Amphibia

Amphibia is known as the cold-blooded vertebrate class of animals that can live on both land and underwater. These Amphibians went through dual life stages known as metamorphosis which first is the larvae stage in which they have gills and survive in water and the second stage is the terrestrial stage in which adults have lungs. Amphibia are found in diverse areas like deserts, rainforests, mountains, and woodlands. They are considered to be crucial for the maintenance of the life cycle of the ecosystem as these are insect predators.

What is Amphibia?

Amphibia is a class of vertebrate animals that belongs to the kingdom Animalia and phylum Chordata. Amphibians undergo a process known as metamorphosis that involves two distinct life phases. The first is the larval stage, during which they have gills and can only survive in water, and the second is the terrestrial stage, during which adults have lungs.

Characteristics of Class Amphibia

Amphibia are cold blooded vertebrates and have several characteristics features;

1. Moist Skin: They have thin and moist skin which makes them able to breath through skin as well. Their skin allows them them to exchange gases.
2. Metamorphosis: It is a crucial features of Amphibian which makes them to change from aquatic tadpole to terrestrial adult.
3. Dual Respiration: Amphibian have dual respiratory system including lungs and cutaneous skin while tadpoles have gills.
4. Ectothermic: They are not capable to regulate their body temperature from inside instead of that their body temperature depends upon surrounding environment.
5. Heart: They have three chambered heart including one ventricle and two artia.
6. Larvae stage: All Amphibian have dual life, first larvae then terrestrial adult.
7. Amphibious: They can survive in water as well as on terrestrial but they do require water for reproduction cycle.
8. External Fertilization: Basically female Amphibian laid eggs outside her body and male Amphibia have to pour their sperm over eggs to fertilize them.
9. Estivation and Herbination: Amphibia can undergo estivation in hot weather and herbination in cold weather to protect themselves in extreme conditions.
10. Carnivorous: They are carnivorous in nature i.e., feeds on insects.

Classification of Amphibian

They belong to class Amphibia and further divided into three sub categories which are as follows;

Order: Anura

Characteristics features

• They do not have tails as a adult
• They have strong vocalization
• They have four fostrong limbs to jump
• Fertilization occur outside the body
• Examples: Frogs and toads

Order Caudata

Characteristics features

• They have tails throughout their lives
• They have four legs
• Their skin is rough
• They can regenerate their body parts including limbs
• Examples: Salamenders and newts

Order: Gymnophinona or Apoda

Characteristics features

• They do not have legs
• Appearance is like snake or worm
• Segemented
• They are found below the surface
• They can secrete mucus to reduce water
• Examples: Caecilians

Anatomy and Physiology of Amphibia

Amphibia have unique anatomy and physiology because they live in water as well as on terrestrial surface;

Anatomical Features

1. Skin: Amphibia skin is soft, moist because they secrete mucus and they also exchange gases through skin.
2. Skeleton: They are vertebrates means have bone in their body and have limbs.
3. Muscular system: They have power hind limbs that allows them to jump.
4. Respiratory system: They have two lungs and gill to respirate. Tadpoles have gills while adult exchange gases through lungs and skin.
5. Cardiac system: Their hear is three chambered and have two artia and one ventricle.
6. Digestive system: They have two chambered stomach which allows them to store food and have simple digestive system.
7. Excetory system: They excrete through kidney and excretion waste mainly comprise of urea.
8. Reproduction: They mostly do external fertilization of eggs.

Physiological Features

1. Thermoregulation: Amphibians are ectothermic means they can not regulate temperature from inside.
2. Metamorphosis: They can transform themselves from aquatic larve stage to terrestrial adult.
3. Circulation: They have three chambered heart unlike mammals have four chambered heart.
4. Nervous system: Their nervous system is simple and have brain and spinal cord.
5. Sensory organs: They ear and eyes to sense surrounding environment.
6. Defence mechanisms: They posses poisons glands in skin through which they can secrete poison to kill predators. They can change their skin color to camouflage.

FAQs- Amphibia

1. Why is it called Amphibia?

Amphibians, named for their dual life, inhabit both water and land. The term “Amphibian” reflects their Greek origin, meaning a “double life.” Born with gills, they undergo transformations into adults, with some losing gills, while others retain them for life.

2. Is Snake an Amphibian?

Reptiles, such as snakes, turtles, and lizards, differ from Amphibians, including toads, frogs, and salamanders, as per Mass Audubon. A notable distinction lies in their association with water.

3. Name some Examples of Amphibians?

A diverse array of Amphibians populates the Earth, including frogs, salamanders, sirens, and hyla.

4. What is the difference between Amphibians and Reptiles?

Amphibians utilize gills for underwater breathing, while reptiles rely solely on lungs when on land. Amphibians feature soft, adhesive skin, whereas reptiles possess dry, scaly skin.

5. Do Amphibians lay Eggs?

All Amphibians lay eggs, and these eggs lack hard shells, requiring moisture for successful hatching. Typically, Amphibians deposit their eggs in water. For those laying eggs on land, special adaptations ensure the eggs remain sufficiently damp for proper development.