Why does water tingle? It turned out to be a "grenade" thrown by a jellyfish

Science and Technology Daily News (reporter Zhang Mengran) Snorkelers in some waters will feel the tingling sensation in the water, but they have not touched any jellyfish. According to a paper recently published in the British journal Communications Biology, scientists have found a new structure formed by thorn cells in the mucus of an inverted jellyfish, which is thrown out by the jellyfish like a mini grenade, which is the reason for the "tingling water" that has been plaguing people.

The inverted jellyfish are of the genus Fairy Jellyfish, and the mangrove forest is home to the genus Nymph Jellyfish, which stay upside down on the shallow seabed, with their folded mouths and wrists facing upwards. Snorkelers in the waters around Florida, the Caribbean and Micronesia have long reported that they feel stung by jellyfish without direct contact with any jellyfish, which means that the water can cause a tingling sensation. The researchers have suggested many possible sources of prickling sensation in the water, but the exact cause has been unknown.

This time, scientists at the National Academy of Sciences and the Center for Biological/Molecular Sciences and Engineering at the U.S. Naval Research Laboratory consulted the scientific literature on the genus Nymphsee since the early 20th century for clues related to this "tingling water." They learned that the mucus released by the genus Fairy Jellyfish contains very tiny clumps of cells, which are named cassiosome. Using a microscope, it was found that the outer membrane layer of these cassiosomes was arranged with thousands of jellyfish spine cells. These spiny cells are called stinging cells, which are sacs containing venom, which are generally found in specific cells of jellyfish tentacles.

The analysis showed that this structure not only helps jellyfish to prey, but also releases these mucus filled with cassiosome structures into the sea water like a mini grenade, so that the surrounding water bodies can sting people. In the other 4 related jellyfish, the researchers also found these cassiosome structures.