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the larva of most coelenterates of the class Scyphozoa. The larvae are formed asexually by means of transverse fission of the polyploid generation—the scyphistoma. The edge of the umbrella forms eight double lobes. Tentacles and oral lobes are absent. The digestive system is rudimentary: in addition to the stomach, there are only two rudiments of radial canals. The youngest ephyrae are transparent and reach several mm in diameter. Transformation into an adult jellyfish is accompanied by rapid growth. The edge of the umbrella becomes more regular, and a complex gastrovascular system, lateral tentacles, and the rudiments of sex glands develop.