Jellyfish Jellyfish Jellyfish or sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles, although a few are not mobile, being anchored to the seabed by stalks. The bell can pulsate to provide propulsion and highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle; the medusa is normally the sexual phase, the planula larva can
Blue jellyfish Blue jellyfish Cyanea lamarckii, also known as the blue jellyfish or bluefire jellyfish, is a species of jellyfish in the family Cyaneidae. Populations in the western Pacific around Japan are sometimes distinguished as "Cyanea nozakii" or "Cyanea capillata nozakii". This species is found in the pelagic zone off the west coast of Scotland, the North Sea and the Irish Sea, sometimes with the more common Lion's Mane Jellyfish, ("Cyanea capillata"). "C. lamarckii" has a blue or yellow tone and grows to approximately 10 to 20 cm across, but specimens can grow to 30 cm. In Scandinavian seas this species rarely