1. Invertebrates

2. Definition Sub-Kingdom of Animals Animals that do not have a backbone at anytime during their development There are 8 major phyla of invertebrates

3. Porifera Sponges – “Pore Bearer” Characteristics: *Two cell layers with one body opening * Most are asymmetrical * Sessile (Do not move-Stuck in one place) * Filter Feeders

4. Cnidarians Characteristics * Two cell layers with one body opening * Most radial symmetry * Have stinging cells (nematocysts) * Two life stages, polyp (baby) and medusa (adult) Examples * Jellyfish, corals, sea anemones, hydras

6. Platyhelminthes Flatworms Characteristics * Bilateral symmetry * Flattened bodies * One body opening * Slightly developed nervous and sensory systems Examples: * Tapeworms, flukes, planarians

7. Tapeworms in Body

8. Nematoda Roundworms Characteristics * Tubelike digestive system with 2 body openings * Many parasitic— hurt other organisms * Sensory eyespots

9. Heartworm—A Parasitic Roundworm

10. Mollusca Mollusks Characteristics * Bilateral symmetry * Body cavity for organs * 2 Body openings with completed digestive tract * Mantle (surrounds internal organs; secretes shell in most mollusks) * Muscular foot for movement

11. Mollusca Continued * Live in water Examples: * Gastropods (1 Shell) Snails * Bivalves (2 Shells) Clams * Cephalopods (head- footed) Octopi, Squid

12. Annelida Segmented Worms Characterisitcs: * Bilateral Symmetry * Coelom and two body openings Coelom Segmentation— provides for great flexibility Segmentation— provides for great flexibility Have Setae (hairs) Have Setae (hairs)Examples: * Leeches, earthworms, bristleworms

14. Arthropods Characteristics: * Bilateral Symmetry * Exoskeletons—tough outer coverings that protects and provides support *Jointed appendages * Some have fused segments Examples: * Insects, spiders, crabs, centipedes

16. Echinodermata Characteristics: * Radial Symmetry (Larvae have radial) * Endoskeleton—internal skeleton for support * Rough exterior that looks like a “spiny skin” * Water vascular system for movement—changes pressure which creates a suction on “feet” Examples: * Sea Stars, Starfish, Sand Dollars

17. Invertebrate Chordate Characteristics: * Chordates—Have a notochord, dorsal nerve cord, gill slits, muscle blocks during all or part of life cycle * Bilateral Symmetry * Most advanced of invertebrates Examples: * Tunicates (Sea squirts), lancets