Searching in Birkbeck, University of London, Greater London, England
are diverse amphibians with over 7,500 species, characterized by strong hind legs for leaping and swimming, permeable skin for water absorption and breathing, and the ability to catch prey with sticky tongues. They begin as aquatic tadpoles that undergo metamorphosis into their adult form, and many species can absorb toxins, making them sensitive environmental indicators of pollution.