Jellyfish possess specialized structures called nematocysts, which are responsible for their ability to sting. When a jellyfish comes into contact with a potential prey item or a threat, it uses these nematocysts to inject venom.
It's important to note that the severity of a jellyfish sting and the resulting symptoms can vary depending on the species of jellyfish and the individual's reaction to the venom. Some jellyfish stings may cause only mild discomfort, while others can be more painful and potentially dangerous. If stung by a jellyfish, it is advisable to seek appropriate medical attention and follow recommended first aid measures for jellyfish stings.