Box jellyfish box jellyfish's nervous system is more developed than that of many other jellyfish. They possess a nerve ring around the base of the bell that coordinates their pulsing movements, a feature found elsewhere only in the crown jellyfish. Whereas some other jellyfish have simple pigment-cup ocelli, box jellyfish are unique in the possession of true eyes, complete with retinas, corneas and lenses. Their eyes are set in clusters called rhopalia, located in pockets halfway up the outer, flat surfaces of the bell. Each contains two rhopalial ocelli with lenses, one directed upwards and the other downwards and inwards towards the
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