What triggers jellyfish to sting???


Why is it that a jellyfish tentacle releases its venom or spikes or whatever when it comes into contact with human skin, but not, for example, when it comes in contact with sand or a rock? You can touch the surface a jellyfish has been sitting on, no problem, but as soon as you get direct contact it leaves pain behind.. why is that? What is it about skin contact that triggers the jellyfish to release their sting, if not the pressure of contact? Can it “sense” what is alive and what isn’t when it stings? On a cellular level, how does that work?!

In: 3

This was a mysterious thing for quite a long time, in fact there was a question about why jellyfish weren’t just stinging themselves. A team out of Harvard finally looked into it and discovered that there is the touch sensitive element of the stinging cells, but *also* chemical sensors as well. In short the “trigger” to fire the cell needs more than one source of stimulation, if it’s just rubbing against some wood or sand then nothing wil happen. If it touches something made of what animals are made of though, boom.

In a very basic sense it’s touching and tasting, and when the two sensations overlap in the right way the cell fires. That’s also how clownfish mucous can protect the fish from stinging cells, because even though it doesn’t stop the cells from sensing pressure, it “tastes” wrong. The fish uses the stinging cell’s programming to prevent the jellyfish or anemone from stinging its own body against it.