Phylum Mollusca Yum Yum

Defining Characteristics Mantle- tissue that secretes calcium carbonate shell Foot- locomotion Soft-bodied (not including shell)

Classes Bivalvia- clams/ oysters Gastropoda- snails/ slugs Cephalopoda- squid/ octopus

Bivalve Anatomy

Bivalves Sessile- clams motile- oysters Filter feeders Gills for gas exchange Excrete out anus Separate sexes- broadcast gametes Brain and major nerve cord (no cephalization) Siphon- tube in- O2 rich water and food -tube out-CO2 rich water

Digging Clam

Swimming Scallop

Gastropod Anatomy

Gastropods Mantle does not produce shell Organ systems similar to bivalves Crawl on stomach using muscular undulations Radula- tongue-like structure used for feeding hermaphroditic Cephalization Diffusion through gills/ wet membrane

Zombie Snail

Cephalopod Anatomy

Houdini the Octopus

Cephalopods Cephalo- head Pod-foot Mantle produces bony plate to protect brain Organ systems similar to bivalves Large head Well-developed nervous system Siphon (funnel)- expels water…Quick moving Closed circulatory system Release ink to confuse predators Eye- similar to mammals (retina, lens, cornea, iris) Radula- for feeding

Your Activity You are to circulate through each of the stations. Make observations on each of the type of shells and organisms in each Class. Diagrams (in pencil) Notes on patterns of growth