1. Sponges and Cnidarians Sponges- Asymmetrical Specialized cells, but no tissues, organs, or organ systems Cnidarians Radial symmetry Single opening surrounded by tentacles Have simple tissues Nematocysts (stinging cells)

2. How nematocysts work for defense and catching food

3. Flatworms (platyhelminthes) Soft, flattened bodies Only a few cells thick Nerve, muscle, digestive tissues Only 1 opening on digestive system Most (but not all) are parasites Must live in a moist environment – inside a host marine environment

4. Roundworms (Nematodes) Nerve, muscle, digestive tissues simple brain Must live in moist environments Protective outer layer – the cuticle Two openings on digestive system Some are parasites, some eat dead things or feces

5. Mollusks Soft bodies, some have shells Two-opening digestive system Specialized cells, tissues, and organs such as stomach, heart Open circulatory system Simple brain Live in moist environments

6. Annelids – segmented worms Soft bodies with repeating segments Thin cuticle Two-opening digestive system Closed circulatory system Simple brains See organs on diagram Some organ systems

7. Arthropods More arthropods than all other animals combined Insects, spiders, crabs, shrimp Hard outer covering called an exoskeleton Jointed appendages (bendable arms and legs) 3 major classes: Insects Arachnids Crustaceans

8. Insects Largest order of Arthropods Jointed legs (They have knees…) 6 legs, in 3 pairs 3 body segments 2 antennae Compound eyes Tasty when sauteed in garlic butter

9. Insects Largest order of Arthropods Jointed legs (They have knees…) 6 legs, in 3 pairs 3 body segments 2 antennae Compound eyes Tasty when sauteed in garlic butter

10. Echinoderms More closely related to vertebrates than other invertebrates Complete, 2-opening digestive system Only live in oceans Water-vascular system with tube feet Some can survive brief periods of time out of water The body is supportd by hard plates stuck in the skin

11. Homework! Phylumspecialized tissueorgansorgan system cells Porifera Cnidarians Flatworms Nematodes Mollusks Annelids Arthropods