Massachusetts Zoos, Aquariums and Wildlife

Jellyfish are not fish at all. They are invertebrates, relatives of corals and sea anemones. A jelly has no head, no bones, no brain, no heart, no eyes, and no ears. But that doesn't keep them from eating and surviving. To capture prey for food, jellies have a net of tentacles that contain poisonous, stinging cells. When the tentacles brush against their prey, thousands of tiny stinging cells explode, launching barbed stingers and poison into the victim. OUCH!

Anywhere there is water—from icy polar seas to tropical Pacific shores—there are jellies. Scientists estimate there may be 2,000 species of jellyfish.