Echinoderms

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Echinoderms
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I. Deuterostomes

1. Radial clevage
2. Enterocoelous coelom formation
3. Determiant clevage
4. Blastopore becomes anus

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II. Echinoderm classes

• A. Asteroidea-starfish
• B. Ophiduroidea-brittlestars
• C. Echinoidea-sea urchins
• Holothuroidea-sea cucumbers
• Crinoidea-featherstars

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III. Water vascular system

• A. Structure
• B. Function

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IV. Digestive System

• A. oral vs aboral surface
• B. cardiac vs pyloric stomach
• C. hepatic ceca
• D. intestine and anus

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Starfish feeding on a mussel
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V. Reproductive system

• A. Different sexes
• B. Reproductive products released into open water
• C. Regeneration

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VI. Ray cross section

• 1. Coelom
• 2. Calcareous plate
• 3. Dermal branchiae
• 4. Hepatic ceca
• 5. Spine
• 6. Radial canal
• 7. Pedicellariae
• 8. Radial nerve
• 9. Tube foot
• 10.Sucker

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Pedicellariae