DefinitionJellyfish are sea creatures that have a nearly see-through (transparent) body with long finger-like structures called tentacles. Stinging cells inside the tentacles can hurt you if you come in contact with them. Some stings can cause serious harm.This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the National Poison Control Center at 1-800-222-1222.Poisonous IngredientJellyfish venomWhere FoundTypes of jellyfish include:Lion's mane (Cyanea capillata)Portuguese man-of-war (Physalia physalis)Sea nettle (Chrysaora quinquecirrha), one of the most common jellyfish found along the Atlantic and Gulf CoastsSea wasp (Chironex fleckeri, Chiropsalmus q