Cnidarians Codexery

Portuguese man o' war

A colonial siphonophore with a venomous sting and gas-filled sail.

Portuguese man o' war

Jules Verne Times Two · CC BY-SA 4.0

The Portuguese man o' war is a colonial marine hydrozoan, not a jellyfish, composed of many specialized zooids that function as a single organism.[1] It is found in the Atlantic, Indian, and Pacific oceans and is known for its painful sting.[2][3]

Last updated 2026-10-08 from the source article.

Quick Facts

Genus
Physalia
Species
physalis

Facts from the source article.

Key facts and history

Carl Linnaeus first described the species in 1758 as Holothuria physalis, and Jean-Baptiste Lamarck moved it to the genus Physalia in 1801.[4] The colony's most visible part is the gas-filled pneumatophore, which acts as both a float and a sail.[5] This pneumatophore can reach over 12 inches long and contains up to 13% carbon monoxide.[5] Long tentacles, typically about 10 meters but reaching over 30 meters, bear venomous nematocysts that paralyze prey.[6][7]

The animal drifts passively with winds and currents, and its left- or right-handed float shape causes it to sail at an angle to the wind.[3][8][9] The Portuguese caravel warship, a type of sailing vessel, is what the "man o' war" name references due to the animal's visual similarity to it.[10] Each colony is either male or female, a reproductive condition known as dioecy.[11] A planula, formed from a fertilized egg, creates new zooids through budding as it develops, which step by step forms a new colony.[12]

In humans, the stings produce intense pain that typically persists for one to three hours, and on very rare occasions, a sting can be lethal.[13]

What the cited sources add

The National Geographic account notes that man-o'-wars are found in groups of 1,000 or more floating in warm waters worldwide.[1] A 2008 BBC News report states that several potentially dangerous Portuguese man-of-war jellyfish washed up on the West Sussex coast.[14] A 2017 BBC article describes that the sting is extremely painful for humans and can be fatal in rare circumstances.[15] The Australian Museum account specifies that Physalia physalis is found in the Atlantic Ocean, while the bluebottle is found in the Indian and Pacific Oceans.[16]

References

  1. "Portuguese Man-of-War", National Geographic Animals, 11 November 2010. facts only, no text reused. nationalgeographic.com
  2. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: ; "Bluebottle", The Australian Museum; Stepan Bako, "Live Caravela Portuguesa on the beach", 2013-02-19 (we also read that source) en.wikipedia.org
  3. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: "Portuguese Man-of-War", National Geographic Society; Lee, "Drifting dynamics of the bluebottle (Physalia physalis)", Ocean Science, 2017-10-16, p. 1341–1351; "Dangerous jellyfish wash up", BBC News, 2008-08-18; "Man-of-war spotted along coast in Cornwall and Wales", BBC, 12 September 2017 (we also read that source) en.wikipedia.org
  4. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Carl von Linné, translated by William Turton, "Volume 4: Worms", Lackington, Allen, and Co, 1806; Peter Schuchert, "Physalia physalis (Linnaeus, 1758)", 2024; Lamarck, "Système des animaux sans vertèbres", by the author and Deterville, 1801, p. 355–356; Peter Schuchert, "Physalia Lamarck, 1801", 2024; Brandt, "Prodromus descriptionis animalium ab H. Mertensio in orbis terrarum circumnavigatione observatorum. Fascic. I., Polypos, Acalephas Discophoras et Siphonophoras, nec non Echinodermata continens", Recueil Actes de; Peter Schuc en.wikipedia.org
  5. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Bardi, "Taxonomic redescription of the Portuguese man-of-war, Physalia physalis (Cnidaria, Hydrozoa, Siphonophorae, Cystonectae) from Brazil", Iheringia, 2007, p. 425–433; Helmenstine, "Plentiful Portuguese Man-of-War Facts", ThoughtCo, 16 September 2019; "The Portuguese man-of-war (Physalia physalis)", Southeastern Taxonomic Regional Center; Munro, "Morphology and development of the Portuguese man of war, Physalia physalis", Scientific Reports, 2017-10-16, p. 15522; Wittenberg, "The Source of Carbon Monoxide in the Float of the P en.wikipedia.org
  6. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Munro, "Morphology and development of the Portuguese man of war, Physalia physalis", Scientific Reports, 2017-10-16, p. 15522; "Portuguese Man-of-War", National Geographic Society; NOAA, "What is a Portuguese Man o' War?", National Ocean Service, 27 July 2015 (original not read by us) en.wikipedia.org
  7. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Bardi, "Taxonomic redescription of the Portuguese man-of-war, Physalia physalis (Cnidaria, Hydrozoa, Siphonophorae, Cystonectae) from Brazil", Iheringia, 2007, p. 425–433; "Portuguese Man-of-War", National Geographic Animals, 11 November 2010 (we also read that source) en.wikipedia.org
  8. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Ferrer, "Relationship between dimorphism and drift in the Portuguese man-of-war", Continental Shelf Research, 2021-01-01; Ferrer, "Relationship between dimorphism and drift in the Portuguese man-of-war", Continental Shelf Research, 2021-01-01 (original not read by us) en.wikipedia.org
  9. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Totton, A. and Mackie, G. (1960) "Studies on Physalia physalis", Discovery Reports, 30: 301–40.; Woodcock, A. H. (1944) "A theory of surface water motion deduced from the wind-induced motion of the Physalia", J. Marine Res., 5: 196–205. (original not read by us) en.wikipedia.org
  10. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Greene, "Marine Science: Marine Biology and Oceanography", Amsco School Publications, 1998; ; ; (we also read that source) en.wikipedia.org
  11. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Munro, "Morphology and development of the Portuguese man of war, Physalia physalis", Scientific Reports, 2017-10-16, p. 15522; Munro, "Morphology and development of the Portuguese man of war, Physalia physalis", Scientific Reports, 2017-10-16, p. 15522; "The Portuguese man-of-war (Physalia physalis)", Southeastern Taxonomic Regional Center; Munro, "Morphology and development of the Portuguese man of war, Physalia physalis", Scientific Reports, 2017-10-16, p. 15522 (original not read by us) en.wikipedia.org
  12. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Munro, "Morphology and development of the Portuguese man of war, Physalia physalis", Scientific Reports, 2017-10-16, p. 15522 (original not read by us) en.wikipedia.org
  13. Wikipedia, "Portuguese man o' war" (CC BY-SA 4.0), which cites: Stein, "Fatal Portuguese man-o'-war (Physalia physalis) envenomation", Annals of Emergency Medicine, 1989, p. 312–315 (original not read by us) en.wikipedia.org
  14. "Dangerous jellyfish wash up", BBC News, 2008-08-18. facts only, no text reused. news.bbc.co.uk
  15. "Man-of-war spotted along coast in Cornwall and Wales", BBC, 12 September 2017. facts only, no text reused. bbc.com
  16. "Bluebottle", The Australian Museum. facts only, no text reused. australian.museum

Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Portuguese man o' war (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.

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