hydrocoral

invertebrate

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June 29, 2026

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Hydrocorals are marine invertebrates belonging to the class Hydrozoa. They are characterized by a well-developed calcareous skeleton, distinguishing them from many other hydrozoans that secrete chitinous external skeletons. These skeletons are composed of calcium carbonate and are internal, meaning they are penetrated by channels of living tissue.12

Hydrocorals include orders like Milleporina (fire coral) and Stylasterina, which form encrusting or branching skeletons similar to those of anthozoan corals. These animals are colonial, with different types of polyps within the colony serving specific functions, such as feeding, reproduction, and protection. Fossil representatives of similar organisms date back to the Jurassic Period.13

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cnidarian
Size range and diversity of structure
…groups such as hydroids and hydrocorals. 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…
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…groups such as hydroids and hydrocorals. 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…
Read More