Physalia utriculus also called Blue Bottle or (Indo-Pacific) Portuguese Man-of-War is a marine life form of the order

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...

 found in 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 allows it to float on the surface, propelled by currents, tides, and by a sail at the top of the bladder, which may be left or right-handed. 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, hanging below the float, provides the animal with a means of capturing prey.

P. utriculus is distinguished from the Atlantic Portuguese Man o' War

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...

 (Physalia physalis) by the smaller size of the float (six inches compared to twelve) and by having a single long fishing tentacle. Like its larger relative, P. utriculus often occurs in swarms.

Occurrence

P. utriculus is less widely distributed than the larger P. physalis, but it is the most common species on Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

n coasts. It is also found in Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

an waters, where it informally named ‘ili mane‘o or palalia.

Hazards

Individuals of P. utriculus sometimes become stranded on beaches, where their toxic nematocysts can remain potent for weeks or months in moist conditions. P. utriculus is responsible for most of the reported injuries Australian beaches, where up to 30,000 stings are reported. Most of the incidents are on the eastern coast, with only 500 or so in western and southern waters. Unlike P. physalis, no fatalities have been recorded for P. utriculus stings.

Biology

Each individual is actually a colony

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...

.