hydromedusa

cnidarian

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June 29, 2026

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A hydromedusa is a specific type of medusa, which is one of the two main body forms of cnidarians, an invertebrate animal phylum that also includes jellyfish. The medusa form is typically bell- or umbrella-shaped and is free-swimming. Hydromedusae are produced as buds from a hydroid, which is the polyp stage of a cnidarian. While many cnidarians alternate between polyp and medusa stages in their life cycle, hydromedusae are generally smaller and more delicate than other types of medusae, and in some species, the medusa stage may be absent. Cnidarians are characterized by radial symmetry and possess tissues but not complex organs.1234

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cnidarian
Size range and diversity of structure
Hydromedusae are smaller and more delicate than scyphomedusae or cubomedusae; they may be completely absent from the life cycle of some hydrozoan species. Some other species produce medusae, but the medusae never separate themselves from the polyps. Cubozoans have medusae commonly known as box jellyfish,…
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Hydromedusae are smaller and more delicate than scyphomedusae or cubomedusae; they may be completely absent from the life cycle of some hydrozoan species. Some other species produce medusae, but the medusae never separate themselves from the polyps. Cubozoans have medusae commonly known as box jellyfish,…
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