What Do Jellyfish Eat
What do jellyfish eat? We know a little bit about the type of food that the jellies prefer to “graze” on, and the exact food types vary from place to place and ocean to ocean.
Jellyfish are carnivores, meaning they are meat-eaters. But, specifically what do jellyfish eat? The smaller sized jellies eat jellies smaller than themselves, smaller fish and most often zooplankton.
That tells us what small jellyfish eat, but what about the giant varieties of the species? What do jellyfish eat if they're big enough to be choosier about their menu? Larger jellies usually eat sea animals and larger crustaceans, sometimes shrimp.
The majority of jellyfish drift on ocean currents and feed on prey, living or dead, that is gathered by their tentacles, and stung by their nematocysts. What do jellyfish eat the most, in the oceans of the world? They will eat invertebrates that are caught by their tentacles, as well as eggs and some small fish. Their digestive system is not complete, which results in their “mouth” being used both for intake of food and for expulsion of waste.
Jellies have stinging nematocysts on their tentacles, and when a prey animal touches a tentacle, hundreds – to thousands – of nematocysts fire at the prey, and latch onto it to bring it closer to the jellyfish's “mouth”, for the beginning of digestion.
Jellyfish eat through an opening, a “mouth” of sorts, that takes the prey straight into their stomach after it is paralyzed by the tentacles' venom.
The phylum that jellyfish belong to is the Coelenterada. This word means, literally, “hollow intestine”. As they are intent on eating their zooplankton and crustaceans, there are larger animals looking at the jellyfish as prey. Sea turtles, sunfish and spade fish all make jellyfish part of their diet.
So, what do jellyfish eat when they drift through the ocean currents with their tentacles waiting to catch dinner? In addition to the foods we've mentioned, jellies also will eat sea animal eggs, little shrimp, young sea animals and even other jellyfish.
Freshwater jellies generally have less variety in their diet than their marine cousins, simply because there aren't that many disparate animals in fresh waters that they can catch. They feed often on zooplankton, just like ocean-dwellers do, but they don't have the variety in their diet that salt-water jellies do.