Tuesday, June 29, 2010

Portuguese Man Of War

The Portuguese Man Of War, found in the world's warm water oceans,  is a very interesting animal indeed. First off, it is not a jellyfish. Even though it may look like a Jellyfish, and sting like a Jellyfish, (more on that later) it is a siphonophore, an animal that is actually made up of multiple organisms working together. How does this work exactly? Well, the Man Of War consists of four distinct parts, a gas-filled bladder (the pneumatophore), the tentacles which can detect and capture prey, a polyp containing digestive organs, and a polyp for reproduction.

Image from ImageQuest
The Man Of War takes its name from part #1- the gas-filled bladder. This polyp rests atop the water and has a sail like appearance ala a Portuguese battleship. This polyp can reach up to a foot in length and extend 6 inches above the water. The Man of War is only able to float and has very little control over its movements, which is why they tend to wash up on shore. The other three polyp types rest underneath the float. The long tentacles can reach lengths of 165ft, and are covered with nematocystic structures that sting and paralyze prey. Following that, muscles in the tentacles draw the meal up to the digestive polyps, which then cover and digest. The fourth polyp, as previously mentioned, relates to reproduction. The Man Of War (Men Of War?) fertilize externally, releasing the sperm and eggs into the sea.

The stingers of a Man Of War can be dangerous to humans, though are not often fatal. A sting causes immediate redness and burning pain followed by a string of lesions appeared at the sting site. Treatment for a sting involves the careful removal of any remaining tentacle pieces, rinsing with salt water, and the application of topical ointments. It can sometimes take 6-8 weeks for symptoms to fully disappear and more dangerous symptoms, including increased heart rate and difficulty breathing, can arise.

But enough of the scary stuff! The Portuguese Man Of War does have predators despite its nasty sting. Loggerhead Turtles have a fondness for them, as their skin is too thick to be affected by the stingers. There are also a handful of fish that are immune to the venom. This allows them to either eat the Man Of War, or to use it as a safe heaven to hide from other predators.

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