Annelids

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Annelids Mollusks
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Mollusks

• Snails
• Slugs
• Clams
• Oysters
• Squids
• Octopuses

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Mollusks

• Most live in oceans
• Some in freshwater
• Some on land
• Complex ganglia
• Some have large brains

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Mollusk Bodies

• Muscular foot snails and slugs leave a mucus
  trail
• Visceral mass internal organs like the gills
  gut
• Mantle layer that protects the visceral mass or
  secretes a shell for protection

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Circulatory System

• Transports materials through the body in the
  blood
• Open circulatory system blood is not totally
  contained in vessels
• Closed circulatory system blood is totally
  contained in blood vessels that form a closed
  loop to and from the heart

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Gastropods

• Slugs, snails, abalones, whelks, conches, sea
  slugs
• Radula a tongue-like organ covered with curved
  teeth used to scrape food
• Most have a single shell (univalve)
• Open circulatory system

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• 2 shells
• Use gills to filter feed from the water
• Often attach to one place
• Use muscles to close their shells
• Open circulatory system

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Cephalopods

• Most advanced nervous systems and the smartest
  invertebrates
• Use tentacles to grab their food
• Closed circulatory system

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Annelids

• Segmented worms
• Segment a repeating body part that you can see
• Bilateral symmetry
• Closed circulatory system
• Nervous system with a brain
• The brain is attached to ganglion in each segment
• Live in salt or fresh water and on land
• 3 groups earthworms, marine worms, leeches

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Earthworms

• 100-175 segments
• Eat plant animal matter from the soil
• Leave wastes called castings
• Castings help make the soil richer
• Use tiny bristles to move through the soil

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Marine Worms

• Beautiful
• Polychaetes (poly-keets) means many bristles
• Many colors
• Most live in oceans
• Some eat mollusks others eat by filter feeding
• Fireworm, Fanworm, Christmas Tree worm

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Leeches

• Parasites (suck blood)
• Scavengers (eat dead things)
• Predators of insects, slugs, snails
• Release a chemical to keep blood flowing
• Used in medicine to increase blood flow and
  reduce swelling and clotting