Physalia
Encyclopedia
Physalia is a genus of the order
Siphonophora
, colonies
of four specialized polyp
s and medusoids
that drift on the surface of the Indian
and Pacific ocean
s. A gas-filled bladder resembling a blue bottle
maintains their buoyancy, and a single long tentacle of venomous cnidocyte
s provide the animal with a means of capturing prey. A sail on their float, which may be left or right-handed, propel groups of Physalia about the sea. Individuals within these groups sometimes become stranded on beaches, where their toxic nematocysts can remain potent for weeks or months in moist conditions.
The species are distinguished by the size of the float (six inches compared to twelve) and by having a single, or several long fishing tentacle. The species Physalia utriculus
is given the common name Pacific Man o' war to distinguish it from the more widely distributed and larger Physalia physalis, the Portuguese Man o' war. No fatalities from envenomation are recorded for P. utriculus, in contrast to the larger species of the genus.
The genus was first described by Jean-Baptiste Lamarck
in 1801.
Ordo
Ordo may refer to:* A musical phrase constructed from one or more statements of a rhythmic mode pattern and ending in a rest* Ordo , is a nomadic palace for the Mongol aristocrats and the Turkic rulers...
Siphonophora
Siphonophora
Siphonophorae or Siphonophora, the siphonophores, are an order of the Hydrozoa, a class of marine invertebrates belonging to the phylum Cnidaria. They are colonial, but the colonies can superficially resemble jellyfish; although they appear to be a single organism, each specimen is actually a...
, colonies
Colony (biology)
In biology, a colony reference to several individual organisms of the same species living closely together, usually for mutual benefit, such as stronger defense or the ability to attack bigger prey. Some insects live only in colonies...
of four specialized polyp
Polyp
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are approximately cylindrical in shape and elongated at the axis of the body...
s and medusoids
Medusa (biology)
In biology, a medusa is a form of cnidarian in which the body is shaped like an umbrella, in contrast with polyps. Medusae vary from bell-shaped to the shape of a thin disk, scarcely convex above and only slightly concave below...
that drift on the surface of the Indian
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
and Pacific ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
s. A gas-filled bladder resembling a blue bottle
Portuguese Man o' War
The Portuguese Man o' War , also known as the Portuguese man-of-war, man-of-war, or bluebottle, is a jelly-like marine invertebrate of the family Physaliidae...
maintains their buoyancy, and a single long tentacle of venomous cnidocyte
Cnidocyte
A cnidocyte, cnidoblast, or nematocyte is a type of venomous cell unique to the phylum Cnidaria . The cnidocyte cell provides a means for them to catch prey and defend themselves from predators. Despite being morphologically simple, lacking a skeleton and usually being sessile, cnidarians prey on...
s provide the animal with a means of capturing prey. A sail on their float, which may be left or right-handed, propel groups of Physalia about the sea. Individuals within these groups sometimes become stranded on beaches, where their toxic nematocysts can remain potent for weeks or months in moist conditions.
The species are distinguished by the size of the float (six inches compared to twelve) and by having a single, or several long fishing tentacle. The species Physalia utriculus
Physalia utriculus
Physalia utriculus also called Blue Bottle or Portuguese Man-of-War is a marine life form of the order Siphonophora found in the Indian and Pacific oceans. A gas filled bladder allows it to float on the surface, propelled by currents, tides, and by a sail at the top of the bladder, which may be...
is given the common name Pacific Man o' war to distinguish it from the more widely distributed and larger Physalia physalis, the Portuguese Man o' war. No fatalities from envenomation are recorded for P. utriculus, in contrast to the larger species of the genus.
The genus was first described by Jean-Baptiste Lamarck
Jean-Baptiste Lamarck
Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck , often known simply as Lamarck, was a French naturalist...
in 1801.