1. Mollusks Phylum: Mollusca Sea Snail Cockle Shell Green Mussel Octopus

2. Mollusk Characteristics Soft-bodied invertebrate covered with protective mantle that MAY or MAY NOT form a hard, calcium carbonate shell Soft-bodied invertebrate covered with protective mantle that MAY or MAY NOT form a hard, calcium carbonate shell Have a muscular foot for movement which is modified into tentacles for squid & octopus Have a muscular foot for movement which is modified into tentacles for squid & octopus Complete, one-way digestive tract with a mouth & anus Complete, one-way digestive tract with a mouth & anus Have a fully-lined coelom Have a fully-lined coelom Cephalization - have a distinct head with sense organs & brain Cephalization - have a distinct head with sense organs & brain Have a scraping, mouth-like structure called the radula Have a scraping, mouth-like structure called the radula Go through free-swimming larval stage called trochophore Go through free-swimming larval stage called trochophore

3. Mollusk Characteristics Body organs called visceral mass lie below mantle Body organs called visceral mass lie below mantle Have circulatory, respiratory, digestive, excretory, nervous, & reproductive systems Have circulatory, respiratory, digestive, excretory, nervous, & reproductive systems Bilaterally symmetrical Bilaterally symmetrical Most have separate sexes that cross-fertilize eggs Most have separate sexes that cross-fertilize eggs Gills are used for gas exchange Gills are used for gas exchange Includes chitons, snails, slugs, clams, and oysters Includes chitons, snails, slugs, clams, and oysters

5. Class: Gastropoda Single Shell (uni-valve) Snails, conch, abalones, slugs Snails, conch, abalones, slugs Soft, inside body Soft, inside body Radula- mouth that scrapes food Radula- mouth that scrapes food Breathes through skin Breathes through skin Stomach footed Stomach footed Sea Butterfly Oyster Drill

6. Snail Slug

7. Class: Cephalopods No shells Head footed mollusks- ten tentacles Head footed mollusks- ten tentacles All salt water All salt water Squid, octopus, cuttlefish, nautilus Squid, octopus, cuttlefish, nautilus Some contain internal shell Some contain internal shell

8. Chambered Nautilus Octopus Squid

9. Class: Pelycypoda Hatchet footed- used for movement and to bury in the sand Hatchet footed- used for movement and to bury in the sand All have two shells (bi-valve) All have two shells (bi-valve) Produce three layers to shells Produce three layers to shells 1. Pearly layer- inside layer 2. Prismatic layer- middle layer 3. Horny layer- outside layer Made of calcium carbonate: thin membrane called mantle produces shell Made of calcium carbonate: thin membrane called mantle produces shell Mucus feeder- takes in water and filters microorganisms for food Mucus feeder- takes in water and filters microorganisms for food Breathes by gills Breathes by gills Clams, oysters, scallops, zebra mussels Clams, oysters, scallops, zebra mussels