Certain species of jellyfish can in fact be deadly to humans. However most are harmless but may be known to sting a little. There are a few jellyfish that can kill a human being in only a matter of minutes. Among them is the box jellyfish that can kill an adult human in a mere 4 or 5 minutes.

Jellyfish are usually passive drifters who use their tentacles to catch small prey, however they can pack on quite a nasty nip that will result in excruciating pain depending on the species. The box jellyfish (mentioned above) is actually one of the most venomous marine creatures in the world and can string and kill a man within minutes. Most fatalities occur just following a brush with a toxic jellyfish like this.

If an individual is going to be swimming in an area where there are known jellies, it is recommended that they wear a sting suit. However, if you do happen to get stung somehow it is important to get out of the water immediately and apply vinegar to any stings remaining embedded in the flesh. This should be done in order to remove the venom and then it should be brushed off or lifted off using a stick, or something of the like.

The best word of advice is to stay as far away from jellyfish as possible! This is the best way to ensure your safety.

The species of jellyfish known as turritopsis nutricula may be the only animal in the world to become immortal. This creature is a hydrozoan (a taxonomic class of very small, predatory animals which can be solitary or colonial and which mostly live in saltwater). This hydrozoan’s jellyfish form can revert back to the polyp stage (its first stage of life) after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage. It does this through the cell development process of transdifferentiation. Cell transdifferentiation is when the jellyfish alters the differentiated state of the cell and transforms it into a new cell. During this process the medusa of the jellyfish is transformed into the polyps of a new polyp colony.

When the jellyfish transforms its umbrella first reverts itself and then the tentacles and mesoglea break down. The reverted medusa then attached itself to the substrate by the end that had been at the opposite end of the umbrella and starts giving rise to new polyps to form the new colony. Theoretically speaking, this process could go on forever effectively rendering this particular species of jellyfish biologically immortal. Although in nature, it is very rare for turritopsis to ever revert to the polyp stage as many succumb to predation or disease during the plankton stage.

It has been said that it is currently impossible to estimate the age of an individual jellyfish as no single specimen has ever really been observed for an extended period of time. And even if this species does have the potential for immortality, there is no laboratory evidence of many generations surviving from any individual. Scientists are still trying to study this magnificent creature to discover how it is able to reverse the aging process. Because they are able to escape death, the number of this particular species is continuing to grow and they are now found worldwide in oceans around the globe rather than just their native Caribbean waters.

Jellyfish do not have enough adaptations to live outside of water. In order to do this they would need an excretory system for the osmoregulation and a true ambulacral system. Jellyfish typically only live for about a year and if they do not live for about a year it is most likely because they were eaten by a fish, turtle, bird or something like that. Another way they can die early is if they are not in salt water. Jellyfish need saltwater in order to stay alive.

When a jellyfish gets washed up to shore it cannot get back into the water. If you spot one lying on the beach you should never touch it as it can still sting you, even if it appears to be dead or actually is dead. Something that is rather interesting though is that when jellyfish wash ashore, they melt. All that will be left is some of its skin.

There are approximately 2,000 species of jellyfish worldwide yet only less than 100 or so are actually thought of as dangerous and can cause harm to human and animal life. It is true that jellyfish can still sting even after they have died. This is because jellyfish do not consciously sting. Each of their tentacles can be equipped with stinging cells that automatically release venomous barbs when the cells come into contact with an object. This is done as a defense mechanism to keep jellies safe from predators. It does not work on sea turtles however. Interestingly enough these turtles can eat jellyfish without getting stung or poisoned.

What may come as a surprise to most is that jellyfish can even still sting you when they have died, washed up on a beach and dried up. The tentacles (even if they are no longer connected to the jellyfish) can still sting and it is for this reason that these jellyfish or their parts should never be picked up or stepped on. Some jellyfish are more poisonous than others; however all can cause quite a bit of pain if they sting an individual.

Very few jellyfish are actually edible. The scyphozoan jellyfish (about 12 of the 85 species or so) are one of the more popular jellyfish often harvested for food. Most of the harvesting takes place in locations such as Southeast Asia. Fisheries have also begun harvesting the American cannonball jellyfish located along the southern Atlantic coast of the United States and in the Gulf of Mexico to export to Asia because they are larger with more rigid bodies and their toxins are harmless to humans, making them a favored meal when compared to other types of jellyfish.

Traditional processing methods are carried out by a “jellyfish master” and involve a multi-phase procedure that takes 20-40 days. During this procedure the gonads and mucous membranes are removed, and then the umbrella and oral arms are treated with a mixture of table salt and alum then compressed. Processing reduces liquefaction, odor, and the growth of spoilage organisms and also makes the fish drier and more acidic which in turn produces a crunchy, crisp texture.

Jellyfish that are prepared this way retain 7-10% of their original weight the processed product contains approximately 94% water and 6% protein. Freshly processed jellyfish often has a white creamy color and will turn yellow or brown during prolonged storage. Despite their high water content, these creatures are actually quite nutritious. They are almost completely free of cholesterol, calories, carbohydrates and saturated fats.

In China, jellyfish are processed by being desalted first by being soaked in water overnight and then eaten raw or cooked. The jellyfish dish is often served shredded up with a dressing of oil, soy sauce, vinegar, and sugar. Or it is sometimes served as a salad with vegetables. In Japan, cured jellyfish are rinsed and then cut into strips and served along with vinegar as an appetizer. Desalted, ready to eat products are also another popular choice available for consumption. Some individuals prefer to cook jellyfish and then let it sit in cold water for about 8 hours, blanch it and add some seasonings to it. It is very important to keep cooked and raw jellyfish apart from each other. Even though they mostly contain water, they are still able to hold the same type of bacteria as other meats.