Amphibians In Focus

Welcome to the Amphibians section of In Focus that delves into the fascinating world amphibians, including frogs, toads, and newts, are vital components of our ecosystems, serving as indicators of environmental health and playing crucial roles in food webs.

Amphibians are ectothermic, anamniotic vertebrates belonging to the class Amphibia, which includes frogs, toads, salamanders, and caecilians. As a group, they are paraphyletic, encompassing all tetrapods except amniotes ( reptiles, birds, and mammals). All extant amphibians belong to the subclass Lissamphibia, divided into three orders: Anura, Urodela, and Gymnophiona.

They are primarily semiaquatic and typically begin their life cycle as aquatic larvae (tadpoles) with gills, undergoing metamorphosis to become air-breathing adults with lungs. They rely on their skin for gas exchange and need access to water for breeding, making them ecological indicators of habitat conditions.

Evolving from lobe-finned fish in the Devonian period, they thrived during the Carboniferous and Permian periods but were later outcompeted by reptiles. Modern lissamphibians likely originated from temnospondyls during the Permian.

Currently, there are about 8,000 amphibian species, with nearly 90% being frogs. The smallest amphibian is the Paedophryne amauensis from New Guinea, measuring just 7.7 mm, while the largest is the South China giant salamander, which can reach 1.8 m. The study of amphibians is called batrachology, and the study of both reptiles and amphibians is known as herpetology.