A siphonophore or hydrozoan colony that is usually regarded as a jellyfish by non-biological people. It has a float, rather than a bell, and the tentacle(s) hang beneath. There are two main varieties: 1. Physalia utriculus. A single-tentacled species common in the warmer waters of the world, and especially common on the eastern seaboard of Australia where it causes some 10,000-odd stings each summer. No deaths have ever been reported, and usually it causes mild-to moderate skin pain and possibly some aching pains in the draining lymph glands in the leg or armpit. 2. Physalia physalis. The multi-tentacled species found world-wide, but commonly on both side of the North Atlantic. Stings are common on the eastern coast of the United States and have now caused 3 deaths as well as manysevere systemic symptoms. Specimens may have a float length of up to 25cm with tentacles up to 30m in length. Some severe systemic symptoms resemble a modified Irukandji syndrome with painful breathing, muscle cramps, anxietyand sweating.
Article Categories:Dictionary of Tropical Medicine