Kingdom Animalia

Phylum Porifera The sponges. Porous body wall-allows food and water to enter. Adults are sessile(attached to ocean floor). Asymmetrical - no definite shape.

Phylum Cnidaria Formerly the coelenterates. Body wall made up of two layers-ectoderm and endoderm. Digestive system incomplete-one opening. Symmetry -radial

Phylum Platyhelminthes Flat bodies with three layers-ectoderm, mesoderm, and endoderm. Each layer forms specific organs and systems. Digestive system in free living species is incomplete-one opening.

Phylum Platyhelminthes continued. In the case of the parasitic flatworm, there is no digestive system as nutrients are simply absorbed directly from the host. Symmetry - bilateral with a definite head and tail system.

Phylum Nematoda The roundworms. Long, smooth and unsegmented body. Cylindrical with tapered ends. Three tissue layers-ecto-, meso-, and endoderm.

Phylum Nematoda continued Complete digestive system-two openings (mouth and anus). Symmetry -bilateral with an anterior and a posterior end.

Phylum Mollusca Includes the clams, snails, oysters and octopus. Soft, unsegmented body with a muscular foot. Scraper-like tongue called the radula.

Phylum Mollusca continued Mantle present. This is a fold of skin that surrounds the organs and produces secretions that help form the shell. Symmetry - bilateral

Phylum Annelida The segmented worms. Includes the earthworm, leech and sandworm. Body is segmented inside and out-allows for faster movement.

Phylum Annelida continued Complete digestive system -tube within a tube set up. Symmetry is bilateral. Anterior and posterior ends. Ventral and dorsal surfaces.

Phylum Arthropoda The arthropods include the insects, spiders and crustaceans. Segmented body with jointed appendages. Body divided into a head, abdomen and thorax.

Phylum Arthropoda Continued Exoskeleton made of chitin. Serves to prevent water loss and protects soft body. This has allowed the arthropods to be successful on land. Symmetry is bilateral.

Phylum Echinodermata The echinoderms include the sea urchins and sea stars. Internal limy skeleton, and a spiny outer surface provide support and protection.

Phylum Echinodermata continued A series of water-filled tubes (water vascular system) run through their bodies and allows them to create jets of water for movement. Symmetry is radial.

Phylum Chordata The chordates include the fish, amphibians, reptiles, birds and mammals. Symmetry is bilateral. Dorsal nerve cord. Flexible supporting rod or notochord.

Phylum Chordata continued In the vertebrates, cartilage or bone replaces the notochord to form a supporting backbone.