A Medusa is a marine creature better known by what other name?

A medusa is a marine creature better known as a jellyfish. The word “medusa” describes the free-swimming, umbrella-shaped body form found in many cnidarians, including true jellyfish, box jellyfish, and some hydrozoans.

Jellyfish belong to the phylum Cnidaria, alongside corals, sea anemones, and hydras. Their tentacles contain specialized stinging cells called cnidocytes, which help capture plankton and defend against predators. Despite their name, jellyfish are not fish: they are soft-bodied invertebrates with no backbone.

Many jellyfish have a two-stage life cycle. They begin as tiny, attached polyps and later develop into swimming medusae. The medusa is commonly the sexual stage, releasing eggs or sperm into the water. “Sea jelly” is sometimes preferred because jellyfish are not a single formal biological group.