Portuguese Man o' War

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Portuguese Man O' War
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, bluebottle or the man-of-war or the portuguese man of war, is commonly thought of as a jellyfish but is actually a siphonophore—a colony of specialized polyps and medusoids.^[1]

A similar group of animals are the chondrophores.

Contents 1 Structure 2 Venom 3 Predators 4 About It 5 Footnotes 6 External links 7 Gallery

[edit] Structure

The Man O' 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.

The Portuguese Man O' War has an air bladder, known as the pneumatophore or 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 sail is filled with air, but may build up a high concentration of carbon dioxide (up to 90%). The bladder must stay wet to ensure survival; every so often it may roll slightly to wet the surface of the float. To escape a surface attack, the pneumatophore can be deflated allowing the Man O' War to briefly submerge.

Below the main body dangle long tentacles, sometimes reaching ten meters (33 feet) in length below the surface, although one meter (three feet) is the average. They sting and kill small sea creatures such as small fish and shrimp using venom-filled nematocysts, then draw the prey in to the gastrozooids, another type of polyp that surrounds and digest it. Gonozooids are responsible for reproduction.

[edit] Venom

This section may contain original research or unverified claims. Please improve the article by adding references. See the talk page for details. (February 2008)

The sting from the tentacles is dangerous to humans. These stings usually cause excruciating pain, and have even been the cause of several deaths. Detached tentacles and specimens which wash up on shore can sting just as painfully as the intact creature in the water for weeks after their detachment. The venom can travel up to the lymph nodes and may cause, depending on the amount of venom, more intense pain. Medical attention is usually necessary, especially in extreme cases.

Research suggests that the best treatment for a sting is to apply hot water (45°C/113°F) to the affected area, which eases the pain of a sting by denaturing the toxins.^[2] Ice is also effective at suppressing the pain through reducing the activity of the toxins and reducing the sensation and therefore pain of the area of skin around the ice. Additionally, ice constricts blood vessels, reducing the speed at which the venom travels to other parts of the body.

The Portuguese Man O' War is often confused with a jellyfish, which is incorrect and may lead to improper treatment of stings, as the venom is different. A second sting may lead to an allergic reaction.

[edit] Predators

The Loggerhead Turtle, which is apparently immune to Man O' War toxins, is commonly seen feeding on the Man O' War.^[3]

The sea slug Glaucus atlanticus also feeds on the Man O' War.^[4]

[edit] About It

Anyone unfamiliar with the biology of the venomous Portuguese man-of-war would likely mistake it for a jellyfish. Not only is it not a jellyfish, it's not even an "it," but a "they." The Portuguese man-of-war is a siphonophore, an animal made up of a colony of organisms working together.

The man-of-war comprises four separate polyps. It gets its name from the uppermost polyp, a gas-filled bladder, or pneumatophore, which sits above the water and somewhat resembles an old warship at full sail. Man-of-wars are also known as bluebottles for the purple-blue color of their pneumatophores.

The tentacles are the man-of-war's second organism. These long, thin tendrils can extend 165 feet (50 meters) in length below the surface, although 30 feet (10 meters) is more the average. They are covered in venom-filled nematocysts used to paralyze and kill fish and other small creatures. For humans, a man-of-war sting is excruciatingly painful, but rarely deadly. But beware—even dead man-of-wars washed up on shore can deliver a sting.

Muscles in the tentacles draw prey up to a polyp containing the gastrozooids or digestive organisms. A fourth polyp contains the reproductive organisms.

Man-of-wars are found, sometimes in groups of 1,000 or more, floating in warm waters throughout the world's oceans. They have no independent means of propulsion and either drift on the currents or catch the wind with their pneumatophores. To avoid threats on the surface, they can deflate their air bags and briefly submerge.==Etymology== The Portuguese Man O' War (named caravela-portuguesa in Portuguese) is named for its air bladder, which looks similar to the sails of the Portuguese fighting ship (man-of-war) Caravela redonda (an armed 4-sail caravel), of the 14th and 15th centuries.

[edit] Footnotes

[edit] External links

• Siphonophores.org - General information on siphonophores, including the Portuguese man-of-war (Physalia)
• Poisonous Animals: Blue bottle, Portuguese man-of-war (Physalia)
• (Physalia)

[edit] Gallery

Portuguese Man O'War Gulf Shores Alabama May 2008	Portuguese Man O' War, March 2008 Miami Beach, Florida	Portuguese Man O'War on Delray Beach, Florida	Portuguese Man O' War washed ashore at Batemans Bay, New South Wales, Australia; only the air bladder is readily visible
Portuguese Man O' War washed ashore on Surfer's Paradise, on the Gold Coast in Australia	Portuguese Man O' War spotted at Biscayne National Park, Florida	Portuguese Man O' War washed ashore in Melbourne, Florida	Portuguese Man O'War captured alive in Mayaro Beach, Trinidad and Tobago
Physalia physalis on the shore in Karachi, Pakistan	Portuguese Man O' War washed ashore in Palm Beach, Florida	'Blue Bottle Jellyfish' at Tawharanui Open Sanctuary,New Zealand	Portuguese Man O' War washed ashore on Horseshoe Bay Beach, Bermuda