Animal Kingdom

Porifera

1. Porifera means organisms with holes.  This are non-motile animals attached to some solid support.
2. These lead to a canal system that helps in circulating water throughout the body to bring in food and oxygen.
3. Covered with a hard outside layer or skeleton the body design involves very minimal differentiation and division into tissues.
4. They are commonly called sponges and are mainly found in marine habitat.
5. They are commonly called sponges and are mainly found in marine habitats.
6. Examples- Euplectelea, Sycon, Spongilla.

Colenterata (Cnidaria)

1. These are animals living in water.
2. They show more body design differentiation.
3. There is a cavity in the body.
4. The body is made of two layers of cells one makes up cells on the outside of the body and the other makes the inner lining of the body.
5. Some of these species live in colonies (corals) while others have a solitary like- span (Hydra) jellyfish, hydra and sea anemones are common examples.

Platyhelminthes

1. The body of animals in this group is far more complexly designed than in the two other groups we have considered so far.
2. The body is bilaterally symmetrical, meaning that the left and the right halves of the body have the same design.
3. There are three layers of cells from which differentiated tissues can be made, which is why such animals are called triploblastic.
4. There is thus some degree of tussue formation. However, there is no true internal body cavity or coelom, in which well developed organs can be accommodated.
5. The body is flattened dorsiventrally, meaning from top to bottom, which is why these animals are called flatworms.
6. They are either free living or parasitic, some examples are free living animals like planarians or parasitic animals like liverflukes.

Liver fluckes

Nematoda

1. The nematode body is also bilaterally symmetrical and triploblastic, However the body is cylindrical rather than flattened.
2. There are tissues, but no real organs although a sort of body cavity or a pseudocoelom is present.
3. These are very familiar as parasitic worms causing diseases such as the worms causing in the intestines (roundworm or pinworm).
4. Examples- Ascaris, Wucheria

Ascaris

Annelida

1. Annelid animals are also bilaterally symmetrical and triploblastic, but in addition they have a true body cavity.
2. This allows true organs to be packaged in the body structure.
3. There is thus, extensive organ differentiation fashion, wtih the segments lined up one after the other from head to tail.
4. These animals are found in a variety of habitats fresh water, marine water as well as land. Earthworms and leeches, Nereis are familiar examples.

Arthropoda

1. This is probably the largest group of animals.
2. This animals are bilaterally symmetrical and segmented.
3. There is an open circulatory system, and so the blood does not flow in well defined blood vessels.
4. The coelomic cavity is blood-filled.
5. They have jonted legs.
6. The word "arthropod" means 'jointed legs'.
7. Some familiar examples are Prowns, Butterflies, Houseflies, Spiders, Scorpion and Crabs.

Scorpion

Mollusca

1. In the animals of this group, there is bilateral symmetry.
2. The coelomic cavity is reduced. There is little segmentation.
3. They have an open circulatory system and kidney- like organs for excretion.
4. There is a foot that is used for moving around. E.g  Snails 
5. Examples- Chiton, Octopus. Pila, Unio.

Pila

Echinodermata

1. In greek, derma means skin.
2. Thus these are spiny skinned organisms.
3. This are exclusively free-living marine animals.
4. They are triploblastic and have a coelomic cavity. 
5. They also have a peculiar water-driven tube system that they use for moving around.
6. They have hard calcium carbonate structures that they use as a skeleton. Examples are starfish and sea urchins.
7. Examples- Holothuria (sea cucumber) Echinus (sea urchin) Asterias (star fish) Antedon             (feather star).

Echinus