Swordfish is a living torpedo. What does swordfish look like and where does it live? Swordfish description for children

Swordfish, or swordfish (Xiphias gladius) is a representative of a species of ray-finned fish belonging to the order Perciformes and the swordfish family (Xiphiidae). Large fish are able to maintain the temperature of the eyes and brain significantly higher than the ambient temperature, which is due to endothermy. The active predator has a wide range of nutrition, makes fairly long migrations and is a popular object of sport fishing.

Description of swordfish

The appearance of swordfish was first scientifically described back in 1758. Carl Linnaeus, on the pages of the tenth volume of the book “System of Nature,” described representatives of this species, but the binomen has not received changes to this day.

Appearance

The fish has a powerful and elongated body, cylindrical in cross section, tapering towards the tail. The so-called “spear” or “sword”, which is an elongated upper jaw, is formed by the nasal and premaxillary bones, and is also characterized by a noticeable flattening in the dorsoventral direction. The lower-positioned, non-retractable mouth part is distinguished by the absence of teeth on the jaws. The eyes are large in size, and the gill membranes are not attached to the interbranchial space. Gill rakers are also absent, so the gills themselves are represented by modified plates connected into a single mesh plate.

This is interesting! It should be noted that the larval stage and young swordfish have significant differences from adult specimens in scale cover and morphology, and the gradual changes in appearance are completed only after the fish reaches a meter in length.

The pair of dorsal fins is distinguished by a significant gap between the bases. The very first dorsal has a short base, begins immediately above the posterior region of the head and contains from 34 to 49 rays of a soft type. The second fin is noticeably smaller than the first, shifted far towards the tail, consisting of 3-6 soft rays. Inside the pair of anal fins, hard rays are also completely absent. The pectoral fins of the swordfish are sickle-shaped, while the ventral fins are absent. The caudal fin is strongly notched and month-shaped.

The back of the swordfish and its upper body are dark brown in color, but this color gradually turns into a light brown shade in the abdominal region. The membranes on all fins are brown or dark brown in color of varying degrees of intensity. Young individuals are distinguished by the presence of transverse stripes, which completely disappear during the growth and development of the fish. The maximum length of an adult swordfish is 4.5 m, but most often does not exceed three meters. The weight of such ocean-dwelling pelagic fish can reach 600-650 kg.

Character and lifestyle

The swordfish is rightfully considered to be the fastest and most agile swimmer of all the inhabitants currently existing in the deep sea. Such an oceanodromous pelagic fish is quite capable of reaching speeds of up to 120 km/h, which is due to the presence of certain features in the structure of the body. Thanks to the so-called “sword”, drag indicators are noticeably reduced as the fish moves in a dense water environment. Among other things, adult swordfish have a characteristic torpedo-shaped and streamlined body, completely devoid of scales.

Swordfish, along with its closest relatives, have gills, which are not only respiratory organs, but also serve the marine life as a kind of hydrojet type engine. A continuous water flow occurs through such gills, and its speed is regulated by the process of narrowing or widening the gill slits.

This is interesting! Swordfish are capable of long-distance swimming, but in calm weather they prefer to rise to the surface of the water, where they swim with their dorsal fin exposed. Periodically, the swordfish picks up speed and jumps out of the water, immediately falling noisily back.

The body of swordfish has a temperature that is approximately 12-15 o C higher than the temperature regime of ocean water. It is this feature that ensures the high “starting” readiness of the fish, allowing it to unexpectedly develop significant speed during the hunt or, if necessary, evade enemies.

How long do swordfish live?

Female swordfish tend to be noticeably larger than male swordfish and also have a longer lifespan. On average, representatives of the species of ray-finned fish, belonging to the order Perciformes and the family Swordfish, live no more than ten years.

Range, habitats

Swordfish are common in the waters of all the world's seas and oceans, with the exception of Arctic latitudes. Large oceanodromous pelagic fishes are found in Atlantic Ocean, in the waters of Newfoundland and Iceland, in the North and Mediterranean Seas, as well as off the coastal zone of the Azov and Black Seas. Active fishing for swordfish is carried out in the waters of the Pacific, Indian and Atlantic oceans, where the total number of representatives of the swordfish family is now quite high.

Swordfish diet

Swordfish are active opportunistic predators and have a fairly wide food spectrum. Since all swordfish existing today are inhabitants of the epi- and mesopelagic zone, they carry out constant and vertically directed migrations in the water column. Swordfish move from the surface of the water to a depth of eight hundred meters, and are also able to move between open waters and coastal areas. It is this feature that determines the diet of swordfish, which includes animals large or small organisms from near-surface waters, as well as bottom fish, cephalopods and fairly large pelagic fish.

This is interesting! The difference between swordfish and billfish, which use their “spear” solely for the purpose of stunning prey, is the defeat of the victim with the “sword”. In the stomachs of caught swordfish there are squid and fish that are literally cut into several parts or show signs of damage caused by a “sword”.

The diet of a significant number of swordfish inhabiting the coastal waters of eastern Australia was, until some time ago, characterized by a predominance of cephalopods. Today, the composition of the diet of swordfish differs between individuals that live in coastal and open waters. In the first case, fish predominate, and in the second, cephalopods.

Reproduction and offspring

Data regarding the maturation of swordfish are very scarce and very contradictory, which is most likely due to differences in individuals living in different habitats. Swordfish spawn in the upper water layers at a temperature of 23°C and salinity in the range of 33.8-37.4 ‰.

The spawning season of swordfish in the equatorial waters of the World Ocean is observed year-round. In the waters of the Caribbean Sea and the Gulf of Mexico, peak breeding occurs between April and September. In the Pacific Ocean, spawning occurs in the spring and summer.

Swordfish caviar is pelagic, with a diameter ranging from 1.6-1.8 mm, completely transparent, with the presence of a fairly large fat drop. Potential fertility rates are very high. The length of the hatching larva is approximately 0.4 cm. The larval stage of swordfish has a unique shape and undergoes a long metamorphosis. Since such a process is continuous and takes a long period of time, it is not separated into separate phases. The hatched larvae have a weakly pigmented body, a relatively short snout, and peculiar spiny scales scattered throughout the body.

This is interesting! Swordfish are born with a round head, but gradually, in the process of growth and development, the head becomes pointed and becomes very similar to a “sword”.

As they actively develop and grow, the jaws of the larvae lengthen, but remain equal in length. Further growth processes are accompanied by more rapid development of the upper jaw, due to which the head of such a fish takes on the appearance of a “spear” or “sword”. Individuals with a body length of 23 cm have one dorsal fin extending along the body and one anal fin, and the scales are arranged in several rows. Also, such juveniles have a lateral sinuous line, and teeth are located on the jaws.

In the process of further growth, the anterior part of the dorsal fin increases in height. After the body length of the swordfish reaches 50 cm, a second dorsal fin is formed, connected to the first. Scales and teeth, as well as the lateral line, completely disappear only in immature individuals that have reached a meter in length. At this age, swordfish retain only the anterior enlarged part of the dorsal first fin, the second shortened dorsal fin and a pair of anal fins that are clearly separated from each other.

The fantastic speed with which the swordfish (lat. Xiphias gladius) swims is still a mystery to scientists.

The swordfish gets its name from its highly elongated and flattened upper jaw, which has the shape of a pointed sword and accounts for up to a third of the length of the entire fish. The torpedo-shaped body of an adult swordfish is devoid of scales, which contributes to high-speed swimming. The swordfish is a fast and active swimmer, reaching speeds of up to 130 km/h.

At the very end of World War II, the English tanker Barbara sailed through the waters of the Atlantic Ocean. The weather was calm and calm. And suddenly the sailor on watch noticed that a long torpedo was rushing at great speed right into the side of the tanker, leaving behind a foam trail on the surface of the ocean. The sailor raised the alarm, but a few moments later the torpedo had already reached its target, hit the side of the tanker, but... there was no explosion. And the “torpedo” quickly moved away from the ship, turned around and rushed at it again. It turned out that it was a swordfish. During the second attempt to ram the ship, she broke her sword weapon, and she herself got stuck in the hole.

When the aggressive fish was pulled onto the deck, it turned out that the length of its sword exceeded one and a half meters, the length of its body was five meters, and the weight of the live torpedo was 660 kilograms.

When a swordfish rushes along the surface of the water, the tips of its triangular fins protruding above the water leave a foamy trail on the water, similar to the trail of the retractable devices of a submarine or a moving torpedo. And it was not without reason that the watchman of the “Barbara” raised the alarm: the swordfish was misleading even more experienced sailors. During the war in 1942, six Soviet submarines moved from the Pacific Fleet to the Northern Fleet across the Pacific, Atlantic oceans and six seas.
So, in the area of ​​Cocos Island off the coast of Costa Rica, the commander of the S-56 submarine, Captain Lieutenant G.I. Shchedrin, also mistook a swordfish coming towards the boat for the periscope of an enemy submarine and was forced to evade the enemy’s “attack.”

During World War II, one of the American minelayers was patrolling off the Pacific coast of the United States when it was attacked by a swordfish. Her attack caused such serious damage to the wooden-hulled ship that the personnel had difficulty coping with the flow of water through the hole made by the swordfish. The mine in emergency condition was towed to the base.

In general, swordfish are extremely aggressive and unpredictable. What makes swordfish attack ships? Ichthyologists have still not been able to give an exact answer. But in the history of navigation, many cases have been documented when huge swordfish went to ram not only fishing boats or boats, but also ships, and caused such great destruction to their hulls that the ships sank. Therefore, sailors try to stay away from places where sword-like fish accumulate, and even more so, do not launch small floating craft (boats, whaleboats, dinghies, etc.) in these places.

In 1948, a swordfish attacked the American four-masted schooner Elizabeth. The blow of the fish was so strong that it entered the hull of the ship up to the eyes. Having pulled out the sword, the fish went away, and water poured into the hole that had formed, and the crew had to turn on the emergency pumps in order not to drown.

In November 1962, a large swordfish was caught in the net of a Japanese 39-ton schooner fishing for tuna in the Marshall Islands. Trying to escape from the net, the fish broke through the hull of the ship. The crew's attempts to save the schooner were futile and the ship sank.

Already in our time, a swordfish rammed a Japanese trawler, punching such a hole in its bottom that, despite all the efforts of the sailors, the ship sank within a day.

Swordfish attacks are also dangerous for modern ships with metal hulls. So, off the coast of England, a swordfish almost sank the destroyer Leopold, breaking through the 2 cm thick steel plating of the ship in three places. To repair the holes, divers had to be lowered overboard.

The swordfish is so aggressive that it even attacked the American deep-sea vehicle Alvin with three aquanauts off the coast of Spain at a depth of 605 meters, searching for a hydrogen bomb dropped from an American B-52 bomber in July 1967. The aquanauts saw some huge fish through the porthole, and the Alvin shuddered from a powerful blow. The device was urgently raised to the surface along with a fragment of a sword stuck in the groove between the body of the device and the porthole mount. Miraculously, the electrical wiring of the device and the window glass survived; it only cracked and began to leak slightly. The swordfish drove its “weapon” into the groove with such force that it took two hours to remove it from the body.

Attacks on swordfish vessels have been so frequent and have been observed for so long that 120 years ago, the British marine insurance company Lloyd's was forced to introduce a risk clause that took into account "damage to the ship's hull as a result of attack by swordfish." This point was introduced for a reason. In 1856, the captain of the American clipper Dreadnought filed a claim against Lloyd's for insurance compensation for damage to the insured cargo - two hundred tons of tea. The captain claimed that his clipper near the island of Ceylon was attacked by a swordfish, which pierced the copper sheet of the hull and the 8 cm thick pine board of the hull, making a hole 25 cm in size in the hull. The water that penetrated inside the hold naturally spoiled the tea. The company at first did not believe the captain of the clipper, but experts who examined the ship at the dock came to the conclusion that only a swordfish could have made such a smooth, round hole. It was then that the company introduced a clause regarding damage to the ship’s hull as a result of a swordfish attack.

THE SECRET OF SWORDFISH
The first acquaintance with swordfish by humans took place in 1840, when fisherman Figueiro from the island of Madeira caught a hitherto unseen fish on a hook from great depths, which local fishermen immediately named simply and simply - swordfish. It turned out that the meat of the exotic fish has high gastronomic merits, and therefore swordfish became an object of commercial production everywhere. True, its fishing was associated with great risk, for the swordfish turned out to be a creature with an obstinate character and was often the first to attack fishermen and sink their ships.

Swordfish are sword-like fish. This separate and small group also includes marlin, sailfish, spearfish and some other fish. Their distinctive feature is a long and sharp, protruding bone growth of the upper jaw, the so-called rostrum. In swordfish it is flat oval, in marlin and sailfish it is round. The weight of a swordfish reaches 700 kg, marlins have a slightly smaller weight, the length of a swordfish’s sword is about one and a half meters.

An 842-pound swordfish caught by George Garey in 1936 near Tocopilla, Chile.

During an attack, swordfish have been recorded to reach speeds of up to 140 km per hour, almost three times faster than dolphins and sharks. It is this absolutely incredible speed that baffles ichthyologists, physicists and mechanics, in which they still remain. According to all the laws of mechanics and physics, a swordfish cannot develop such a speed in water. Calculations show that to move in water at a speed of about 140 km per hour, a body with an ideally streamlined shape and surface and a length of five meters must have a power of 1500-2000 horsepower.

This power supply is comparable to the power supply of a light aircraft. Moreover, the swordfish develops such power for a long time. It is this paradox of swordfish energy that has long worried the minds of scientists who still do not understand what allows swordfish to set speed records that can be the envy of not only cheetahs, but also birds and even light aircraft.

The first scientist to show interest in the unusual abilities of swordfish was the great Russian mathematician and shipbuilder A. N. Krylov. He had the opportunity to deal with a case when a swordfish attacked a wooden ship and its rostrum pierced right through the side, an oak barrel standing in the hold and, stuck in it, broke at the very base.

Alexey Nikolaevich had already seen traces of swordfish attacks on ships more than once in maritime museums. For example, the maritime museum in Kensington (England) houses an interesting exhibit: a sawn-out piece of planking along with the frame of a sailing ship from the early 19th century. Copper sheet, two-layer pine sheathing and an oak frame 56 cm thick. And all this is strung on a swordfish “skewer”, with its tip sticking out from the inside of the frame.

So this time Krylov decided to check everything with mathematical calculations. It turned out that the speed of the swordfish at the moment of the attack was at least 90 km per hour. Such a speed at that time seemed simply unthinkable, and if it was not questioned by the scientific community, it was only because of the generally recognized world authority of the academician. Later it turned out that a speed of 90 km per hour is far from the limit for swordfish.

Regarding the impact force of a swordfish, Krylov wrote that “the impact force of an average swordfish on the area of ​​the tip of the nose is equal to 15 times the impact force of the heaviest two-handed sledgehammer.” Subsequently, more accurate dynamic calculations showed that the impact force during an attack by even an average (again, only average) swordfish reaches more than four tons.

As for the penetrating ability of the swordfish, Academician V. Shuleikin wrote in his book “Essays on the Physics of the Sea” that the swordfish attacked the whaling ship “Fortune”, breaking through the copper plating, a seven-centimeter board under it, and a thick oak frame thirty centimeters and the bottom of a barrel with blubber that was in the hold.

In a word, the swordfish is not only a dangerous predator, but also an extremely interesting object for bionic and mechanical research, because if scientists were able to uncover its secret, it would be of great service to shipbuilders around the world.

The report about the swordfish will tell you what the swordfish eats, where it lives, and how it lives. The message about the sword fish can be used in preparation for the lesson. The story about the sword fish for children can be expanded.

Report on swordfish

Swordfish, which is also called swordtail is a large predatory sea fish.

Swordfish is quite large, its length is about 3 meters, and some individuals reach a length of 4.55 m. The average weight of swordfish is about 400 kg. Females are larger than males and live longer. The name of this unique fish reflects its unusual appearance. Her nose resembles a sword, the length of which is approximately a third of the entire body (1-1.5 meters).

The unusual nose of the swordfish easily penetrates 2.5 cm thick metal and a 40 cm thick oak board. Dynamic calculations show that the impact force of an average swordfish is more than 4 tons.

The mouth of the swordfish has a lower position, the mouth is wide, extending behind the eyes. Teeth grow exclusively in young fish; mature fish completely lose their teeth. Also, young fish up to 1 meter long have spines on their bodies.

The streamlined body of the fish has no scales and its shape resembles a torpedo. At the end of the caudal peduncle, well-developed crescent-shaped lateral carinae grow on both sides. The tail also has a crescent shape. Thanks to this structure, the speed of a swordfish when attacking can reach 130 km/h.

The dorsal and lateral fins of swordfish are not solid, like those of most fish, but are delimited by a wide gap into 2 parts. The pectoral fins of swordfish are located closer to the lower part of the body. The swordfish does not have pelvic fins.

The surface of the back of the swordfish is dark brown, but shimmers with a dark blue color, the sides are grayish-brown with a blue metallic tint, and the light brown belly shimmers with a silvery color. The fish's eyes are bright blue.

Lifespan of sword fish

On average, swordfish live for about 10-12 years.

Where does swordfish live?

Swordfish is a true marine cosmopolitan that lives in the warm tropical and subtropical waters of the world's oceans: the Atlantic, Indian and Pacific oceans.

Swordfish live in open ocean spaces far from the shore at a depth of about 600-800 meters, descending into the ocean to a maximum depth of 2878 meters. The swordtail is a solitary hunter, and even during mass migrations to feeding areas, predators do not gather in flocks, but remain at a respectful distance, maintaining 10 to 100 m of personal space.

What does swordfish eat?

Swordfish is a dangerous predator. They eat different types of fish and shellfish, and squid.

Reproduction of sword fish

Swordfish breed only in warm water at temperatures above 23 degrees.

Swordfish reaches sexual maturity at 5-6 years of age. A female swordfish weighing about 68 kg can produce an average of 16 million eggs, and particularly fertile individuals spawn up to 29 million eggs.

Egg throwing occurs in the open sea, the eggs are quite large, 1.5-1.8 mm in diameter, surrounded by a large fat capsule. Swordfish eggs are pelagic; they do not sink to the bottom, but remain to develop under the surface of the water.

The swordfish fry that are born are significantly different in appearance from their parents. They don't have a sword yet, but their mouths are full of teeth. The dorsal and anal fins are not yet divided into parts, and the entire body is covered with rows of rough scales with small sharp spines. At first, swordfish fry live at the very surface of the water, not descending to a depth of more than 2-3 m, and feed mainly on zooplankton.

The predatory instinct awakens early, and already at a length of 1 cm, swordfish fry begin to eat small species of fish. Juveniles grow quite quickly, becoming similar to their parents, and by the end of 1 year of their existence, the average size of the fish is 0.5 - 0.6 m, and at the age of 3 years, swordfish grows to 1-1.2 m in length. At three years of age, most young swordfish move to the border waters of tropical latitudes, where they continue to intensively feed, grow and develop.

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Swordfish today is considered the only representative of the swordfish family. This animal received its name due to the peculiar shape of the upper jaw. Typically, an adult swordfish, a photo of which can be easily found on the Internet, can reach a length of more than four meters, and its weight fluctuates around half a ton. Animals live in tropical and subtropical waters, sometimes they can be found in the Black and Azov Seas. Individuals appear in moderately warm waters during the period of feeding migration. So, at this time the fish can be found in the waters of Iceland, not far from Newfoundland. Animals appear in

The swordfish has an elongated upper jaw and powerful lateral keels on the tail. The animal's body is devoid of scales. All this together allows her to develop sufficiently higher speed- per hour up to one hundred thirty kilometers. The swordfish does not have pelvic fins, and its tail resembles a crescent in shape. Adult representatives are almost completely missing teeth, but young animals have jaw teeth. They have mesh plates as gill filaments.

The spear-shaped upper jaw deserves special attention. This part makes up about a third of the entire body length. Using its upper jaw, the swordfish strikes its prey: it cuts it in half. This is evidenced by the bodies of squid and fish found in her stomach.

The sailfish is similar in appearance to a swordfish. Despite almost the same size and external data, they belong to different families.

The similarity can be seen in the photo.

Swordfish live in waters with a fairly wide temperature range. During fattening, representatives of the family are not too demanding of warm waters; they are often found in water areas with a temperature of about twelve degrees. During the spawning period the situation changes dramatically. Swordfish spawns exclusively in tropical waters, the temperature of which is more than twenty-three degrees.

Animals are distinguished by fairly high fertility. A small female can lay quite a lot of eggs - more than fifteen million. From the relatively large ones, larvae emerge, distinguished by a relatively short jaw, and when the larva reaches a length of eight millimeters, it takes the form of a spear. Compared to adults, which have neither teeth nor scales, juveniles have rough scales with small spines, as well as jaw teeth. occurs around the fifth or sixth year of life.

The nutrition of the larvae depends on their age. At the very beginning of development, they make do with zooplankton. When their length reaches a centimeter, they switch to small fish. During the first year of life, fish individuals reach about fifty centimeters. By the third year, their length often becomes more than a meter. Adults also feed on small fish that inhabit near-surface waters. The diet also includes large predators, such as tuna. In fairly rare cases, a swordfish can even attack a shark.