An estimated 100 fatalities a year.

Can be found in Northern Australia, Papua New Guinea, Malaysia, Indonesia, the Philippines, Thailand and Vietnam.

The jellyfish unwinds its coiled stinging tentacles, fires them at the victim and then pumps their venom to paralyse the unfortunate recipient, usually manifesting itself as cardiac arrest in humans.

If swimming in an area where there are known jellyfish, wear a sting-suit. However, if you are stung, get out of the water pronto and apply vinegar to any stings remaining embedded in the flesh to remove the venom, then brush or lift off using a credit card, stick or similar.

Few marine creatures are as mysterious and intimidating as jellyfish. Though easily recognized, this animal is often misunderstood. Bathers and beachcombers react with fear upon encountering this invertebrate but, in fact, most jellyfish in South Carolina waters are harmless. Jellyfish are members of the phylum Cnidaria. Members of this structurally simple marine group possess one of two body forms. Sea anemones, sea whips, corals and hydroids are polyps growing attached to rocks or other hard surfaces of the sea. Jellyfish and the Portuguese man-of- war are free-swimming medusae. Both body forms display radial symmetry with body parts radiating from a central axis. This symmetry allows jellyfish to respond to food or danger from any direction.

Most jellyfish pass through two different body forms during their life cycle. The first is the polyp stage; in this phase, the jellyfish takes the form of either a sessile stalk which catches passing food, or a similar free-floating configuration. The polyp's mouth and tentacles are located anteriorly, facing upwards. In the second stage, the jellyfish is known as a medusa. Medusae have a radially symmetric, umbrella-shaped body called a bell. The medusa's tentacles hang from the border of the bell.

Some Jellyfish are tiny, some can grow to be seven feet long or more, and some even actually have tentacles that stretch up to 100-120 feet and more. Often enough these miniatures and some of these monsters get washed ashore and die almost immediately. They cannot survive out of water as nearly 98 % of their body is water content. The body of a Jellyfish is usually transparent, gelatinous, shaped like a cup or a bell, and nearly completely filled with water. It can be quite heavy, over 450 pounds or more. It adheres to a radial symmetry, which means that if you halve a Jellyfish from any side, the two halves will always be equal. Jellyfish come in various colors of various brightness – light blue, deep blue, yellow, purple, lilac, orange red, etc - and look rather beautiful when see from afar. They glow in dark waters. Their very simple nervous system reacts to light and gravity.

Getting up-close and personal with a Jellyfish is really not a good idea. They tend to sting and, if the deadly venom doesn't kill you in three minutes, it'll make for several days or even weeks of severe pain. I'm not speaking from personal experience, of course. Some experiences are better off known second-hand. The sting is usually to stun prey or attackers. It comes from the stinging threads in the Nematocysts in the Cnidoblasts. The Cnidoblasts are the cells found on the tentacles. When the tentacles last out, the venom is injected into the prey or the attacker. Jellyfish Venom is being studied and used in Medical Research. It may help produce an antidote against other venoms and may also help in treating cancer and various other diseases.