Amphibians Body Parts and Habitat

About Amphibians

• Amphibians are small vertebrates that need water or a moist environment to survive.
• They are cold-blooded and breathe and absorb water through their very thin skin.
• The species in this group include frogs, toads, salamanders, and newts.

Body Parts

• Amphibians have four limbs, with the front limbs being elongated and modified for jumping.
• Their head and trunk are fused together, and they have a tail that is present only in the larval stage.
• They have a smooth skin with poison glands.

Reproductive System

• Amphibians reproduce through sexual reproduction.
• Fertilization in frogs is generally external, while in salamanders and caecilians it is internal.
• Some frogs lay their eggs in the wild and do not require a water medium to breed and lay their eggs.
• Salamanders and caecilians use internal fertilization, and the males emit an odor, display colors and postures to attract females.

Habitat

• Amphibians can be found in forests, woodlots, meadows, springs, streams, rivers, lakes, ponds, bogs, marshes, swamps, vernal ponds, and farmlands.
• They require very specific living conditions, and too much sun can damage their cells, while too much wind can dry their skin and dehydrate the animal.

Class of Amphibians

• There are three classes of amphibians: Anuras, Caudata, and Caecilians.
• Anuras include around 3400 species, and have four limbs, with the front limbs being elongated and modified for jumping.
• Caudata have a tail, elongated body, and four equally sized limbs, and are found under leaf litter, in the soil, or in water.
• Caecilians are also known as "blind-worms" and have venom glands, secreting mucus to reduce water loss.

Mobility

• Anuras have a leaping movement that requires complex pectoral and pelvic girdles, and they also have structures that allow them to climb trees.
• Caudata have a generalized mode of locomotion, walking and moving their limbs in a standard diagonal-sequence gait of quadrupeds.
• Caecilians move using concertina locomotion, where the body alternately folds and extends itself along its entire length.

Organ System

• Amphibians have digestive, excretory, and reproductive systems that share a body cavity called cloaca.
• They have a complex circulatory system with a three-chambered heart.
• They also have a nervous system that allows them to interact with each other and their environment.
• Amphibians have sense organs to smell and taste chemicals, and other sense organs include eyes and ears.