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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 specialised polyps and medusoids.^[1]
A similar group of animals are the chondrophores.

Contents

Structure

Venom

Origin of the name

Footnotes

External links

Gallery

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 metres (30 feet) in length below the surface, although one metre (three feet) is the average. They sting and kill small sea creatures such as crayfish 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.

Venom

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 for weeks after detachment. The venom can travel up to the lymph nodes 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 between 2003 and 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 denaturing the toxins.^[2]
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 venom 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 conducted. Lifesavers around the world still use ice to treat the stings of this species.
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.
The sail portion is covered in a slime which counteracts the sting from the tentacles, and can be used for a quick cure. Look for a beached Man O' War, to get the slime from the sail, as attempting to touch one in the water is dangerous as you may come in contact with the tentacles. A normal jelly fish does not have this slime nor remedy.
The Loggerhead Turtle is apparently immune to Man O' War toxins, as the turtles are commonly seen feeding on the Man O' War. ^[3]

Origin of the name

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.

Footnotes

1. Grzimek, B., N. Schlager & D. Olendorf 2003. ''Grzimek's Animal Life Encyclopedia''. Thomson Gale.
2. A randomised controlled trial of hot water (45 degrees C) immersion versus ice packs for pain relief in bluebottle stings, Loten C, Stokes B, Worsley D, Seymour J, Jiang S, Isbistergk G, , , Med J Aust, 2006
3. Brodie: ''Venomous Animals'', Western Publishing Company 1989

External links

★ Siphonophores.org - General information on siphonophores, including the Portuguese man-of-war (Physalia)

★ Poisonous Animals: Blue bottle, Portuguese man-of-war (Physalia)

Gallery