phyllomedusa ecuatoriana) eggs after 18 days development, the tadpoles are fully developed and ready to hatch, Ecuador. Endangered.

Morley Read / Close-up of Agua rica leaf frog (Phyllomedusa ecuatoriana) eggs after 11 days development, showing beating heart and blood flowing over gills, Ecuador. Endangered.

Morley Read / Close-up of an Amazon leaf frog (Cruziohyla Craspedopus) tadpole developing in egg, Ecuador. (non-ex)

Steve Downer / Timelapse of Common frog (Rana temporaria) tadpoles moving, UK, April. Captive.

Steve Downer / Timelapse of Common frog (Rana temporaria) tadpoles moving, UK, April. Captive.

Steve Downer / Common frog (Rana temporaria) underwater with frogspawn, UK, March. Controlled conditions

Steve Downer / Newly hatched Common frog (Rana temporaria) tadpoles feeding on egg cases, UK, March. Controlled conditions.

MYN / JP Lawrence / Lovely poison frog (Phyllobates lugubris) male with a tadpole, Isla Colon, Panama, June. Meetyourneighbours.net project

MYN / Paul van Hoof / Common spadefoot toad (Pelobates fuscus) composite showing metamorphosis from larva to adult, The Netherlands, meetyourneighbours.net project

Chris Mattison / Spotted reed frog (Hyperolius pucticulatus) tadpoles, captive, endemic to Tanzania.

Alastair MacEwen / Time-lapse of toadspawn from a Common toad (Bufo bufo) developing, emerging and feeding on nutrient jelly, Somerset, England, UK, April.

Alastair MacEwen / Close up time-lapse of frogspawn from a Common frog (Rana temporaria) developing, emerging and feeding on nutrient jelly, Somerset, England, UK, April.

Alastair MacEwen / Time-lapse of frogspawn from a Common frog (Rana temporaria) developing, Somerset, England, UK, April.

Barrie Britton / Wasp (Ropalidia species) attacking Mantellid Frog Tadpoles (Guibemantis species) on leaf overhanging pond. Tadpoles escape by dropping into water. Association Mitsinjo Reserve, Andasibe, Madagascar. P...

Barrie Britton / Mantellid Frog Tadpoles (Guibemantis species) developing on leaf overhanging pond. Association Mitsinjo Reserve, Andasibe, Madagascar. Photograph taken on location for BBC 'Wild Madagascar' Series, Fe...

Solvin Zankl / Lars Hendrickson watching Black piston water beetles (Hydrophilus aterrimus) feeding on a tadpole, State Collection in Munich, Germany, June

Philippe Clement / Common Frog (Rana temporaria) tadpole with limbs well developed but tail not yet reabsorbed, Belgium, captive

Solvin Zankl / Desert / Longtail tadpole shrimp {Triops longicaudatus}

Jane Burton / Common Frog (Rana temporaria) tadpoles developing in spawn

Kim Taylor / Great crested newt tadpole {Triturus cristatus} UK.

Barry Mansell / Pinewoods tree frog tadpole mimicing leaf {Hyla femoralis}

Fabio Liverani / Common tree froglet {Hyla arborea} tadpole with front and back legs, Italy

Fabio Liverani / Common tree frog {Hyla arborea} tadpole, Italy

Fabio Liverani / European Edible Frog froglets with tadpole tails. Italy

Fabio Liverani / Common tree frog tadpole with hind legs and front legs developing, Italy. Life cycle sequence 4

Fabio Liverani / Yellow bellied toad - eggs with developing embryos, Italy. Life cycle sequence 2

Adrian Davies / Common frog tadpole (Rana temporaria), semi albino (c. 7 weeks). England, UK, Europe

Jurgen Freund / Common frog tadpole in egg. (Rana temporaria) Germany

Pete Oxford / Marsupial Frog (Gastrotheca riobambae) tadpole, native to South America

Pete Oxford / Anthony's Poison Arrow Frog (Epipedobates anthonyi) male carrying tadpoles, native to South America

Michael & Patricia Fogden / Red-eyed Tree Frog (Agalychnis callidryas) tadpoles in rain water pond, Costa Rica

Piotr Naskrecki / Three-striped Poison Dart Frog (Ameerega trivittata) male carrying tadpoles, Suriname

Piotr Naskrecki / Three-striped Poison Dart Frog (Ameerega trivittata) male carrying tadpoles, Suriname

Mark Moffett / Golden Poison Dart Frog (Phyllobates terribilis) the most poisonous of the dart frogs, male carrying tadpoles on his back, Colombia

Mark Moffett / Strawberry Poison Dart Frog (Oophaga pumilio) mother deposits tadpoles, one by one, to pools of water in canopy bromeliad, scattering them among the trees, Bastimentos Island, Bocas del Toro, Panama

Robert Pickett / Common Frog, (Rana temporaria), tadpole with back leg developed, with tail, UK

Georgette Douwma / Common frog tadpoles (Rana temporaria) on a lily pad . London, UK, March.

Georgette Douwma / Common frog tadpoles (Rana temporaria) bunched up just under the surface of the pond, still with gills. London, UK, March.

Georgette Douwma / Common frog tadpoles (Rana temporaria) feeding on a tadpole. London, UK, May.

Georgette Douwma / Common frog tadpoles (Rana temporaria) feeding on a tadpole. London, UK, May.

Georgette Douwma / Common frog tadpoles (Rana temporaria) feeding on algae. London, UK, April.

Georgette Douwma / Common frog tadpoles (Rana temporaria) a lily pad. London, UK, April.

Georgette Douwma / Common frog tadpoles (Rana temporaria) bunched together under the surface of the pond. London, UK, April.

Georgette Douwma / Common frog tadpoles (Rana temporaria) in pond with duckweed. London, UK, April.

Georgette Douwma / Common frog tadpoles (Rana temporaria) in pond with duckweed. London, UK, April.

John Cancalosi / Green frog tadpole (Rana clamitans) intermediate stage tadpole with back legs, New York, USA

John Cancalosi / Green Frog (Rana clamitans) nearly metamorphosed frog showing remnants of tadpole tail, New York, USA

John Cancalosi / Green Frog (Rana clamitans) nearly metamorphosed frog showing remnants of tadpole tail, New York, USA