Last Christmas, when The (then) Four-Year-Old was surveying Panama City Beach for a likely spot to construct a landing pad for Santa and his reindeer, she came across a jellyfish.
Naturally I panicked. “Don’t step in that! It might sting you!”
The (then) Four-Year-Old, practically: “But it’s dead.”
Mommyo: “Doesn’t matter. It can sting anyway.”
The (then) Four-Year-Old was dubious, but fortunately decided that if there was even a chance that Santa or his reindeer might be stung by a jellyfish, she needed a different spot.
She didn’t say anything else about the jellyfish at the time, but when we returned to the condo after building Santa’s parking spot, she immediately consulted a wiser power.
The (then) Four-Year-Old: “Grandma, can jellyfish sting you after they’re dead?”
Grandma: “Of course.”
The (then) Four-Year-Old: “For how long?”
Grandma, rapidly calculating how many days were left in The (then) Four-Year-Old’s visit: “Two weeks.”
How long can jellyfish really sting after they’re dead?
The real answer, it seems, is not “Two weeks”, but however long it takes for the stingers to run out of sting.
Jellyfish are not active stingers. Whether the animal is alive or dead means nothing to its nematocysts (the little cells in the tentacles in charge of stinging you). Each tentacle can contain hundreds or even thousands of these stinging cells. When a tentacle comes in contact with an object, pressure forces stinging threads inside the nematocysts to uncoil rapidly, acting as mini-harpoons to inject the unwary with paralyzing toxins.
Most species of jellyfish only release enough toxin to paralyze or kill small fish and crustaceans, but some jellyfish can be harmful to humans, depending on the strength of the toxin, your sensitivity to it, and the thickness of your skin.
The (then) Four-Year-Old: “That’s real thick in your case, Mommyo.”
The real question you should ask when you pass a jellyfish on the beach
That’s why the real question when you find a jellyfish on the beach isn’t “Is that thing dead?” but “Have the nematocysts released their toxins yet?” (See how much smarter you sound?) Until they do, that jellyfish is potentially bad news.
Of course, there’s no way for the average person to tell such a thing just by looking at (or using a stick to poke at) a jellyfish. So as Grandma says, the best thing to do is to steer clear of all jellyfish (and jellyfish bits) you may encounter on the beach entirely. Give those suckers time to be snapped up by sea turtles (who are unaffected by their sting) or at the very least washed back out to sea.
- The 6 Most Amazing Jellyfish in the Sea (Jellyfish Facts)
- Death does not deter jellyfish sting (New York Times)
- Jellyfish (Sea Science)
- Jellyfish in Florida (Beachhunter.net): Has lots of photos of the different kinds of jellyfish you’ll encounter on the beaches of the Gulf of Mexico
- Deadly jellyfish weapons unraveled (sciencedaily.com)