Moon Jellyfish have a wide variety of fish in their diet. They eat zooplankton, mollusks, crustaceans, copepods, nematodes and eggs of fish and shrimp. They catch their food by stinging them. Their tentacles have venom in them which paralyzes or can even kill their prey. Their predators are sea turtles and large birds. Although they don't have many predators sea turtles are a major threat. To the sea turtle the moon jellyfish is their lunch.