Animals Classification
Animals have several characteristics that set them apart from other living things. There are many different types of animals in the world.


Amphibians are cold-blooded vertebrate of the class Amphibia, comprising frogs and toads, newts and salamanders, and caecilians, Amphibians typically start out as larva living in water. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely upon skin.

Amphibians are ectothermic (cold-blooded) vertebrates that do not maintain their body temperature through internal physiological processes. Their metabolic rate is low and as a result, their food and energy requirements are limited.
They have muscular tongues,their ribs are usually short and may be fused to the vertebrae, their skulls are mostly broad and short,their skin contains little keratin and lacks scales.

The hearts of amphibians have three chambers, two atria and one ventricle.They all have four limbs except for the legless caecilians and a few species of salamander with reduced or no limbs. The bones are hollow and lightweight.

Paedophryne Amauensis
Chinese Giant Salamander
The smallest amphibian and vertebrate in the world is a frog from New Guinea "Paedophryne amauensis" with a length of just 7.7 mm. The largest living amphibian is the 1.8 m "Chinese giant salamander"



A reptile is a cold-blooded vertebrate of the class Reptilia, comprising the turtles, snakes, lizards, crocodilians, amphisbaenians, tuatara, and various extinct members including the dinosaurs. Unlike mammals, birds, and certain extinct reptiles, living reptiles today have scales or scutes.

A reptile is any amniote (four-limbed animals with backbones or spinal columns that can lay eggs on land) that is neither a mammal nor a bird.

Most reptiles have a three-chambered heart consisting of two atria, one variably partitioned ventricle, and two aortas that lead to the systemic circulation with some exceptions.

All reptiles breathe using lungs. Most reptiles lack a secondary palate, meaning that they must hold their breath while swallowing. Reptilian skin is covered in a horny epidermis, making it watertight and enabling reptiles to live on dry land, in contrast to amphibians. Most reptiles are insectivorous or carnivorous and have rather simple and comparatively short digestive tracts, meat being fairly simple to break down and digest.

Saltwater Crocodile
Amoung still alive reptiles a tiny gecko, Sphaerodactylus ariasae is the smallest reptile which can grow up to 17 mm and the largest reptile is saltwater crocodile, Crocodylus porosus, which may reach 6 m in length and weigh over 1,000 kg.


Mammals are warm-blooded, usually hairy, vertebrates that give birth to live young ones and have three middle-ear bones.Most mammals also possess sweat glands and specialized teeth. Modern mammals evolved from reptiles. The early mammals laid eggs.

The class is divided into two subclasses:
1. The Prototheria ( which lays eggs )
2. The Theria (live-bearing mammals without using a shelled egg)

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Bumblebee Bat
Blue Whale
Smallest mammal is bumblebee bat in size from the 30–40 mm and the largest mammal is blue whale growng upto 33-meter.


Birds are warm-blooded vertebrate of the class Aves which are feathered, winged, bipedal, warm-blooded, egg-laying, vertebrate animals.

Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton.

All living species of birds have wings. Birds diets are varied and often include nectar, fruit, plants, seeds, carrion, and various small animals, including other birds.
Bee Hummingbird
Amoung still alive birds Bee Hummingbird is the smallest bird which can be 5 cm and the largest bird is Ostrich, which may be 2.75 m.


Fish are various cold-blooded, aquatic vertebrates, having gills, commonly fins, and typically an elongated body covered with scales. Most fish exchange gases using gills on either side of the pharynx.

Gills consist of threadlike structures called filaments. Each filament contains a capillary network that provides a large surface area for exchanging oxygen and carbon dioxide. Fish have a closed-loop circulatory system.

The heart pumps the blood in a single loop throughout the body. In most fish, the heart consists of four parts, including two chambers and an entrance and exit. Jaws allow fish to eat a wide variety of food, including plants and other organisms.

Fish ingest food through the mouth and break it down in the esophagus. In the stomach, food is further digested. Fish typically have quite small brains relative to body size compared with other vertebrates. Most fish possess highly developed sense organs.

Many types of aquatic animals commonly referred to as "fish" are not fish in the sense given above; examples include shellfish, cuttlefish, starfish, crayfish and jellyfish.
Stout Infantfish
Whale Shark
Fish range in size from the huge 16-metre whale shark to the tiny 8-millimetre stout infantfish.



Animal homes
Camels and their types
Animal Classification
Animal Feeding Behaviour
Interesting facts about Camels
Interesting facts about animals
Interesting facts about Rainforest animals
Facts about bats and their types
Facts about deer and their types
Facts about zebra and their types

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