Jellyfish are poisonous. Be careful when you swim

You're swimming in the ocean when something brushes your leg. When the tingling sets in, you realize you've been stung by a jellyfish.How do these beautiful, gelatinous creatures pack such a painful punch? Jellyfish are soft because they are 95% water and are mostly made of a translucent gel-like substance called mesoglea. With such delicate bodies, they rely on thousands of venom-containing stinging cells called cnidocytes for protection and prey capture.