Mollusks

Mollusks

Clam:Body Form & Skeleton-exoskeleton -body plan -foot-muscular region on bottom used for locomotion-contains-mouth, tongue, and teeth-visceral mass-area that surrounds organs, located right underneath shell- shell-created by glands in mantle-two shells, held together by two powerful musclesClam:Digestion-filter feeders-cilia and muscles and mucus on the gills trap food and particles-water enters clams through incurrent siphon -gastrointestinal tractClams:Respiration, Circulation, Excretion-respiration *breathe using gills inside mantle cavityCirculation-open circulatory system-blood is pumped by a simple heart that moves oxygen through the body -leaves and enters heart through different sinuses -large sac-like spaces Clam:Nervous System-simple nervous system-several nerve cords-simple sense organs

Gastropoda-pond snails and land slugs-either shell-less or have a single-spiral shaped shell -move using ventral footCephalopoda-octopus and squids-most active mollusks-soft bodied no shell or hard internal shell-head attached to single foot that divides into tentaclesBivalvia-clams, oysters, mussles, and scallops-have two shells-main focus for this phylum

Clam:Repoduction-reproduce sexually-external reproduction-clams release a large ammount of eggs and sperm into the water-eggs are fertilized and develop into free- swimming larvae-trochophore

land slug(gastropoda)

pond snail(gastropoda)

octopus(cephalopoda)

squid(cephalopoda)

diagram of a mollusk

clams, oysters, mussels, and scallops(bivalvia)

Variety-three classes *gastropoda *cephalopoda *bivalvia-

bivalvia diagram