1. WARM UP 1.List seven characteristics of roundworms.

2. Mollusks Notes Phylum Mollusca

3. General Characteristics Live in a variety of habitats Extreme diversity – About 100,000 species – Six classes

4. Structure Mantle protects the soft body and secretes the shell Gills for gas exchange Visceral mass contains the organs Muscular foot used for movement Open circulatory system – Structures are bathed in blood

5. Class Gastropoda “Belly foot” The largest class of mollusks – Snails, slugs, etc. Use a tongue-like radula to scrape and tear food

6. Class Bivalvia Pelecypoda = “hatchet foot” – Use foot for burrowing Clams, oysters, scallops Two part hinged shell – Muscle to open and close Filter feeders – Use gills – No distinct head or radula

7. Class Cephalopoda – “Head foot” – Squid, octopus, nautilus, cuttlefish – Adapted for active predation Well-developed head, eyes, and nervous system Foot is modified into tentacles Can move quickly by jet propulsion – High oxygen demand – Closed circulatory system Radula and jaws

8. WRAP UP Place each of the pictures into the correct Class of Phylum Mollusca. Choices are Bivalvia, Scaphopoda, Polyplacophora, Monoplacophora, Gastropoda, Cephalopoda