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. (non-ex)

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. (non-ex)

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.

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.

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

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