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.