Calvadosia cruxmelitensis is a stalked jellyfish (class Staurozoa, family Calvadosiidae) found in temperate coastal waters of the northeastern Atlantic and Mediterranean Sea, attaching to seagrass blades, algae, or other substrates using an adhesive pedal disc. Its vase-shaped body bears eight tentacle clusters and it feeds on small crustaceans and invertebrates. Stauromedusae are unique cnidarians in that they are sessile rather than free-swimming, and a genome assembly was produced for C. Stauromedusae are valuable for reconstructing the ancestral body plan of Medusozoa.