PHYLUM ECHINODERMATA

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PHYLUM ECHINODERMATA

• Radial and bilateral stage, but NO HEAD!
• 2 openings
• Endoskeleton - internal skeleton
• Spiny skin
• Water vascular system
• Feeds by prying open shells and sending stomach
  outside of body for digestion
• Some are detritus or filter feeders
• Respiration - diffusion
• Moves with use of tube feet
• Regeneration abilities
• Open water fertilization

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Deuterostomes

• -form anus first (mouth second)
• -radial cleavage
• -allows for more complex body structure

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ECHINODERM CLASSIFICATION

• 5 Classes (Know the examples)
• CLASS ASTEROIDEA-starfish
• CLASS ECHINOIDEA- sand dollar, sea urchin
• CLASS HOLOTHUROIDEA- sea cucumber
• CLASS CRINOIDEA- feather stars
• CLASS OPHIUROIDEA- brittle stars

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Echinoderms
Sand dollar
Sea cucumber
Starfish
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Brittle stars

• Feather stars

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Why are they important?

• Control population of other animals
• Control algae population
• Problem Can sometimes eat out of control