Background
The skin of jellyfish contains so-called cnidocytes, which are used against prey and enemies when they come into contact with the skin. When appropriately irritated, a cnidocyst is ejected at high speed like a kind of harpoon, injecting a venom deep into the victim’s skin. This venom causes mild to fatal toxic and allergic reactions in humans. Numerous (home) remedies are recommended for treatment, including ice, hot water, vinegar, ammonia, formaldehyde, urine, sand, and specific antidotes.
Products
The best-known jellyfish repellent is Safe Sea (homepage), developed in Israel by the marine biologist couple Tami and Amit Lotan. It is also sold under the name “Care Plus Skin Sav Safe Sea 30+.” It is a sunscreen lotion that has an additional jellyfish repellent effect. According to our information, the lotion is currently not on sale in many countries. However, it can be imported from Germany, for example, via a pharmacy in many countries, or ordered via the Internet. The exact composition is not specified.
Effects
Jellyfish can not be chased away because they do not swim, but float. Jellyfish repellents exert their effects by preventing the stings of jellyfish. Safe Sea is based on the mucilaginous protective layer that covers clownfish – known from – and protects them from the bite of sea anemones, which have comparable cnidocytes to jellyfish. Clownfish live in sea anemones and therefore depend on this protection. The effectiveness of the jellyfish repellent is said to be based on four mechanisms. First, the lotion is hydrophobic and thus repels the tentacles. Second, it contains glycosaminoglycans, which fool the jellyfish into thinking it is its own tissue. Third, the lotion contains an inhibitor that binds to specific receptors on the jellyfish, and fourth, the magnesium and calcium ions it contains are thought to interfere with transmembrane signaling and harpoon firing. The lotion has been tested in clinical studies. We cannot comment on the actual efficacy.
Indications
For the prevention of jellyfish stings. The agents are also effective against some coral species and water lilies.
Dosage and precautions
According to the package insert.
