It resembles the Medusa of Greek mythology. In the legend, Medusa s face was surrounded by a ring of snakes, similar to the tentacles of a jelly. Instead of biting snakes, however, each tentacle of a jelly is filled with stinging cells called cnidocytes. These specialized cells are used for defense and feeding and contain small stinging structures full of toxins called nematocysts. Some nematocysts carry a sting so strong that they are deadly to most animals, including humans.
Most jellies have four stomachs that receive their food through a central mouth.
Prey is stung by the tentacles around and on the bell of the jelly and then transferred to the four oral arms that surround the mouth opening. From there the food travels up into the stomachs, where it is digested. Any undigested food is then passed back through the mouth opening and out into the water. To move, the jelly contracts a sheet of muscles near the rim of the bell. Even though it can move up and down in the water column, it is no match for the ocean currents.