salamander

Salamanders are a group of amphibians in the order Caudata (also called Urodela). They typically have elongated bodies, moist smooth skin, and a long tail, with four legs of similar size; some aquatic forms are more eel-like. Size ranges from a few centimeters to well over 30 centimeters. Many salamanders respire in part through the skin, and several lineages, notably the lungless salamanders (Plethodontidae), lack lungs entirely.

They are distributed mainly in the temperate regions of the Northern Hemisphere, with diverse groups in North America, Europe, and Asia; a number of tropical species occur in Central and South America and parts of Asia. They inhabit forests, streams, wetlands, and underground habitats, requiring moist conditions to prevent desiccation.

Reproduction and development vary widely. Most species lay eggs in moist or aquatic environments; some give birth to live young. Fertilization is typically internal, accomplished by males depositing a spermatophore that females pick up. Larval stages often have external gills and aquatic habits, but many species undergo metamorphosis or exhibit direct development on land.

Ecology: Salamanders are primarily carnivorous, feeding on invertebrates such as insects, worms, and crustaceans. They are both predators and prey in many ecosystems and are often sensitive indicators of environmental health.

Conservation and threats: Habitat destruction, pollution, climate change, and disease—particularly chytrid fungi such as Batrachochytrium dendrobatidis and B. salamandrivorans—have imperiled numerous species. Some salamander populations are legally protected or subject to captive breeding programs.

Notable species: The axolotl (Ambystoma mexicanum) is renowned for neoteny, retaining larval features into adulthood. The olm (Proteus anguinus) is a cave-dwelling European salamander with reduced vision.