Amphibians: Frogs, Salamanders, Newts, And Caecilians
Amphibians are vertebrates in class Amphibia. Living amphibians include three main groups: frogs and toads, salamanders and newts, and caecilians.
What Amphibians Are
Amphibians are living members of class Amphibia. Modern amphibians are grouped into frogs and toads, salamanders and newts, and caecilians. They are not reptiles, even when they share wetlands, forests, or underground habitat with reptiles.
Many amphibians are famous for life between water and land, but the real picture is wider. Some species have aquatic larvae and terrestrial adults, some remain aquatic, some burrow underground, and some develop directly without a free-swimming tadpole stage.
The Three Living Groups
Frogs and toads are order Anura. They are tailless as adults and include tree frogs, true frogs, true toads, poison frogs, glass frogs, narrow-mouthed frogs, and many other families.
Salamanders and newts are order Caudata. They keep tails as adults and include lungless salamanders, mole salamanders, giant salamanders, newts, sirens, and amphiumas. Caecilians are order Gymnophiona, a group of mostly limbless, often burrowing amphibians that many casual readers have never seen.
Skin, Water, And Life Cycles
Amphibian skin is usually moist and permeable, which helps with water balance and gas exchange but also makes many species vulnerable to drying, chemicals, and pathogens.
Eggs often lack the hard shells found in birds and many reptiles. Many species lay eggs in water or damp places, hatch into larvae, and later metamorphose. Others guard eggs, carry young, use foam nests, lay eggs on leaves, or hatch as small versions of adults.
Ecological Role
Amphibians eat insects, worms, small crustaceans, slugs, snails, and many other small animals. Tadpoles can graze algae, filter organic material, or feed in specialized ways depending on species.
They are also prey for birds, fish, snakes, mammals, larger amphibians, and invertebrate predators. By moving nutrients between water and land, amphibians help connect ponds, streams, forests, meadows, and underground food webs.
Conservation
IUCN reported in 2024 that nearly 41 percent of amphibian species are at risk of extinction based on the Second Global Amphibian Assessment. That makes amphibians a major warning signal for freshwater and forest health.
Important threats include habitat loss, chytrid disease, ranaviruses, pollution, climate change, invasive species, road mortality, and careless movement through pet release or pond-to-pond transfer. The best public help is clean water, connected native habitat, reduced pesticide use, and no release or relocation.