Scyphozoa

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The medusa phase dominates in most of the 200 species of scyphozoans, the cnidarians most frequently referred to as jellyfish. Scyphozoan medusae are larger and have a more complicated structure than the short-lived medusae of the hydrozoans. Scyphozoan medusae live several months or more, reproducing sexually to form small, inconspicuous polyps. Polyps reproduce asexually to form a medusa—saucer-like structures bud off the polyp and swim away as new medusae.

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