Amphibian Types - Characteristics, Names and Examples

Content

• What is an amphibian?
• Amphibian Characteristics
• Types of amphibians and their names
• Cecilia or Apoda (Gymnophiona)
• Salamanders and Newts (Urodela)
• Frogs and Toads (Anura)
• Examples of amphibians
• Amphibian Curiosities
• animal aposematism
• paedomorphosis
• Endangered amphibians

The name of amphibians (amphi-bios) comes from the Greek and means "both lives". That's because its life cycle elapses between water and land. These strange creatures alter their way of life and appearance throughout their development. Most are nocturnal and poisonous. Some even gather to sing on rainy nights. Without a doubt, they are one of the most interesting vertebrate animals.

Currently, more than 7,000 species of amphibians have been described, distributed almost all over the world, except in the most extreme climates. However, due to their peculiar way of life, they are much more abundant in the tropics. Do you want to get to know these animals better? So don't miss this PeritoAnimal article about the different types of amphibians, their characteristics, names and examples curious.

What is an amphibian?

Current amphibians (class Amphibia) are animals non-amniote tetrapod vertebrates. This means they have a bony skeleton, have four legs (hence the word tetrapod) and lay eggs without protective membranes. Due to this last fact, their eggs are very sensitive to dryness, and must be placed in water. From these eggs, aquatic larvae emerge that later undergo a transformation process known as metamorphosis. This is how amphibians become semi-terrestrial adults. A clear example of this is the life cycle of frogs.

Despite their apparent fragility, amphibians have colonized much of the world and adapted to different ecosystems and habitats. For this reason, there are many types of amphibians with enormous diversity. This is due to the large number of exceptions that do not conform to the definition we presented above.

Amphibian Characteristics

Due to their great diversity, it is very difficult to indicate what different types of amphibians have in common. However, we have gathered its most important features, indicating which ones have exceptions. These are the main characteristics of amphibians:

• tetrapods: With the exception of Cecilias, amphibians have two pairs of limbs that end in legs. Paws usually have webs and 4 toes, although there are many exceptions.
• FORhe sensitive: They have very thin skin, without scales and sensitive to dryness, which is why it should always remain moist and at a moderate temperature.
• toxic: Amphibians have glands in their skin that produce defensive substances. For this reason, your skin is toxic if ingested or if it comes in contact with your eyes. However, most species pose no threat to humans.
• skin breathing: Most amphibians breathe through their skin and therefore always keep it moist. Many amphibians supplement this type of breathing with the presence of lungs, and others have gills throughout their lives. You can learn more about this subject in the article on where and how amphibians breathe.
• Ectothermy: body temperature depends on the environment in which amphibians are found. For this reason, it is common to see them sunbathing.
• sexual reproduction: amphibians have separate sexes, that is, there are males and females. Both sexes mate for fertilization to occur, which can be inside or outside the female.
• oviparous: females lay aquatic eggs with very thin gelatinous coatings. For this reason, amphibians depend on the presence of water or moisture for their reproduction. Very few amphibians have adapted to arid environments thanks to the development of viviparity, and these do not lay eggs.
• indirect development: from eggs hatch aquatic larvae that breathe through gills. During their development, they undergo a metamorphosis that can be more or less complex, during which they acquire the characteristics of adults. Some amphibians show direct development and do not undergo metamorphosis.
• nighttime: Most amphibians are most active at night, when they hunt and breed. However, many species are diurnal.
• Carnivores: amphibians are carnivores in their adult state and feed mainly on invertebrates. Despite this, their larvae are herbivores and consume algae, with few exceptions.

As we've already mentioned, another of the main characteristics of amphibians is that they go through a transformation process called metamorphosis. Below, we show a representative image of the amphibian metamorphosis.

Types of amphibians and their names

There are three types of amphibians:

• Cecilias or apodas (order Gymnophiona).
• Salamanders and newts (order Urodela).
• Frogs and toads (order Anura).

Cecilia or Apoda (Gymnophiona)

Cecilias or Apoda are about 200 species distributed in the tropical forests of South America, Africa and Southeast Asia. They are vermiform amphibians, that is, of elongated and cylindrical shape. Unlike other types of amphibians, Cecilias have no legs and some have scales on their skin.

these strange animals live buried in moist soiltherefore many are blind. Unlike anurans, males have a copulatory organ, so fertilization takes place inside the female. The rest of the reproductive process differs a lot in each family and even in each species.

Salamanders and Newts (Urodela)

The order of Urodelos includes about 650 species. These animals are characterized by having a tail throughout their lives, that is, larvae do not lose their tail during metamorphosis. Also, its four legs are very similar in length; therefore, they move by walking or climbing. Like caecilians, fertilization of eggs takes place inside the female through copulation.

The traditional division between salamanders and newts has no taxonomic value. However, species that have a primarily terrestrial way of life are often called salamanders. They usually inhabit moist soils and only migrate to water to reproduce. Meanwhile, newts spend a lot more time in the water.

Frogs and Toads (Anura)

The name "a-nuro" means "tailless". This is because the larvae of these amphibians, known as tadpoles, lose this organ during metamorphosis. Thus, adult frogs and toads do not have tails. Another differential feature is that its hind legs are longer than the forelegs, and they move by jumping. Unlike other types of amphibians, fertilization of eggs takes place outside the female.

As with urodelos, the differences between toad and frog are not based on genetics and taxonomy, but on human perception. The more robust frogs are known as toads, and they generally have more earthy habits, which makes their skin drier and more wrinkled. Frogs, on the other hand, are graceful looking animals, skilled jumpers and sometimes climbers. Their way of life is usually more associated with aquatic environments.

Examples of amphibians

In this section, we show you some examples of amphibians. Specifically, we selected some of the curious species. This way, you will be able to better understand the highly variable characteristics that appear in different types of amphibians.

• Mexican Cecilia or tappease (Dermophis mexicanus): these caecilians are viviparous. Their embryos develop inside the mother for several months. There, they feed on internal secretions produced by the mother.
• Cecilia-de-Koh-Tao (Ichthyophis kohtaoensis): is a Thai cecilia that lays its eggs on the ground. Unlike most amphibians, the mother takes care of the eggs until they hatch.
• anphiumas (Amphiumaspp.): there are three species of very elongated, cylindrical and vestigial-legged aquatic amphibians. A. tridactylum has three fingers, A. means has two and A. pholeter own only one. Despite their appearance, they are not caecilians but urodelos.
• Proteus (Proteus anguinus): this urodelo is adapted to live in the darkness of some European caves. For this reason, adults have no eyes, are white or pink – and live in water all their lives. In addition, they are elongated, flat-headed, and breathe through gills.
• Protruding Ribs Salamander (pleurodeles walt): is a European urodelo that can reach 30 centimeters in length. On the side of his body, there is a row of orange spots that coincide with the edges of his ribs. When they feel threatened, they highlight them, threatening their potential predators.
• Hairy Frog (Trichobatrachus robustus): Despite their appearance, furry frogs do not have hairs, but rather stretches of vascularized skin. They serve to increase the surface area of ​​gas exchange so that more oxygen can be absorbed.
• Surinan Toad (kite kite): This Amazon frog is characterized by having an extremely flat body. Females have a type of net on their back, in which they sink and trap eggs during copulation. From these eggs emerge not larvae but young frogs.
• Nimba's Toad (Nectophrynoidsoccidentalis): is a livebearing African frog. Females give birth to offspring that look the same as an adult. Direct development is a reproductive strategy that allows them to be independent of water bodies.

Amphibian Curiosities

Now that we know all kinds of amphibians, let's look at some of the more interesting features that appear in some species.

animal aposematism

Many amphibians have very flashy colors. They serve to inform potential predators about their venom. These predators identify the intense color of amphibians as a danger, and so do not eat them. Thus, both avoid hassles.

A very curious example is the fire-bellied toads (Bombinatoridae). These Eurasian amphibians are characterized by having heart-shaped pupils and red, orange or yellow bellies. When disturbed, they turn or show the color of the underside of their feet, adopting a posture known as an "unkenreflex". In this way, predators observe color and associate it with danger.

The best known are the arrowhead frogs (Dendrobatidae), very venomous and flashy frogs that live in neotropical regions. You can learn more about aposematic species in this article about animal aposematism, including other types of amphibians.

paedomorphosis

Some urodels have paedomorphosis, that is, keep their youthful characteristics as adults. This occurs when physical development diminishes, so that sexual maturity appears when the animal still has a larval appearance. This process is known as neoteny and is what happens in the Mexican axolotl (Ambystoma mexicanum) and in the Proteus (Proteus anguinus).

Pedamorphosis can also occur due to acceleration of sexual maturity. In this way, the animal acquires the ability to reproduce when it still has a larval appearance. It is a process known as progenesis and occurs in species of the genus Necturus, endemic to North America. Like the axolotl, these urodels retain their gills and live permanently in water.

Endangered amphibians

About 3,200 amphibian species are in danger of extinction, that is, nearly half. In addition, it is believed that more than 1,000 endangered species have yet to be discovered due to their rarity. One of the main threats to amphibians is the chytrid fungus (Batrachochytrium dendrobatidis), which has already extinguished hundreds of species.

The rapid expansion of this fungus is due to the human actions, such as globalization, animal trafficking and irresponsible pet liberation. In addition to being disease vectors, exotic amphibians quickly become invasive species. They are often more voracious than native species, and drive them away from their ecosystems. This is the case of the African clawed frog (Xenopus laevis) and the American bullfrog (Lithobates catesbeianus).

To make matters worse, the disappearance from their habitats, such as freshwater bodies and rainforests, is causing amphibian populations to decline. This is due to climate change, deforestation and direct destruction of aquatic habitats.

If you want to read more articles similar to Amphibian Types - Characteristics, Names and Examples, we recommend that you enter our Curiosities section of the animal world.