What is poisonous physalia (Portuguese man-of-war)? Jellyfish "Portuguese boat": description and photo Portuguese warship jellyfish

Portuguese boat (lat. Physalia physalis) belong to very primitive, but very interesting invertebrate organisms - siphonophores, close relatives of jellyfish familiar to all of us. This is perhaps one of the most numerous inhabitants of the ocean surface.

They are held on the surface by an air bubble - a pneumatophore, which sometimes has impressive dimensions - up to 15-20 cm. Relatively short digestive organs - gastrozoids hang down from the pneumatophore, and spirally twisted trapping tentacles - dactylozoids go down among their thick fringe. Their dimensions often reach 30 meters, and they can be reduced to 1/70 of their original length.

Physalia tentacles are a very formidable weapon. Woe to the crustaceans or small fish that touch them: thousands of poisoned arrows dig into their body, causing paralysis and quick death. I have repeatedly experienced their aggressive temper on myself - often the backbone of the tuna layer is entangled with tentacles of physalia, which, in the heat of fishing passions, are not always noticed in time. A thin thread fluttering in the wind, like a merciless biting whip, burns an unprotected body.

The physalia are very brightly colored: the sail-pneumatophore casts in blue, violet and purple colors, and the long dactylozoids are ultramarine, and it is very difficult to see them in the water. On the surface of the water, physalia move without expending energy. The obliquely set crest of the pneumatophore plays the role of a rigid sail and forces the physalia to sail at an acute angle to the wind.

The sight of such a sailing flotilla sailing in one direction is impressive. The way they move on the surface has long been compared to the movement of a sailing ship. They got their name "Portuguese boat" in the 15th century after the famous caravels of Henry the Navigator.

Physalia are common in tropical and subtropical waters of all oceans. In the Sea of ​​Japan, they are observed relatively rarely; they are brought here in the summer by the Tsushima Current. They can also be found in the south of the South Kuril region.

Senior Researcher, Laboratory of Ichthyology, IBM FEB RAS, Candidate of Biological Sciences A. S. Sokolovsky.

The bite of a jellyfish is very unpleasant and cruel. Jellyfish are armed with nematocysts. Upon contact with the tentacle, millions of nematocysts penetrate the skin and inject venom. But only the poison of some species causes an adverse reaction in humans.

The effect ranges from mild discomfort to severe pain and death. Most jellyfish stings are not fatal, but box jellyfish (Irukandji jellyfish) such as sea wasps can become lethal, causing anaphylaxis (a form of shock). In the Philippines alone, jellyfish kill between 20 and 40 people a year.

Peculiarities

The Portuguese man-of-war has a close resemblance to a jellyfish, in fact it belongs to the siphonophores. In fact, it is a colony of the smallest individual organisms working in tandem as a "single" organism (sort of like coral reefs).

Their tentacles can grow up to 50 meters long, bigger than a blue whale!

In most cases, the jellyfish sting itself is not fatal, although the venom sometimes interferes with the heart or lungs, and can potentially lead to death.

Most portuguese man-of-war bite deaths are actually caused by swimmers panicking as they drown while trying to swim to shore.

These ocean dwellers cannot move on their own. They swim in large groups where the wind and currents take them.

Dangerous but very beautiful

If you were asked to talk about the most dangerous animals on earth, you would probably start by describing stereotypical killing machines such as lions, tigers, bears (oops!), sharks, crocodiles, alligators, other large animals with terrible teeth and claws.

Because these animals have long been associated with danger and, of course, they should be taken seriously. Nature, however, is complex. Not all hazards are clear.

In fact, for many of the most dangerous animals on earth, you wouldn't even think to be afraid until it's too late.

Claws, razor-sharp teeth are certainly scary, but mother nature has provided some marine life with much less obvious weapons that are also deadly (if not more): poisons and toxins.

There are countless animals that release toxins into their victims in order to incapacitate them.

For some, this is a way to get prey, others use it as a means of self-defense. Either way, the results for the victim are the same - excruciating pain and death.

These animals have several names: Latin and very feminine - "Physalia" and Russian, sounding warlike - "Portuguese warships", often shortened simply to "Portuguese boats". This name itself is mysterious, and given that such a contradictory combination accurately reflects the nature of these creatures, then the story about them can intrigue anyone. So who are these mysterious strangers?

It would be more correct to start the story about physalia with their systematic position. These marine animals belong to the class Hydroids, which means that their relatives are such coelenterates as jellyfish, sea anemones, corals, as well as lesser known porpits and velellas. With jellyfish, Portuguese boats have a similar appearance. The body of the physalis is devoid of any skeletal elements, it is not just soft, but very delicate, translucent, of all kinds of shades of the sea wave. In the guise of a Portuguese boat, two parts can be conditionally distinguished: an oblong bladder up to 30 cm long, very similar to the swimming bladder of fish, and many tentacles hanging in thick strands under it.

Physalia, or Portuguese boat (Physalia physalis).

The bubble, at first glance, seems to be an analogue of the dome of jellyfish, but it is arranged in a fundamentally different way. Unlike the dome of jellyfish, which is open from below and can contract, the bubble of physalia is hermetically closed and filled with air with a high content of carbon dioxide, which is why it is scientifically called a pneumatophore (“air carrier”). The pneumatophore does not allow the Portuguese boat to sink, at the same time, it makes it possible to partially regulate the depth of immersion by changing the concentration of carbon dioxide, and, consequently, the density of the air. From above, the pneumatophore is equipped with a crest, which gives it sailing properties. For all its apparent fragility, the pneumatophore is quite elastic and durable.

The translucent body of physalia is colored in the entire spectrum of blue: from pale blue to deep turquoise. In many individuals, the pneumatophore is pink or magenta-violet above.

But with the underwater part of the physalia, everything is much more complicated. What appears to be part of the body from afar is actually a colony of tiny organisms. And in this respect, Portuguese boats are much closer to colonial coral polyps than to jellyfish, which are solitary animals. The entire population of the colony is divided into identical groups - cormidia, whose members specialize in performing certain functions. Gastrozoids, gonozoids, and nectophores play leading roles in each cormidia.

The intricacies of the tentacles of the Portuguese man-of-war close-up.

Gastrozoids have thin, but unusually long tentacles for such miniature creatures - their length reaches 50 m! The tentacles can contract and carry stinging cells capable of firing venom. They pull the slaughtered prey to the mouth, because the duties of gastrozoids include catching and digesting lunch. And this banquet is being started for the sake of gonozoids, who do not know how to hunt, but are responsible for procreation. Periodically multiplying gonozoids are separated from the mother colony and set off for independent swimming. As truly colonial organisms, they undertake this journey not alone, but in groups that look like a branched tree (it is called a gonodendra). The problem is that gonodendras can't swim. This is where the nectophores, who have not shown themselves for the time being, come to the rescue. Each gonodendra is equipped with one nekotophore, which has a swimming bell like a jellyfish. It shrinks and moves the young colony to the surface of the water, over time it acquires its own pneumatophore and turns into an adult Portuguese boat. In adult physalia, nectophores no longer play a role in locomotion and are again waiting in the wings for the generational change.

The tiny Portuguese boat already has a dome and the beginnings of tentacles.

The movement of adult Portuguese boats is amazing. On the one hand, the fragile and primitive members of the colony are not capable of active movements and any meaningful activity. On the other hand, in life, physalia are rarely washed ashore, which cannot be said about the highly developed dolphins and giant whales, which are often overtaken by such a disaster. The secret of these animals lies in the pneumatophore. It is attached to the trunk of the colony obliquely and motionless - exactly like a taut sail. When the wind hits the side surface of the pneumatophore, the physalia floats, and when it blows into the "bow" or "stern", it remains motionless on the surface of the water, simply drifting. Thus, gradually turning around their own axis, these animals make continuous circular migrations, localized mainly in open ocean waters. For this unsurpassed ability in catching the right wind, physalis were called boats.

Young physalia, in which a full-fledged pneumatophore has not yet formed, but tentacles are already well developed.

It is interesting that among these animals there are born right-handers and left-handers, in which the pneumatophore is deviated to the right or left of the body axis. In practice, this leads to the fact that right-handed and left-handed physalia catch winds of opposite directions, so over time, life literally separates them in different directions. Navigators, finding large concentrations of adult Portuguese ships in the ocean, know for sure that all the "vessels" of this armada will have the same sails. However, there is an element over which the drifting flotilla has no control. These are currents.

Strong tides and storm waves carry the tender physalia ashore and then on the sand you can see a mournful picture of a mass "shipwreck". The seagull decided to feast on the remains of this.

A romantic story about living little boats would be incomplete without revealing the dark side of their nature. By the nature of food, Portuguese warships are predators. The prey of these animals consists mainly of fry, small fish and squid, but gentle creatures use strong poison to kill them. It acts paralytically on prey, and upon contact with human skin leaves burning red scars on it. In high concentrations, the poison penetrates through the skin and causes swelling of the larynx, suffocation, impaired cardiac activity, and in especially severe cases, death. In case of contact with physalia, wash the affected skin area with salt water as soon as possible. It will remove the remaining nematocyst capsules without releasing the poison, and if you wash the skin again with hot water, this will accelerate the breakdown of the toxin that has already entered the skin. Sometimes, after such treatment, it is advised to additionally apply shaving cream to the skin and run a razor over it several times to remove the remaining stinging cells. But in no case should fresh water be used, since nematocysts burst from it, releasing new portions of the poison. It used to be recommended to treat the skin with vinegar, but the results of its application are contradictory and this method has now been abandoned.

Among the tentacles of this physalia, you can see an unfortunate fish.

The main danger of physalia lies in the persistence of their poison and the nematocysts that carry it: even tentacles torn off from the colony and individuals that died a few days ago can burn. This increases the likelihood of a burn when swimming, accidentally touching a boat that has been washed ashore. Every year, up to 30,000 victims of contact with Portuguese warships are recorded in the world. After storms that wash the physalis ashore, some beaches even have to be closed.

Nematocysts of the Indo-Pacific physalia (Physalia utriculus), inside which are coiled stinging filaments. When the poison capsule is damaged, they shoot, delivering the toxin directly to the victim's tissue.

The Portuguese ships themselves are also not spared from troubles. They fearlessly feed on poison-resistant webbed octopuses and moonfish, as well as loggerhead turtles, whose mouth cavity is impenetrable to stinging tentacles. Especially insidious are the yantin snails and the nudibranch mollusk glaucus (glaucus). They use the physalium pneumatophore as shelter and home, and instead of gratitude, they gradually eat their host. Not so vicious are the small nomeus fish, which constantly keep under the pneumatophores of the boats. Although they pinch off pieces of tentacles, they do not eat them to the end, finding reliable protection from large fish in their plexus. Good neighbors of physalia are yellow jacks, often swimming in the thick of "flotillas".

Two glaucuses (Glaucus atlanticus) encroach on the life of this Portuguese boat.

Two types of physalia are known in the world: the Portuguese warship itself, which lives in the Atlantic Ocean, and the Indo-Pacific physalia, whose name eloquently indicates that it can be found in the Indian and Pacific oceans. The Indo-Pacific physalia differs from its counterpart in its smaller size (pneumatophore length up to 16 cm), one long tentacle and less toxicity: not a single lethal outcome has been recorded with its participation.

And this physalia was lucky. She calmly swims in the waters of the Gulf of Mexico, surrounded by good neighbors - Nomeus fish (Nomeus gronovii).

portuguese boat or physalia(lat. Physalia physalis) - similar to a floating colony of polyps, forming a single organism. Its tentacles contain a large number of stinging cells that are dangerous to humans.

Description

Externally, the Portuguese boat (lat. Physalia physalis) resembles a jellyfish, only instead of a dome near the physalia there is a large bubble filled with ordinary air with a large amount of carbon monoxide, which keeps it on the surface of the water. This bubble outwardly resembles the sail of an 18th-century Portuguese ship, which is why the animal was given the name - Portuguese boat. Another important difference between the physalia and the jellyfish is that, unlike the jellyfish, it is not one multicellular organism, but a colonial organism consisting of specialized individual protozoa of the same species, called polyps or zooids. These polyps are connected to each other and are physiologically integrated in such a way that they cannot survive separately and therefore must exist together and act as one animal. In what follows, for simplicity, we will often refer to the Portuguese man-of-war as a single organism, but you must remember that this is not entirely true in general.

The sail of the Portuguese boat is bilaterally symmetrical, with tentacles on one side only. Translucent. Blue or purple color prevails, sometimes pink or lilac is found. The sail reaches 30 cm in length and can rise 15 cm above the water. It is equipped with a “siphon”, with which the physalia can release air and briefly go under water. This mechanism is used as a defensive reaction when attacked. But the ship does not have many natural enemies. Only a few can prey on them - the mouth of turtles is very hard, and the poison does not get inside the tissues.

Usually the length of the tentacles does not exceed half a meter. But it is not uncommon for them to grow up to 10 m in length. Cases of the discovery of Portuguese ships with 30-meter tentacles have been documented! These tentacles constantly scour underwater in search of medium-sized fish and small planktonic animals. The ship pulls the stung prey to the dome, where there are digestive polyps, the so-called gastrozoids, which envelop the victim and digest with the help of special secreting enzymes.

Habitat

Found in the Atlantic, Indian and Pacific Oceans. Always stays close to the surface of the water. Since it has no means of transportation, it follows the currents and the wind. Usually found in warm tropical and subtropical waters, but can easily be introduced into colder northern waters. There are known cases of detection of physalia off the coast of Canada and Great Britain. They are rarely seen alone, and if one Portuguese man-of-war has been sighted, there are almost certainly others nearby.

At high tide it can be close to the shore. Strong wind and waves are able to take the Portuguese boat to land. Once on land for some time (up to a day) it is able to sting. You can often find news about the closure of entire beaches, when after storms the coast is strewn with dangerous animals.

The record for the number of victims among people affected by the Portuguese boat is held by Australia. Every year, especially in summer, up to 10,000 cases of burns (not fatal) are recorded here. It is especially common off the eastern coast of the continent.

physalia poison

During a burn with the tentacles of a Portuguese boat, a person experiences very severe pain. Red scars remain at the site of the bite, which do not subside for several days. The pain disappears within 1-3 hours, depending on the age of the person and the individual tolerance of the poison. The main danger of a bite is that the poison can penetrate the lymph nodes and cause an allergic reaction, including swelling of the larynx, blockage of the airways, heart failure. Sometimes there is fever and shock, in rare cases - death.

Medical intervention is required with a large number of burns, difficulty breathing and pain that does not stop for more than 3 hours after the bite. Treatment begins with washing the wounds with a 3-5% solution of vinegar (ordinary fresh water destroys cells with poison, increasing pain) - this removes stinging cells that have not yet “worked”. Modern research on the venom of Portuguese boats, however, does not recommend the use of vinegar to treat burns, as in some cases this only aggravates the symptoms.

Symbiosis

The Portuguese boat swims surrounded by some types of fish that are not susceptible to its poison - juvenile military fish, kulihu (coolihoo) and "homeless" clown fish. The latter can move freely inside the dangerous tentacles of the physalia - because of the fish mucus, the stinging cells do not work. Other fish stay near the sail, where there are not many stinging cells.

It is believed that in this way small fish avoid other predatory fish. But such a symbiosis is very useful for the Portuguese boat - small fish attract other careless fish that it preys on.

Video

portuguese boat

Portuguese boat washed up on the beach

The Portuguese boat is not just a beautiful creation of nature. This is a real killer jellyfish that floats on the surface of the water with a transparent bubble filled with gas.

Initially, Portuguese boats could only be found in the waters of the Gulf Stream, as well as in the tropics of the Indian and Pacific Oceans. But since 1989, this flotilla has also drifted into the Mediterranean. Scientists believe that the main reasons for their resettlement were global warming and the disappearance of food due to the large volumes of fish caught.

The Portuguese boat fully justifies its name, which it received back in the 15th century in honor of the flotilla of Henry the Navigator. Its upper part, which is a large transparent bubble 15-20 cm long, is very similar to the stern of a ship. The boat moves only thanks to the wind or the flow of water. Another part of it is hidden under water - poisonous tentacles. Their length can reach 30 meters!

They are equipped with stinging cells, which, like small harpoons, pierce prey and inject poison, which is also dangerous for humans. After contact with the tentacles, severe burns remain on the skin. To relieve pain and destroy the poison, ordinary 3% -5% vinegar helps.

Physalia is especially dangerous for children, the elderly and people with an increased allergic reaction. A fatal case has been reported. In the spring of this year, policeman Igor Kuznetsov died from a jellyfish bite, who ran into her in Egypt during a vacation. He was taken to Moscow by a special flight of the Ministry of Emergency Situations, but Russian doctors failed to pull him out of a coma. Beauty is sometimes dangerous, deadly.

For small fish and crustaceans, meeting with her guarantees a quick death. But there is one fish from the perch order, which is not susceptible to physalia poison. The boat and this fish have developed a wonderful strategy of mutual assistance: the fish serves as a bait for future victims of the physalia, and itself feeds on the remains of prey and the dead ends of the jellyfish tentacles. This is such a wonderful tandem.

But still, the Portuguese boat can also become someone's dinner. The big-headed sea turtle and