Wednesday, May 19, 2010
May 19, 2010 : Portuguese Man-o-War
The Portuguese Man o' War (Physalia physalis), also known as man of war, is a venomous marine invertebrate. The common name comes from a Portuguese war ship type of the 15th and 16th century, the caravel (in Portuguese, Caravela), which had triangular sails similar in outline to the bladder of the Portuguese Man o' War.
While the Portuguese Man o' War resembles a jellyfish, it is in fact a siphonophore – a colony of four kinds of minute, highly modified individuals, which are specialized polyps and medusoids. Each such zooid in these pelagic colonial hydroids or hydrozoans has a high degree of specialization and, although structurally similar to other solitary animals, are all attached to each other and physiologically integrated rather than living independently. Such zooids are specialized to such an extent that they lack the structures associated with other functions and are therefore dependent for survival on the others to do what the particular zooid cannot do by itself.