Mary Allen
Amphibians (from the ancient Greek amphibium = double-lived), also known as amphibians, are cold-blooded animals and are considered to be the oldest taxon of land-living vertebrates. The first amphibians appeared around 400 million years ago in the Devonian geological era. Almost all amphibians go through a so-called metamorphosis during their lifetime, which means that their shape changes. A simple example of this is the frog. Tadpoles develop first from the fertilized spawn. In this context one also speaks of the larval form. Over the weeks, the tadpole grows and, in several steps, turns into a frog. With the completion of the metamorphosis, the former larval form has become an adult animal. From this point on, the amphibian is then in the adult stage (adult = adult).
Most amphibians also change their habitat with the completed metamorphosis. Tadpoles are purely water dwellers with gill breathing. Frogs breathe through their lungs, which develop during metamorphosis. For this reason, amphibians represent the link, so to speak, between aquatic and terrestrial species. Vertebrates probably came ashore from a preform of today’s amphibians, which evolved from bony fish.
Existing amphibians are divided into three orders:
- Frogs: e.g. frogs, toads;
- Tailed amphibians: including newts, olm, axolotl, and salamander;
- Creeping amphibians: including ringworm.
Characteristics of amphibians:
Amphibians (amphibians) have some characteristics that are absolutely typical for this class of vertebrates. In particular, this includes the ability to metamorphosis, the presence of a cloaca, or poikilothermy. In individual cases, it may happen that not all of the characteristics listed here apply to an amphibian species. For example, not all amphibians necessarily have venom glands or a particularly well-developed sense of sight.
Respiration: As a larva, respiration takes place via the gills, later in the adult stage via the lungs.
Limbs: Amphibians have a total of four limbs (two front legs, two hind legs). In some species, the extremities appear in a stunted form.
Reproduction: The eggs are fertilized outside in the water. That means there is no copulation like in mammals.
Venom: Many amphibian species have venom glands on their skin.
Skin respiration: A small proportion of the required oxygen can be absorbed through the skin of the amphibian.
Cloaca: Amphibians only have a single exit for the urethra and anus, the so-called cloaca.
Spawn: The larvae of the amphibian hatch from the spawn.
Habitat: Amphibians can live both in water and on land. Essentially depends on the stage of development of the amphibian.
Metamorphosis: Amphibians undergo development (metamorphosis) from larva to adult. In the process, most amphibian species change from aquatic animals to terrestrial animals.
Poikilothermy: All amphibians are cold-blooded. Your body temperature depends on the ambient temperature.
Slime glands: The skin of amphibians is constantly moistened by special slime glands.
Senses: Almost all amphibians have a good sense of sight. They react particularly strongly to movement stimuli.
Vertebrates: As vertebrates, adult amphibians have a spine.
What are examples of amphibians?
Cane toad, axolotl, fire salamander, frog, gecko, olm, tree frog, newt, poison dart frog, smooth newt, toad, sand lizard.
Amphibians are the oldest taxon of terrestrial vertebrates.
Amphibians go through a metamorphosis: from the larval form to the adult stage.
With completed metamorphosis, most amphibians have also changed their habitat (from water to land).
What is the difference between amphibians and reptiles?
Amphibians prefer rather humid habitats, avoid the sun and move slowly on land. They do not drink, but absorb liquid through their skin, which is usually moist. Reptiles are rather heat-loving, like to sunbathe and actively drink water. Their horny skin is always dry.
Are amphibians warm- or cold-blooded?
All amphibians are ectotherms (what used to be called “cold-blooded”), a trait they share with invertebrates, fish, and reptiles.
What is the largest amphibian species in the world?
The world’s largest amphibian – the Chinese giant salamander (Andrias davidianus, pictured) -should be split into at least five species, all of which are critically endangered in the wild, according to a new study.
Are crocodiles classified as amphibians or reptiles?
Reptiles are turtles, snakes, lizards, alligators, and crocodiles. Unlike amphibians, reptiles breathe only through their lungs and have dry, scaly skin that prevents them from drying out. Amphibians and reptiles are together called herpetofauna, or “herps” for short.
What is the difference between mammals and amphibians?
Mammals give birth to live young, whereas the birth of amphibians takes place externally. Mammals are warm-blooded, while amphibians are cold-blooded. Mammals can live in all habitats, unlike amphibians, and have muted colors. Some amphibians can regenerate their limbs.
Is a turtle a reptile or amphibian?
Turtles are popular pets. Their good-natured, slow-moving nature and big eyes make turtles appear cute. But they are and will remain reptiles. They hardly have any enemies.
How do amphibians differ from fish?
Because the primeval vertebrates (jawless) and the first vertebrates, the fish, can only live in water. The amphibians form a transitional state and the following three classes are independent of water. An exception to this are some mammals, such as the whale, which have returned to the water.
What is the smartest amphibian?
In fact, among the amphibians, the anurans, or frogs and toads, are perhaps the most intelligent, and have the largest brain to body ratio of the amphibians.
How do amphibians breathe?
Most amphibians breathe through lungs and their skin. Their skin has to stay wet in order for them to absorb oxygen so they secrete mucous to keep their skin moist (If they get too dry, they cannot breathe and will die).
What is the difference between reptiles, amphibians, and mammals?
Amphibians and reptiles are cold-blooded animals. Their metabolic activity increases and decreases with the ambient temperature. Mammals, on the other hand, are warm animals. Your respiratory system is geared towards constantly high metabolic performance.