Amphibians are an interesting group of animals with a distinct life cycle. They go through a number of changes from their early life to maturity — and experience physiological developments that are almost rare elsewhere in the animal kingdom. But what are amphibians and what types of amphibians are there? This article will review the category of amphibians as animals and provide a list of amphibians with facts.
What Is an Amphibian?
Amphibians are vertebrate animals that are cold-blooded (ectothermic) and have four limbs. Besides this, amphibians generally go through a life cycle that involves egg-laying (and hatching) in water and metamorphosis in their bodies — both inside and out.
Internally, the amphibian typically starts out with gills in its larval form, which change later to lungs — to achieve respiration in its adult form (amphibians can also breathe through their skin). Externally, amphibians may develop arms, legs, or lose their tails into adulthood.
All amphibians belong to the Amphibia class of animals, with Lissamphibia being the sub-class. There are about 8,000 species of amphibians in the world, and a vast majority of them (some ninety percent) are frogs.
As ectothermic animals that live near water, amphibians tend to live in warmer climates and mostly in freshwater areas. That said, some species exist in more northern climates (even as far north as Siberia and Alaska), and some can exist in woodland or underground areas.
Types of Amphibians
Scientifically, amphibians exist in three orders. These are the Apoda, Anura, and Urodela. The Apoda refers to a group of creatures known as Caecilians, which are worm-like amphibians found in tropical regions across several continents.
The Anura is a group of amphibians that consists of what are colloquially known as frogs and toads. There are some 5,000 species of Anura in the world and are known for their jumping ability, body shape, and life cycle that involves a transition from an egg, to a tadpole, and then to an adult.
The final group of amphibians in the Urodela, which consists of salamanders and newts. Unlike those of the Anura group, the Urodela are amphibians that keep their tails into adulthood. They lay their eggs in moist areas, have gills while young, and walk or swim (without jumping) as mature animals.
List of Amphibians
- Giant Salamanders
- Tree Frogs
- South Asian Frogs
- Poison Frogs
- Asiatic Salamanders
- True Frogs
- Pacific Giant Salamanders
- True Toads
- Mole Salamanders
Amphibians | Facts & Pictures
The South China Giant Salamander (Andrias sligoi) is an amphibian native to southern China, particularly the Pearl River region. This salamander can reach lengths in excess of five feet, five inches, and is considered to be the largest amphibian alive in the world today.
Tree frogs are a diverse group of some 800 frog species. They are distinguished by their toe morphology — which consists of a claw-like terminal phalanx, the final bone in their toes. Tree frogs can be less than an inch to over five inches long and exist on a diet of insects and other invertebrates.
Newts belong to the family Pleurodelinae, a sub-family of Urodela. Unlike salamanders, newts have bodies that consist of webbed feet and a tail that is often shaped like a paddle. Newts are a group of amphibians that live semi-aquatic lifestyles, salamanders merely breed and lay eggs in water.
South Asian Frogs
South Asian Frogs are more commonly referred to as Goose Frogs and are part of the family Megophryidae. They inhabit Indonesia, parts of Southeast Asia, southern China, Nepal, and the Philippines. They are noted for their leaf-like camouflage, with their skin at times pointed like leaf edges.
Mudpuppies are fairly large salamanders that are also known as Waterdogs. The Common Mudpuppy (Necturus maculosus) can grow to about 13 inches on average and is native to ponds, lakes, and rivers in eastern North America — dieting on mollusks, insects, and earthworms.
Poison Frogs are also known as Poison Dart Frogs, due to the fact that the toxins their skin secretes have historically been used to cover the tips of hunting darts. Inhabiting the Amazon rainforest and Central America, Poison Frogs are noted for their small size and extremely bright colors.
Caecilians are amphibians that are snake-like in appearance and inhabit areas of India, Africa, South, and Central America. They are burrowing animals and live under leaves and soil. Caecilians have a recessed mouth, long bodies, no legs, and strong jaws — and feed on snakes, insects, and worms.
Asiatic Salamanders are salamanders that belong to the Hynobiidae family. They are common to Asia, with about half of the species found exclusively in Japan. They are related to Giant Salamanders and can inhabit countries such as China, Russia, Iran, Japan, and Afghanistan.
True Frogs are a category of frogs that consist of some 600 species of the family Ranidae. They are noted for having webbed toes, long legs, and a bony chest bone. The Bullfrog (Lithobates catesbeianus) is a large species of True Frog native to eastern North America.
Pacific Giant Salamanders
Pacific Giant Salamanders are salamanders that belong to the Dicamptodon genus. They are fairly large salamanders that can grow up to a foot in length. There are four main species of Pacific Giant Salamander (Coastal, California, Cope’s, and Idaho) and live in the Pacific Northwest.
True Toads belong to the Bufonidae family of amphibians and consist of some 500 species. They are noted for having bumpy, warty skin, short legs, and parotoid glands on the sides of their heads — glands that are used to secrete predator-deterring neurotoxins.
Mole salamanders are a group of salamanders that belong to the family Ambystoma. They are known for burrowing holes (or using the holes of other animals) for hibernation purposes. The Spotted salamander (Ambystoma maculatum) is the state salamander of South Carolina and Ohio.
Sirens are native to the southeastern United States and the Mississippi River. They are long, snake-like salamanders that have short front legs, gills, and gill slits, even as adults. They have no hind legs and feed on plants and insects.