Jellyfish and Portuguese Man of War

If you've ever felt the sting of a jellyfish, you know to steer clear. These graceful ocean dancers can ruin the best of beach days.

Jellyfish are common in all waters and the dreaded Portuguese man of war has occasionally found its way into the New England area. The Portuguese Man of War , also known as the bluebubble or bluebottle, is commonly thought of as a jellyfish but is actually a siphonophore —a colony of four sorts of polyps. The man of war has a large float, which may appear pink, blue or purple. Man o' war tentacles can be as long as 165 feet.

Each jellyfish tentacle can house millions of stinging cells, called nematocysts, which eject a barbed thread and sometimes poison. Contrary to popular belief, jellyfish do not consciously sting; barbs are automatically released when an object comes in contact with the cells. Dead jellyfish can also be hazardous to beachgoers.

Jellyfish stings can be serious, but are seldom fatal. Usually symptoms include a burning sensation, redness and welts, and swelling of the lymph nodes. In rare cases, a jellyfish sting may induce anaphylactic shock and require hospitalization.

If you are stung by a jellyfish:

Immediately alert the lifeguard on duty, who is trained in first aid and can call for assistance if necessary.
Brush off any tentacles using an object, do not use your hands unless you are wearing gloves.
Pour vinegar over the wound to disable the stinging cells. If vinegar is not available, rinse the wound with sea water or saline solution. (Research suggests that this may reduce the chance of the cells continuing to sting, as compared to rinsing the wound with fresh water.)
Ice the area to minimize pain.

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