Jellyfish eat their prey by first paralyzing them by stinging them, and then drawing the prey in through the mouth, which is a hole in the middle of the jellyfish's body, reports National Geographic. When the jellyfish has eaten and digested the prey, the waste is released through this same hole, or "mouth."
Jellyfish eat a variety of foods including small ocean plants called phytoplankton, shrimp, fish, fish eggs, crabs, copepods, fish larvae and planktonic eggs. On occasion, a jellyfish may also eat another jellyfish, though this is not an everyday or usual occurrence, according to the Tennessee Aquarium. Jellyfish are most often eaten by sea turtles, who loves the taste of jellyfish.
Jellyfish can live in deep water, shallow water along the coast and both warm and cold water. They will live anywhere from a few days to a single year depending on the species and the gender of the jellyfish. Jellyfish are a necessary species in the ocean not only because of their role in the food chain, but also because they help other animals. Jellyfish are often seen protecting younger fish from predators when the fish cannot find a place to hide because the predators are scared of the jellyfish's stinging abilities.