Cnidaria - Corals, Jellyfish, Stingers

Sea Fan

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A Lithographic Plate by Haeckel (1900) on Art Forms of Nature showing many species of Sea Anemone

Portuguese Man of War

All Cnidaria have specialised cells called Nematocysts ( like a poisonous harpoon) used for capturing prey. May be swimming medusae or sessile polyps. Have a single body cavity for respiration and digestion. Simple net like nervous system. Mostly carnivorous otherwise filter feeders.

Generally produce colonies acting like one single creature. Cnidaria have existed 580 million years ago. There are some 11,000 species identified and counting.

Have a complex life cycle and can reproduce sexually and asexually. Has a distinct larval stage which is planktonic.

Comprise of sea anemones, corals, jellyfish, hydras, sea whips, sea fan and sea pansies (mainly marine)

Clip 1: Learn How the Cnidarians First Evolved

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Clip 4: Learn How the JellyFish evolved