Jellyfish stings come from stinging cells that fire tiny harpoons when something brushes past.

The longer version

Each stinging cell holds a coiled thread held under pressure inside a capsule, with a trigger hair projecting outward. Touch bends that hair, the capsule fires, and the thread turns inside out in a fraction of a second, piercing whatever brushed past and releasing proteins.

The mechanism is pure stored tension, so it operates even after death or separation. Sizes differ widely: fine threads snag drifting larvae and small crustaceans, while heavier versions target larger prey. Most produce effects in people that are mild and short-lived, though a handful of species pack venom strong enough to matter greatly.

Where this entry sits

Oceans and Sea Life looks at the salt water that covers most of the planet, from crashing waves and tides to the darkest deep-sea trenches. Expect notes on coral, fish, whales, sharks, jellyfish, shells, and the strange creatures that live far below the surface. The full list sits on the Oceans and Sea Life page, where every entry is listed in order.