Mollusks

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Mollusks
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Mollusk Features

• True coelum
• Bilateral symmetry
• 3 part body plan
• A) Visceral Mass central section contains
  organs
• B) Mantle Tissue that secretes shell
• C) Muscular Foot

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Mollusk Features

• Have organ systems
• Usually separate male/female sexes
• Shells made of protein and calcium
• Radula tongue-like organ to scrape food

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Gastropods slugs, snails

• Stomach Foot
• Mostly marine
• Most single shell
• Foot secretes slime to move
• Feeding
• Herbivores scrape food with radula
• Predators poisonous dart to swallow prey whole

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Bivalves clams

• Most marine
• Shell secreted by mantle
• No distinct head region or radula
• Filter feeders
• Sperm egg released into water
• Larvae free swimming

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Cephalopods squid, octopus

• Head foot
• Large head attached to tentacles
• Complex nervous system brain
• Expel water through siphon to move
• Jet propulsion
• Active predators