Amphibians – Characteristic Features

What are Amphibians

Amphibians are a class of around 7,000 species found across the world, with 90% of them being frogs. The largest recorded amphibian is the Chinese giant salamander, while the microhylid family of frogs from New Guinea is considered the smallest. Most members of this class are insectivores, playing an important part in the ecosystem by keeping insect populations in check.

Unique Features

Skeletal System

All amphibians are vertebrates, belonging to the Chordata phylum.

Amphibian Skeleton


Cold-blooded, also known as ectothermic, meaning they cannot regulate their body-temperature.

Amphibians Cold Blooded



Tetrapod, that is adults have four limbs, except for caecilians, the only limbless amphibian order.

Amphibian Types


Semi-aquatic in nature, at least a part of their lives in spent in water.

Amphibian Habitat

Reproductive Process

The process using which they mate is called amplexus. The male grasps onto the females head, armpit or waist and as the female’s eggs come out of her body, they are fertilized by the males.

Amphibian Eggs

Life Cycle – Metamorphosis

Most of them undergo metamorphosis, wherein they transform from a gilled larva into an adult that breathes air with lungs.

Amphibian Life Cycle

Feeding Habit

Most of them flick out their elongated and sticky tipped tongue to catch their prey.

Amphibian Feeding

Circulatory System

There are three chambers in their heart – one ventricle and two atria. Apart from the two regular circuits, one to pump the blood between the heart and lungs, and another to pump the blood between the heart and the rest of the body, amphibians have a third circulatory route that carries deoxygenated blood to their skin for gas exchange (pulmocutaneous circulation).

Amphibian Heart

Skin Characteristics

Soft, moist, glandular, and permeable skin, sometimes used by as a secondary means of respiration. Some species, in fact, lack lungs altogether and use their skin as the primary tool for respiration.

Amphibian Skin