Jellyfish Stings And Their Trailing Tentacles

Jellyfish are free-swimming aquatic animals with gelatinous umbrella shaped bell and trailing tentacles. The bells assist them in movement by propelling them forward. Though they may seem harmless from outside, their tentacles can be used against their predators to inject toxins in the body of others, resulting in painful stings.

Jellyfish have special cells along their tentacles called cnidocytes. Attached with these cells are harpoon like structures full of venom, called nematocysts, which are a whip like hollow tubule and lies coiled under high osmotic pressure. When mechanical or chemical stimuli activate an external trigger, the lid of the cell pops open and sea water rushes in. This forces a microscopic harpoon, i.e, the nematocysts to shoot out and penetrate the skin of the victim in lesser time than what it takes for us to blink. The main cause of this discomfort is a type of protein called porin found in the venom of all jellyfish.

The Nematocysts can continue to fire even when the jellyfish becomes dead. So, it is quite important to remove them. Also, each cell can only fire once, so that they do not release nematocysts at every object that crosses their paths. The cnidocytes have both mechanical and chemical receptors that control the discharge. Hair cells detect touch while chemo-receptors sense the chemicals released by predators and prey. When the jellyfish encounters something that doesn’t have the appropriate chemical composition, the nematocysts does not fire. This adaptation ensures that they do not sting themselves.

While Jellyfish do not actively attack humans, when their tentacles come in contact with human flesh, stingers are released as a part of their natural defence mechanism. Most of the stings injected by these creatures are harmless to humans & do not possess any serious threats. But still, it is important to know methods in which its effect could be minimised in least time. Some remedies for jellyfish stings are described below.

The most easily available remedy for the stings is vinegar. Rinsing it with vinegar will usually render un-discharged nematocysts and make them inactive. Seawater can also help to remove residual nematocysts. But, we should be careful not to use freshwater, as any change in salt balance alters the osmotic pressure outside the nematocysts and will trigger the venom to fire. While most of the jellyfish stings are painful, some can be deadly too, for example the Sea-wasp Jellyfish.

So, keeping the above facts in mind, be careful , the next time you go to the shore.