Portuguese Man o' War
Encyclopedia
The Portuguese Man o' War (Physalia physalis), also known as the Portuguese man-of-war, man-of-war, or bluebottle, is a jelly
-like marine
invertebrate
of the family Physaliidae. The name "man-of-war" is taken from the man-of-war, a 16th century English armed sailing ship which was based on an earlier Portuguese vessel.
Despite its outward appearance, the Man o' War is not a true jellyfish
but a siphonophore, which differ from jellyfish in that they are not actually a single creature, but a colonial organism
made up of many minute individuals called zooid
s. Each of these zooid
s is highly-specialized and, although structurally similar to other solitary animals, are attached to each other and physiologically integrated to the extent that they are incapable of independent survival.
The Man o' War is found in warm water seas floating on the surface of open ocean, its air bladder keeping it afloat and acting as a sail while the rest of the organism hangs below the surface. It has no means of self-propulsion and is entirely dependent on winds, currents, and tides. It is most common in the tropical and subtropical regions of the Pacific and Indian oceans, but can drift outside of this range on warm currents such as the Atlantic Gulf Stream.
and the Hebrides
.
In the Mediterranean Sea, the Man o' War was first spotted off the coast of Spain
, and then later in Corsica
. In 2010, sightings of the Man o' War were recorded around Malta
in the Mediterranean. In the summer of 2009, Pembrokeshire
County Council warned bathers in its waters that the organisms had been sighted in Welsh
waters. In Ireland, there were dozens of confirmed sightings (in 2009–2010), from Termonfeckin
in County Louth
to the coast of County Antrim On the other side of the Atlantic, they wash ashore along the northern Gulf of Mexico
and east and west coasts of Florida
. An abundance of Portuguese Men o' War can be found in the waters of Costa Rica
, especially in March and April, while they are also found off of Guyana
. They wash up on the shore during certain months of the year. They are reported abundantly in the waters near Karachi
, Pakistan
in the summer months, and are also common in the ocean off parts of Australia
, where they are known more commonly as 'blue-bottles', and New Zealand
. During these months, they come ashore in the Gulf of California
after rain, where they are known as agua(s) mala(s) by locals. They are also frequently found along the east coast of South Africa
, (particularly during winter storms if the wind has been blowing steadily on-shore for several hours), as well as around the Hawaiian Islands
.
Strong onshore winds may drive them into bays or onto beaches. It is rare for only a single Portuguese Man o' War to be found; the discovery of one usually indicates the presence of many as they are usually congregated by currents and winds into groups of thousands.
Attitudes to the presence of the Portuguese Man o' War vary around the world. Given their sting however, they must always be treated with caution, and the discovery of a number of men o' war washed up on a beach might lead to the closure of the whole beach.
. The sail may be 9 to 30 centimetres (4 to 12 in) long and may extend as much as 15 centimetres (6 in) above the water. The gas which the Portuguese Man o' War secretes into its sail has approximately the same composition as the atmosphere, but may build up a high concentration of carbon dioxide
(up to 90%). The sail must stay wet to ensure survival and occasionally they may roll slightly to wet the surface of the sail. To escape a surface attack, the sail can be deflated allowing the Man o' War to briefly submerge.
The other three polyps are known as: dactylozooid (defence), gonozooid (reproduction), and gastrozooid (feeding) These polyps are "clustered". The dactylzooids make up the tentacles that are typically 10 metres (30 ft) in length but can be up to 50 metres (165 ft). The long tentacles "fish" continuously through the water and each tentacle bears stinging venom-filled nematocysts (coiled thread-like structures), which sting and kill small sea creatures such as small fish and shrimp. Contractile cells in each tentacle work to drag prey into range of the digestive polyps, the gastrozooids, another type of polyp that surround and digest the food by secreting enzymes that break down proteins, carbohydrates and fats. Gonozooids are responsible for reproduction.
A small fish, Nomeus gronovii, are nearly immune to the poison from the stinging cells, and can live among the tentacles. They have a commensal symbiotic relationship, i.e. a relationship beneficial for the symbiont, with no negative or pathogenic effect on the host. The tiny fish often "snack" upon the tendrils as well, changing the nature of the relationship to parasitic.
The Portuguese Man o' War's float is bilaterally symmetrical with the tentacles at one end, whereas by contrast the chondrophore
s are radially symmetrical with the sail at an angle or in the centre. Also, the Portuguese Man o' War has a siphon, while the chondrophores do not.
each summer, particularly on the east coast, with some others occurring off the coast of South Australia
and Western Australia
.
The stinging venom-filled nematocysts in the tentacles of the Portuguese Man o' War can paralyze small fish and other prey. Detached tentacles and dead specimens (including those that wash up on shore) can sting just as painfully as the live creature in the water, and may remain potent for hours or even days after the death of the creature or the detachment of the tentacle.
Stings usually cause severe pain
to humans, leaving whip-like, red welts on the skin that normally last 2 or 3 days after the initial sting, though the pain should subside after about an hour. However, the venom can travel to the lymph nodes and may cause, depending on the amount of venom, a more intense pain. A sting may lead to an allergic reaction. There can also be serious effects, including fever, shock, and interference with heart and lung function. Stings may also cause death, although this is extremely rare. Medical attention may be necessary, especially where pain persists or is intense, if there is an extreme reaction, the rash worsens, a feeling of overall illness develops, a red streak develops between swollen lymph nodes and the sting, or if either area becomes red, warm and tender.
Research suggests that in the normal course the best treatment for a Portuguese Man o' War sting is:
If eyes have been affected they should be irrigated with copious amounts of room temperature tap water for at least 15 minutes and if vision blurs, or the eyes continue to tear, hurt, swell, or are light sensitive after irrigating, or there is any concern, a doctor should be seen as soon as possible.
Vinegar is not recommended for treating stings. Vinegar dousing increases toxin delivery and worsens symptoms of stings from the nematocysts of P. physalis, the larger Man o' War species. Vinegar has also been confirmed to provoke hemorrhaging when used on the less severe stings of nematocysts of smaller species.
The Portuguese Man o' War is often confused with jellyfish
by its victims, which may lead to improper treatment of stings, as the venom differs from that of true jellyfish.
feeds on the Portuguese Man o' War, a common part of the Loggerhead's diet. The turtle's skin is too thick for the sting to penetrate.
The sea slug Glaucus atlanticus
also feeds on the Portuguese Man o' War, as does the violet snail Janthina janthina
.
The blanket octopus
is immune to the venom of the Portuguese Man o' War, and they have been known to rip off its tentacles and use them for defensive purposes.
The Ocean Sunfish
's primary diet consists of jellyfish, but it can also consume Portuguese Man o' War. Because of the Ocean Sunfish's size and bulk, it must consume large amounts of these animals to compensate for their low nutritional value.
The Portuguese Man-of-War is classified as a carnivore. Using its venomous tentacles, a Man o' War traps and paralyzes its prey. Typically, Man o' War feed upon small aquatic organisms, such as fish and plankton.
, clownfish
and yellow jack
, species that are rarely found elsewhere. The clownfish
can swim among the tentacles with impunity, possibly due to its mucus that does not trigger the nematocysts. The shepherd fish
seems to avoid the larger, stinging tentacles, but feeds on the smaller tentacles beneath the gas bladder. These fish benefit from the shelter from predators provided by the stinging tentacles, and for the Portuguese Man o' War the presence of these species may attract other fish to feed on.
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
-like marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
of the family Physaliidae. The name "man-of-war" is taken from the man-of-war, a 16th century English armed sailing ship which was based on an earlier Portuguese vessel.
Despite its outward appearance, the Man o' War is not a true jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
but a siphonophore, which differ from jellyfish in that they are not actually a single creature, but a colonial organism
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...
made up of many minute individuals called zooid
Zooid
A zooid or zoöid is a single animal that is part of a colonial animal. The zooids can either be directly connected by tissue or share a common exoskeleton...
s. Each of these zooid
Zooid
A zooid or zoöid is a single animal that is part of a colonial animal. The zooids can either be directly connected by tissue or share a common exoskeleton...
s is highly-specialized and, although structurally similar to other solitary animals, are attached to each other and physiologically integrated to the extent that they are incapable of independent survival.
The Man o' War is found in warm water seas floating on the surface of open ocean, its air bladder keeping it afloat and acting as a sail while the rest of the organism hangs below the surface. It has no means of self-propulsion and is entirely dependent on winds, currents, and tides. It is most common in the tropical and subtropical regions of the Pacific and Indian oceans, but can drift outside of this range on warm currents such as the Atlantic Gulf Stream.
Habitat and location
The Portuguese Man o' War lives at the surface of the ocean. The gas-filled bladder, or pneumatophore, remains at the surface, while the remainder is submerged. Since the Man o' War has no means of propulsion, it is moved by a combination of winds, currents, and tides. Although they can be found anywhere in the open ocean (especially warm water seas), they are most commonly found in the tropical and subtropical regions of the Pacific and Indian oceans, and the northern Atlantic Gulf Stream. The Man o' War has been found as far north as the Bay of FundyBay of Fundy
The Bay of Fundy is a bay on the Atlantic coast of North America, on the northeast end of the Gulf of Maine between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state of Maine...
and the Hebrides
Hebrides
The Hebrides comprise a widespread and diverse archipelago off the west coast of Scotland. There are two main groups: the Inner and Outer Hebrides. These islands have a long history of occupation dating back to the Mesolithic and the culture of the residents has been affected by the successive...
.
In the Mediterranean Sea, the Man o' War was first spotted off the coast of Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, and then later in Corsica
Corsica
Corsica is an island in the Mediterranean Sea. It is located west of Italy, southeast of the French mainland, and north of the island of Sardinia....
. In 2010, sightings of the Man o' War were recorded around Malta
Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
in the Mediterranean. In the summer of 2009, Pembrokeshire
Pembrokeshire
Pembrokeshire is a county in the south west of Wales. It borders Carmarthenshire to the east and Ceredigion to the north east. The county town is Haverfordwest where Pembrokeshire County Council is headquartered....
County Council warned bathers in its waters that the organisms had been sighted in Welsh
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
waters. In Ireland, there were dozens of confirmed sightings (in 2009–2010), from Termonfeckin
Termonfeckin
Termonfeckin or Termonfechin is a small village and townland in County Louth, Ireland. It is within the parish of the same name, and lies north-east of Drogheda. The population of the village was 653 as per census 2006.-History:...
in County Louth
County Louth
County Louth is a county of Ireland. It is part of the Border Region and is also located in the province of Leinster. It is named after the town of Louth. Louth County Council is the local authority for the county...
to the coast of County Antrim On the other side of the Atlantic, they wash ashore along the northern Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
and east and west coasts of Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
. An abundance of Portuguese Men o' War can be found in the waters of Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, especially in March and April, while they are also found off of Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
. They wash up on the shore during certain months of the year. They are reported abundantly in the waters near Karachi
Karachi
Karachi is the largest city, main seaport and the main financial centre of Pakistan, as well as the capital of the province of Sindh. The city has an estimated population of 13 to 15 million, while the total metropolitan area has a population of over 18 million...
, Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
in the summer months, and are also common in the ocean off parts of 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...
, where they are known more commonly as 'blue-bottles', and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. During these months, they come ashore in the Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
after rain, where they are known as agua(s) mala(s) by locals. They are also frequently found along the east coast of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, (particularly during winter storms if the wind has been blowing steadily on-shore for several hours), as well as around the Hawaiian Islands
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...
.
Strong onshore winds may drive them into bays or onto beaches. It is rare for only a single Portuguese Man o' War to be found; the discovery of one usually indicates the presence of many as they are usually congregated by currents and winds into groups of thousands.
Attitudes to the presence of the Portuguese Man o' War vary around the world. Given their sting however, they must always be treated with caution, and the discovery of a number of men o' war washed up on a beach might lead to the closure of the whole beach.
Structure
The Portuguese Man o' War is composed of four types of polyp. One of the polyps, a gas-filled bladder called the pneumatophore (commonly known as the marissa or sail), enables the organism to float. This sail is translucent and tinged blue, purple, pink or mauveMauve
Mauve is a pale lavender-lilac color, one of many in the range of purples. The color mauve is named after the mallow flower....
. The sail may be 9 to 30 centimetres (4 to 12 in) long and may extend as much as 15 centimetres (6 in) above the water. The gas which the Portuguese Man o' War secretes into its sail has approximately the same composition as the atmosphere, but may build up a high concentration of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
(up to 90%). The sail must stay wet to ensure survival and occasionally they may roll slightly to wet the surface of the sail. To escape a surface attack, the sail can be deflated allowing the Man o' War to briefly submerge.
The other three polyps are known as: dactylozooid (defence), gonozooid (reproduction), and gastrozooid (feeding) These polyps are "clustered". The dactylzooids make up the tentacles that are typically 10 metres (30 ft) in length but can be up to 50 metres (165 ft). The long tentacles "fish" continuously through the water and each tentacle bears stinging venom-filled nematocysts (coiled thread-like structures), which sting and kill small sea creatures such as small fish and shrimp. Contractile cells in each tentacle work to drag prey into range of the digestive polyps, the gastrozooids, another type of polyp that surround and digest the food by secreting enzymes that break down proteins, carbohydrates and fats. Gonozooids are responsible for reproduction.
A small fish, Nomeus gronovii, are nearly immune to the poison from the stinging cells, and can live among the tentacles. They have a commensal symbiotic relationship, i.e. a relationship beneficial for the symbiont, with no negative or pathogenic effect on the host. The tiny fish often "snack" upon the tendrils as well, changing the nature of the relationship to parasitic.
The Portuguese Man o' War's float is bilaterally symmetrical with the tentacles at one end, whereas by contrast the chondrophore
Chondrophore
The chondrophores or porpitids are a small and very unusual group of hydrozoans today classified as family Porpitidae. Though it derives from an outdated name for this lineage , some still find the term "chondrophore" useful as a synonym to "porpitid" in discussions of the three genera contained...
s are radially symmetrical with the sail at an angle or in the centre. Also, the Portuguese Man o' War has a siphon, while the chondrophores do not.
Venom
The Portuguese Man o' War is responsible for up to 10,000 human stings in AustraliaAustralia
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...
each summer, particularly on the east coast, with some others occurring off the coast of South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
and Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
.
The stinging venom-filled nematocysts in the tentacles of the Portuguese Man o' War can paralyze small fish and other prey. Detached tentacles and dead specimens (including those that wash up on shore) can sting just as painfully as the live creature in the water, and may remain potent for hours or even days after the death of the creature or the detachment of the tentacle.
Stings usually cause severe pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
to humans, leaving whip-like, red welts on the skin that normally last 2 or 3 days after the initial sting, though the pain should subside after about an hour. However, the venom can travel to the lymph nodes and may cause, depending on the amount of venom, a more intense pain. A sting may lead to an allergic reaction. There can also be serious effects, including fever, shock, and interference with heart and lung function. Stings may also cause death, although this is extremely rare. Medical attention may be necessary, especially where pain persists or is intense, if there is an extreme reaction, the rash worsens, a feeling of overall illness develops, a red streak develops between swollen lymph nodes and the sting, or if either area becomes red, warm and tender.
Research suggests that in the normal course the best treatment for a Portuguese Man o' War sting is:
- To avoid any further contact with the Portuguese Man o' War and to carefully remove any remnants of the creature from the skin (taking care not to touch them directly with fingers or any other part of the skin to avoid secondary stinging); then
- To apply salt water to the affected area (not fresh water, which tends to make the affected area worse). Follow up with the application of hot water (45 °C/113 °F) to the affected area, which eases the pain of a sting by denaturingDenaturation (biochemistry)Denaturation is a process in which proteins or nucleic acids lose their tertiary structure and secondary structure by application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent , or heat...
the toxins.
If eyes have been affected they should be irrigated with copious amounts of room temperature tap water for at least 15 minutes and if vision blurs, or the eyes continue to tear, hurt, swell, or are light sensitive after irrigating, or there is any concern, a doctor should be seen as soon as possible.
Vinegar is not recommended for treating stings. Vinegar dousing increases toxin delivery and worsens symptoms of stings from the nematocysts of P. physalis, the larger Man o' War species. Vinegar has also been confirmed to provoke hemorrhaging when used on the less severe stings of nematocysts of smaller species.
The Portuguese Man o' War is often confused with jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
by its victims, which may lead to improper treatment of stings, as the venom differs from that of true jellyfish.
Predators and prey
The Loggerhead TurtleLoggerhead Sea Turtle
The loggerhead sea turtle , or loggerhead, is an oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around long when fully grown, although larger specimens of up to have been discovered...
feeds on the Portuguese Man o' War, a common part of the Loggerhead's diet. The turtle's skin is too thick for the sting to penetrate.
The sea slug Glaucus atlanticus
Glaucus atlanticus
Glaucus atlanticus is a species of small-sized blue sea slug, a pelagic aeolid nudibranch, a marine gastropod mollusk in the family Glaucidae...
also feeds on the Portuguese Man o' War, as does the violet snail Janthina janthina
Janthina janthina
Janthina janthina, common name the common purple snail, is a species of holoplanktonic sea snail, a marine gastropod mollusk in the family Janthinidae, the violet snails or purple storm snails.-Distribution:...
.
The blanket octopus
Blanket octopus
Tremoctopus is a genus of pelagic cephalopods, containing four species that occupy surface to mid-waters in subtropical and tropical oceans. They are commonly known as blanket octopuses, in reference to the long transparent webs that connect the dorsal and dorsolateral arms of the adult females...
is immune to the venom of the Portuguese Man o' War, and they have been known to rip off its tentacles and use them for defensive purposes.
The Ocean Sunfish
Ocean sunfish
The ocean sunfish, Mola mola, or common mola, is the heaviest known bony fish in the world. It has an average adult weight of . The species is native to tropical and temperate waters around the globe. It resembles a fish head with a tail, and its main body is flattened laterally...
's primary diet consists of jellyfish, but it can also consume Portuguese Man o' War. Because of the Ocean Sunfish's size and bulk, it must consume large amounts of these animals to compensate for their low nutritional value.
The Portuguese Man-of-War is classified as a carnivore. Using its venomous tentacles, a Man o' War traps and paralyzes its prey. Typically, Man o' War feed upon small aquatic organisms, such as fish and plankton.
Commensalism and symbiosis
The Portuguese Man o' War is often found with a variety of marine fish, including shepherd fishMan-of-war fish
The man-of-war fish, Nomeus gronovii, is a driftfish, the only species in the genus Nomeus.Notable for living within the deadly tentacles of the Portuguese man o' war, the man-of-war fish is generally found in open sea or close to the siphonophore Portuguese man o' war, after which it is named...
, clownfish
Clownfish
Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Twenty-eight species are recognized, one in the genus Premnas, while the remaining are in the genus Amphiprion. In the wild they all form symbiotic mutualisms with sea anemones...
and yellow jack
Yellow jack
The yellow jack, Carangoides bartholomaei , is a species of offshore marine fish in the jack family, Carangidae. It is one of only two representatives of its genus present in the Atlantic Ocean, inhabiting waters off the east coast of the Americas from Massachusetts in the north to Brazil in the...
, species that are rarely found elsewhere. The clownfish
Clownfish
Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Twenty-eight species are recognized, one in the genus Premnas, while the remaining are in the genus Amphiprion. In the wild they all form symbiotic mutualisms with sea anemones...
can swim among the tentacles with impunity, possibly due to its mucus that does not trigger the nematocysts. The shepherd fish
Man-of-war fish
The man-of-war fish, Nomeus gronovii, is a driftfish, the only species in the genus Nomeus.Notable for living within the deadly tentacles of the Portuguese man o' war, the man-of-war fish is generally found in open sea or close to the siphonophore Portuguese man o' war, after which it is named...
seems to avoid the larger, stinging tentacles, but feeds on the smaller tentacles beneath the gas bladder. These fish benefit from the shelter from predators provided by the stinging tentacles, and for the Portuguese Man o' War the presence of these species may attract other fish to feed on.
Gallery
External links
- Siphonophores.org General information on siphonophores, including the Portuguese man-of-war
- Poisonous Animals: Blue bottle, Portuguese man-of-war
- National Geographic: Portuguese Man-of-War
- Life In The Fast Lane: Blue bottle