Portuguese man o' war

Portuguese Man O' War
	File:Portuguese man of war.jpg
Scientific classification
Kingdom:	Animalia
Phylum:	Cnidaria
Class:	Hydrozoa
Order:	Siphonophora
Family:	Physaliidae
Genus:	Physalia
Species:	P. physalis
Binomial name
	Physalia physalis; (Linnaeus, 1758)

The Portuguese Man O' War (Physalia physalis), 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.

A similar group of animals are the chondrophores.

Structure

The Man Of War's float is bilaterally symmetrical with the tentacles at one end, while the chondrophores are radially symmetrical with the sail at an angle. Also the Man O' War has a siphon, while the chondrophores do not.

Bluebubble washed ashore at Batemans Bay, New South Wales, Australia; only the air bladder is readily visible

The Portuguese Man O' War has an air bladder; known also as a sail, that allows it to float on the surface of the ocean. It has no means of propulsion and is pushed by the winds and the current. The bladder is actually a single large polyp, called the pneumatophore. The sail is filled with air, but may build up a high concentration of carbon monoxide (up to 90%). The animal can deflate to submerge; however this is not its normal state, generally doing so only long enough to avoid a threat. The bladder must stay wet to ensure survival; every so often it dips itself under water.

Below the jelly dangle long tentacles, sometimes stretching to over ten meters in length. Tentacles as long as 55 m (180 ft) are known. These tentacles are individual polyps called dactylozooids. They stun and kill small sea creatures using poison-filled nematocysts and use muscles to draw the prey in to the gastrozooids, which are yet another different type of polyp that surround and digest it. Gonozooids, the fourth type of polyp, are responsible for reproduction.

Ecology

The man-of-war fish, whose name is derived from the Portuguese Man O' War, often lives within the man o' war's tentacles for protection.

Portuguese Man O' War are a very important source of food to sea turtles, which are immune to the poison. Sea slugs and sea snails floating on the water are also immune to the poison. The Portuguese Man O' War can be found on the coast of Africa, North America, Europe and Australia as well as in other areas of the world. Recently, the Man O' War has been found as far north as the town of Harwich, Massachusetts, on Cape Cod.

Poison

The sting from the tentacles is potentially dangerous to humans; these stings have been responsible for several deaths, but usually only cause excruciating pain. Detached tentacles and specimens washed up on shore can sting just as painfully as the full creature in the water. The venom can travel up to the lymph glands and may cause, depending on the amount of venom, more intense pain. In extreme cases medical attention is necessary.

According to a study done by Dr. Geoffrey Isbister of Newcastle, Australia's Mater Hospital in 2003 through 2005, the best treatment for a sting is to apply hot water to the affected area. Hot water used in the study was fixed at 45 degrees Celsius (113 Fahrenheit). The hot water eases the pain of a sting by degrading the toxins. [1]

Applying ice to the area of the sting is also a fairly effective way to suppress the pain. Ice works by making the toxins less active and reduces the sensation and therefore pain of the area of skin around the ice. Additionally, ice constricts blood vessels, reducing the speed at which the poison travels to other parts of the body, including the brain; heat has an opposite effect. It was originally thought that applying ice was the best way of dealing with Man o' War stings before the study was done. Lifesavers around the world still use ice to treat the stings of this species.

Ointments that are specifically designed to treat Man o' War stings seem to have little effect.

The use of vinegar to treat stings is controversial. It appears that vinegar can make the sting more painful in some cases, while other victims report relief after applying vinegar. One should never apply vinegar while the tentacle is still attached to the body, as this will cause the stinging cells to inject more venom.

It is often confused with a jellyfish, which is incorrect and may lead to improper treatment of stings, as the poison is different. A second sting may lead to an allergic reaction.

Origin of the name

The Man O' War is named for its air bladder, which looks similar to a man o'war under sail. [2] [3]

Portuguese Man o' War spotted at Biscayne National Park

External links