Cnidarians

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Cnidarians

• Coral
• Sea anemones
• Jellyfish
• Distinguishing characteristic stinging tentacles

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Corals
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Sea Anemones
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Jellyfish
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Body Forms

• Polyp (coral, anemones)
• Cylinder, mouth at top
• Sessile
• Medusa (jellyfish)
• Umbrella-shaped
• Free-swimming

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Body Structure

• 2 cell layers ectoderm, endoderm
• Mesoglea middle layer (gel-like)
• Gastrovascular cavity

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Body Symmetry

• Radial
• Capture food from all directions

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Body Systems

• Skeletal
• None hydrostatic pressure
• Nervous nerve net, no brain
• Muscular cells in bands
• Jellyfish propulsion

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Nerve Net
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Stinging Cells (Cnidocytes)
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Feeding

• Tentacles sting and grasp prey
• Into GV cavity via mouth
• Enzyme secreted
• Digestion completed by cells

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Reproduction

• Sexual and asexual
• Budding
• Regeneration

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Colonies

• Buds dont break off animals becomes branched
  colony

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Portuguese Man-of War

• Colony medusae and polyps

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Organ Pipe Coral
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Deerhorn Coral
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Brownstem Coral
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Lace Coral
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Northern Star Coral
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Northern Star Coral
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Coral Lab