Frog, toad and newt tadpoles eat plants such as algae and pondweed or filter feed. When they get older, they may start to feed on tiny animals in the water. Salamander tadpoles and surinam horned toad tadpoles are carnivorous throughout their tadpole stage. Surinam horned toad tadpoles are very aggressive. They eat other tadpoles if food is nowhere to be found. The eggs of the spadefoot toad hatches in three days. Their tadpoles complete their metamorphosis in six to eight days. This is because spadefoot toads lay their eggs in places where water will dry up soon.
Tadpoles of frogs and toads start to grow their back legs first. They then grow front legs a few weeks later. When tadpoles grow their limbs they are called "froglets". This is because they look rather like a smaller version of adult frogs and toads. Tadpoles will also start to grow a backbone after growing their front limbs. After this, their mouths get bigger and their eyes will stick out more. After a tadpole has grown its hands, their tails continue to get shorter until there is nothing left of them.
Salamanders and newts can be found living in streams. Salamanders can be found in rotten logs, holes or underground places that are wet such as under leaves. Web-toed salamanders live in habitats where there are a lot of rocks. They like to hide under rocks and stones. The tailed frogs, like to live in cold water habitats. In their habitat, amphibians like to live where there are a lot of places to hide. These include nearby small trees, logs and plants. While underwater they like to hide near aquatic plants and rocks. Tree and dart frogs like to live in forests on trees, plants and on the ground under leaves.
Some amphibia can be found living in the desert or the arctic. The desert froglet lives in the desert. They are only active at night, when temperatures are much cooler. It rarely rains in the desert and because of this, desert frogs will burrow to keep cool. They use their mucus to keep them wet. They will spread it all over their bodies. The mucus will harden to keep the water it produces from escaping. Once the desert frog has done this, it will stay in its cocoon and will not move. They will stay like this for several months to years until a rainstorm. Desert frogs and toads lose water more quickly. The spadefoot toad will spit on the ground. Once they have done this, they will lay on it. Their bodies will take in the water. Their bodies are thin and have a lot of blood vessels, this helps them to be able to take water through their skin. The California newt can survive a fire by spreading its mucous over its body.
Arctic frogs such as the wood frog, moor frog and the common frog has to live with freezing temperatures for a long time. They will burrow in places where they can get into a cocoon. Like every living organisms, amphibians must have water to survive. Amphibians however, need freshwater. Some frogs such as burrowing frogs can keep water in their bladders. This allows them to stay underground without drying up. The crab-eating frog lives near water that is somewhat salty. They will eat saltwater crabs. Torrent salamanders lives in cold waters. Because of this they have shorter lungs. Short lungs helps them to float easily.
Amphibia are world-wide, though restricted in distribution by their need for moist or watery habitats to reproduce.
Many amphibia have secretions in their skin which makes them toxic. They do not produce toxins themselves. They get toxins from what they eat. They eat insects in their habitat. These insects get the poison from a plant. The toxin has been discovered in beetles. This means that they are likely the cause of poisons found in amphibians. Amphibians do not produce batrachotoxin in captivity, which means that it is not harmful to touch them. The American Indian tribe comechingóns used the toxins of the arrow dart frogs when hunting.
Newts in the genus "Taricha" has a poison called tetrodotoxin, a neurotoxin. Scientists believe that toxins in newts are caused by bacteria in the genera "Pseudoalteromonas", "Pseudomonas" and "Vibrio". Because of this, the newts do not have a lot of predators. However, some species of snakes have develop a resistance. This means that they can eat newts without the toxin hurting them. It is a case of co-evolution.
Amphibians' eyes have lids, glands and ducts. They have good colour vision Caecilian eyes are small and dark. Most of them are blind. Most amphibians have a good sense of smell, even underwater.
The skeletal system of amphibians are similar to other four-legged animals. They have a spine, rib cage, long bones such as the humerus and femur. They also have short bones such as the phalanges, metacarpals, and metatarsals. Most amphibians have four limbs, except for caecilians. The bones in amphibians are hollow and do not weigh much.
Amphibians are predatory animals. They mostly eat live invertebrates and animals that do not move too quickly. These include caterpillars, earthworms, crayfish, water beetles, snails and dragon fly larvae. Many amphibians use their sticky tongues to catch their prey. They will swallow the animal whole, but may chew it just a bit for it to go down their throats. The Ranidae family and the Ceratophrys genus will eat almost anything they can fit into their mouths. These include rodents, birds, ducklings, small fish and small mammals. Most frogs are cannibalistic, and will eat each other if food is no where to be found. Some amphibians will even eat their own tadpoles and eggs if there is no food for them.
In captivity, pet frogs will be given crickets, worms, small fish, rodents and fruit flies. Adult amphibians can help decrease the mosquito population by eating most of their larvae.
Caecilians eat earthworms, termites and beetle larvae, and also small lizards. Caecilians rely on their smell to find food. They like to eat earthworms and will find them by picking up their chemical signals. Salamanders and newts are fed a lot of different types of worms. These include blood worms and earthworms. They can eat small fish such as goldfish, fathead minnows and guppies. Salamanders also eat crickets and pinkies, which are baby rats.
The amphibian population have been decreasing from all locations in the world. Scientists have said that the declining of amphibians is one of the most critical threats to global biodiversity. A number of causes are believed to be involved. These include habitat destruction, over-exploitation, pollution, introduced species, climate change, destruction of the ozone layer, and diseases like chytridiomycosis. Ultraviolet radiation damages the skin, eyes and eggs of amphibians. However, the declines of amphibian population are still not understood.
The Amphibian Conservation Action Plan (ACAP) have released a global strategy to help the amphibian population. It was developed by over 80 leading experts. The Amphibian Specialist Group of the World Conservation Union (IUCN) are working on another global strategy to help amphibian populations. The Amphibian Ark (AA) is an organization that was created to help the public be aware of the decline in amphibian populations. They have been working with zoos and aquaria around the world. They try to encourage them to create a natural habitat for threatened amphibians. Another project is the Panama Amphibian Rescue and Conservation Project (PARCP) which are trying to spread awareness about chyridiomycosis. The disease is spreading into eastern Panama and threatening all amphibians living there.
On January 21, 2008, Evolutionarily Distinct and Globally Endangered (EDGE) released a statement to the public. It was created by Helen Meredith, who identified nature's most endangered species. Meredith explains that 85% of the top 100 endangered amphibians list are receiving little to no conservation attention.