Subphylum Vertebrata

Subphylum vertebrata contains five classes and this are as follows-

• Class Pisces
• class Amphibia
• Class Reptilia
• Class Aves
• Class Mammalia

1) Class Pisces-

1. These are fish.
2. They are exclusively aquatic animals.
3. Their skin is covered with scales.
4. They obtain oxygen dissolved in water by using gills.
5. The body is streamlined, and a muscular tail is used for movement.
6. They are cold-blooded and their hearts have only two chambers, unlike the four that humans have.
7. They lay eggs.

Fish

2) Class Amphibia-

1. These animals differ from the fish in the lack of scales, in having mucus glands in the skin, and a three chambered heart.
2. Respiration is through either by gills or lungs.
3. They lay eggs.
4. These animals are found both in water and on land.

Examples-  Frogs, Toads and salamanders.

Frog

3) Class Reptilia-

1. These animals are cold-blooded, have scales and breathe through lungs.
2. While most of them have a three-chambered heart, crocodiles have four heart chambers
3. They lay eggs with tough coverings and do not need to lay their eggs in water, unlike amphibians.

Examples- Snakes, Turtles, Lizards, Crocodiles.

Snake

4) Class Aves-

1. These are warm-blooded animals and have a four chambered heart.
2. They lay eggs.
3. There is an outside covering of feathers and two forelimbs are modified for flight.
4. They breath through lungs.
5. All birds fall in this category.

Bird

5) Class Mammalia-

1. Mammals are warm-blooded animals with four-chambered hearts.
2. They have-mammary glands for the production of milk to nourish their young.
3. Their skin has hairs as well as sweat and oil glands.
4. Most mammals to us produce live young ones.
5. However, a few of them, like the platypus and the echidna lay eggs and some like kangaroos give birth to very poorly developed young ones.

Cat