pleustonic

Physalia physalis is also known as the Portuguese man-of-war. It is a siphonophore, an animal that is made up of a colony of organisms working together, with individual polyps specialized for movement, catching prey, feeding and breeding. The name comes from the uppermost polyp, a gas filled bladder, or pneumatophore, which sits above the water and somewhat looks like an old warship at full sail.

Physalia physalis also known as the Portuguese Man O' War is commonly mistaken for a jellyfish. "The Portuguese man-of-war is a siphonophore, an animal that is made up of a colony of organisms working together. The name comes from the uppermost polyp, a gas filled bladder, or pneumatophore, which sits above the water and somewhat looks like an old warship at full sail. They are also, known as bluebottles for the purple-blue color of their pneumatophores" (A Portuguese man of war). The tentacles can extend to 165 feet, although, the average length is 30 feet (Portuguese Man-of War Physalia physalis).

 Each 'individual' Physalia physalis is composed of a group of polyps specialised for movement, catching prey, feeding and breeding. The individual polyps are dependent on each other for survival, each having a distinct role. A large, purple, gas filled float (the pheumatophore) reaching up to 30 cm in height allows Physalia physalis to float on the surface. The crest running along the top of the pheumatophore acts as a sail when raised. The jellyfish has many digestive polyps (gastrozooids), which hang down and secrete digestive juices onto the prey that has been caught and immobilised by the sting of the long, contractile tentacles (the dactylozooids). The tentacles may hang down several meters and have a bead-like appearance. Each 'bead' contains specialised stinging cells (nematocysts), which produces a debilitating sting.Even though individual Physalia physalis are not an unusual sight on the coasts of Britain and Ireland, mass standings are uncommon, occurring only 3 or 4 times a century (Wilson, 1947). The sting of Physalia physalis causes severe pain, skin lacerations, convulsions, respiratory distress and in some cases death (Williamson et al., 1996). The sting remains potent even after death and the tentacles should not be touched. Portuguese man owar are carnivorous feeding mainly on small crustaceans and larval fish (Kirkpatrick & Pugh, 1984).

Atlantic Europe, Azores Exclusive Economic Zone, Belgian Exclusive Economic Zone, Boulogne-sur-Mer, Bretagne, Canadian Exclusive Economic Zone [Pacific part], Cobscook Bay, Dunkerque, European waters (ERMS scope), FAO fishing area 67, Gulf of Maine, Gulf of Mexico, Mediterranean Sea, New Zealand Exclusive Economic Zone, North East Atlantic, North East Pacific, North Pacific, North West Atlantic, Plymouth, United Kingdom Exclusive Economic Zone, Villefranche-Sur-Mer, Wimereux

This species has been found in the Atlantic Ocean, the Pacific Ocean, the Indian Ocean, the Caribbean, and the Sargasso Sea. It floats on or near the surface of the water.

Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )

Tropical Atlantic Ocean

mainly (sub)tropical

Bay of Fundy; Virginian, south side of Cape Cod, and extending northward of the subprovince limit.

"Physalia physalis is found in tropical Atlantic waters and occasionally as far north as the Bay of Fundy and the Hebrides, and the Mediterranean Sea Portuguese Man o' war). They are reported abundantly off the Karachi coast in Pakistan, and are also common in the ocean off parts of Australia and New Zealand, particularly at the Sandspit and Hawkes Bay beaches during the months of June, July, and August. They are known to come ashore all along the northern Gulf of Mexico and both east and west coasts of Florida as well as around the Hawaiian Islands "(Portuguese Man o' war).

The Portuguese man-of-war is a floating hydrozoan. It is actually a colony consisting of four types of polyps: a pneumatophore, or float; dactylozooids, or tentacles; gastrozooids, or feeding zooids; and gonozooids which produce gametes for reproduction. Cnidocytes (stinging cells) are located in the tentacles. Their action is based on their individual osmotic and hydrostatic pressure. Sensory cells are numerous and are located in the epidermis of the tentacles and the region around the mouths. Generally, the sensory cells are receptors for touch and temperature.

The stinging cells, or cnidocytes, are the characteristic food-getting mechanisms of jellyfish and their close relatives. P. physalis has two sizes of cnidocytes, some small and others are large. These cells retain their potency long after an individual has been washed up along the shore, as many hikers along beaches have discovered to their dismay and discomfort.

Other Physical Features: ectothermic ; heterothermic ; venomous

Float to 15 cm, with crest; many long tentacles hang beneath. Habitat: floating at surface, occasionally inshore. Distribution: pantropical and warm-temperate. Sting severe, but rarely lethal. Specimens with a single main tentacle are thought by some to be a distinct species (Richmond, 1997).

The Portuguese man-of-war floats on the surface of tropical, marine waters. Generally, these colonies live in warm tropical and subtropical water such as along the Florida Keys and Atlantic coast, the Gulf Stream, the Gulf of Mexico, the Indian Ocean, the Caribbean Sea, and other warm areas of the Atlantic and Pacific oceans. They are especially common in the warm waters of the Sargasso Sea.

Habitat Regions: tropical ; saltwater or marine

Aquatic Biomes: pelagic ; coastal

pelagic

Depth range based on 17 specimens in 1 taxon.
Water temperature and chemistry ranges based on 8 samples.

Environmental ranges
  Depth range (m): 0 - 4976
  Temperature range (°C): -1.043 - 9.846
  Nitrate (umol/L): 18.472 - 31.346
  Salinity (PPS): 34.559 - 35.236
  Oxygen (ml/l): 3.475 - 6.713
  Phosphate (umol/l): 1.228 - 2.369
  Silicate (umol/l): 13.311 - 87.548

Graphical representation

Depth range (m): 0 - 4976

Temperature range (°C): -1.043 - 9.846

Nitrate (umol/L): 18.472 - 31.346

Salinity (PPS): 34.559 - 35.236

Oxygen (ml/l): 3.475 - 6.713

Phosphate (umol/l): 1.228 - 2.369

Silicate (umol/l): 13.311 - 87.548
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

 A pelagic warm water species driven into to shore by winds and currents.

"Men-of-war are most often found in warm, tropical and subtropical waters of the world’s oceans "(Portuguese Man-of-war Physalia physalis).

The Portuguese Man-of-War traps its food in its tentacles. It feeds mainly on fish fry (young fish) and small adult fish, and it also consumes shrimp, other crustaceans, and other small animals in the plankton. Nearly 70 to 90% of the prey are fish.

The tentacles, or dactylozooids, are the Man-of-War's main mechanisms for catching its prey and are also used for defense. P. physalis sometimes traps and consumes larger fishes such as flying fish and mackerel, though fishes as large as these generally manage to escape from the tentacles. The food of the Man-of-War is digested in its bag-like stomachs (gastrozooids), which are located along the underside of the float. The gastrozooids digest the prey by secreting enzymes that break down proteins, carbohydrates and fats. Each Man-of-War has multiple gastrozooids complete with individual mouths. After the food has been digested, any undigestible remains are pushed out through the mouths. The nourishment from the digested food is absorbed into the body and eventually circulates to the different polyps in the colony.

"They feed on prey including fish, fish larvae, cephalopods, chaetognaths, and leptocephalus (eel) larvae. Their tentacles have pigmented regions that resemble larval fish, small shrimp, and copepods to lure prey into their stinging net" (Hoover). Their tentacles tangle and stun their prey. After the prey is trapped, Physalia physalis contracts its tentacles to bring the prey into contact with polyps that secrete digestive enzymes to soften their catch (Hoover).

An "individual" is actually a colony of unisexual organisms. Every individual has specific gonozooids (sex organs or reproductive parts of the animals, either male or female). Each gonozooid is comprised of gonophores, which are little more than sacs containing either ovaries or testes.

Physalia are dioecious. Their larvae probably develop very rapidly to small floating forms.

Fertilization of P. physalis is assumed to occur in the open water, because gametes from the gonozooids are shed into the water. This may happen as gonozooids themselves are broken off and released from the colony. The release of gonozooids may be a chemical response occurring when groups of individuals are present in one locality. Critical density is probably required for successful fertilization. Fertilization may take place close to the surface. Most reproduction takes place in the fall, producing the great abundance of young seen during the winter and spring. It is not known what triggers this spawning cycle but it probably begins in the Atlantic Ocean.

Germ Cell Development

Each gonophore has a central spadix of multinucleate endodermal cells separating the coelenteron from a layer of germ cells. Covering each germ cell is a layer of ectodermal tissue. When gonophores first bud, the germ layer is a cap of cells on top of the endodermal spadix. As gonophores mature, the germ cells develop into a layer covering the spadix. Spermatogonia form a thick layer, while oogonia form a convoluted band several cells wide, but only one cell layer thick. There is very little cytoplasmic material within these cells, except during rare instances when cell division is occurring. Oogonia begin development at approximately the same size as spermatogonia, but become considerably larger. All oogonia are apparently formed at an early stage of gonophore development prior to the occurrence of enlargement. Interestingly, there appears to be yolk globules within the cytoplasm of most oogonia.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There is 1 barcode sequence available from BOLD and GenBank.   Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen.  Other sequences that do not yet meet barcode criteria may also be available.


Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 2
Species With Barcodes: 1

Genomic DNA is available from 2 specimens with morphological vouchers housed at British Antarctic Survey

Physalia physalis is not especially rare, and not considered to need special conservation effort at this time.

US Federal List: no special status

CITES: no special status

This species can hurt tourists and tourism in areas where it is common, due to stings (of neurotoxins) from its cnidocytes. Much money is spent each year to treat swimmers who have been stung by the tentacles of individuals that have washed up on beaches. The inflammatory response resulting from stings is due to the release of histamines from mast cells within the victim.

Negative Impacts: injures humans (bites or stings, venomous )

The Portuguese Man-of-War is eaten by some fish and crustaceans (e.g. the sand crab) that can be of commercial value.