Ocean Jellyfish

There are 200 species of jellyfish known in the world and 70 of these are known to sting. The sting of a jellyfish can cause from a minor skin irritation to even death. You can class jellyfish as a planktonic marine member of a group of invertebrate animals. The jellyfish does not have a heart, head or a skeleton. Most of them are shaped like a bell or a mushroom, with tentacles trailing below their disk shaped bodies. Most of them are ranged in the size of 1 to 16 inches in diameter. There are big ones too, and they grow up to 6 1/2 feet in diameter. Their bodies are made up of two cellular layers with a connective tissue between them. This connective tissue is made up of a gelatinous substance, and is enlarged to form the buoyant transparent jelly-like body that we see.


Many of the jellyfish feed on small animals that they catch in their tentacles. Others are known to feed by just filtering out minute animals and plants such as Plankton, Nekton and loosened Benthos, as they are drifting around in the ocean. The life span of a jelly fish is generally known to be only for a few weeks. There are certain types who survive for a year or a little longer.

Jellyfish occur in all oceans and you will find many floating along the shoreline. The species is of the class Scyphozoa, and the term jellyfish is also used for certain Cindarians, that have a bell or disc shaped body, and other creatures such as Salps and Comb Jellies. The deadliest jellyfish is called the Sea Wasp or box jellyfish, and its sting is known to cause death in a human being. Its scientific name is Chironex Fleckeri, and its toxin is known to cause respiratory and neuromuscular paralysis, and cardiovascular collapse. Even a moderate sting from this type of jellyfish will cause death 20% of the time. These creatures are found in the ocean area covering Exmouth in western Australia to Gladstone in Queensland, and covering the area northward up to Malay.

Generally you should avoid going to areas where jellyfish is sighted or where there are dead ones lying on the beach. They sting via their tentacles, which have stinging cells called Nematocysts. When a person is stung you will see long red welt lines on the body. The sting is quite painful and the symptoms include a burning sensation, swelling of the Lymph nodes in the body and redness in the affected areas. The first aid for a jellyfish sting is to liberally douse vinegar on the affected areas. If any tentacles are visible then they should be removed by brushing them off with a towel or some other available material. Care should be taken that you do not directly touch the tentacles, as you also might get stung. For the pain apply a hot or a cold pack depending on the relief that it gives. For the bite of a Sea Wasp you need an Antivenin serum, which is available with Commonwealth Serum Laboratory of Melbourne.