The swordfish is a living torpedo. A report about sword fish How a sword fish hunts
One of the great inhabitants of the depths of the oceans is a predatory swordfish or swordfish (from the Latin "Xiphias gladius").
It belongs to the ray-finned fish from the perch-like order. Belongs to the swordfish family and the swordfish genus. Swordtails are the only species in their genus.
What does a swordfish look like?
As a rule, an individual of this species grows to about 3 meters, but some swordfish grow in length up to 4.5 meters. One fish weighs an average of about 400 kilograms (the largest of the individuals caught had a weight of 537 kilograms).
Females are usually larger than males and have a longer lifespan. Swordtails live for about 10 years.
Outwardly, the predator looks like a sharp deadly weapon, thanks to which the species got its exact name. The bones of the upper jaw, which resemble the blade of a sword, usually reach a length of 1–1.5 meters.
An oblong snout with maxillary bones with a good fat layer is the main weapon of swordfish. They will easily pierce metal with a thickness of 2.5 centimeters or a board with a thickness of 40 centimeters without getting seriously injured.
However, if the "sword" is firmly stuck in the board, then the predator will not be able to get out and will die. The impact force of the swordfish is over 4 tons.
Swordtails have a wide mouth that goes behind the eyes. Young fish grow teeth, but in adulthood they lose them. Very small individuals, when they are still less than 1 meter in length, have spikes on the body. The gill filaments of the swordfish resemble a plate in the form of a grid.
These fish do not have scales, but they have a streamlined, highly developed body and a crescent-shaped tail. This structure allows swordtails to reach speeds of up to 130 kilometers per hour, which makes them faster than the most nimble cheetahs.
In color, individuals of the species in question are usually brown, but cast in dark blue. The sides have bluish metallic tones, and the belly shimmers with silvery hues. The eyes are bright blue. Young predators have stripes on the body, but with age they disappear.
Swordfish lack pelvic fins, but dorsal, pectoral, and lateral fins. However, they are not continuous and are delimited into 2 parts. The front fin on the back is high, black, has a triangular shape and starts from the back of the head. And the rear dorsal fin is located near the tail. The rest of the fins are brownish with lines of black tones.
Most fish maintain their body temperature above the temperature of the water that surrounds them, but swordtails do not have this ability. But they have an organ that warms the blood 15 degrees higher than the temperature in the environment. This blood enters the brain and eyes, which allows swordfish to remain invisible and at the same time find victims at great depths.
Where do swordtails live?
The Pacific, Indian and Atlantic Oceans are where swordfish can be found. That is, they prefer warm waters.
During mass feeding migrations, these predators can also be found in cold waters with a temperature of about 15 degrees, but they need temperature for reproduction. environment about 23 degrees.
Swordfish individuals usually do not swim to the shore, living at depths of 600-800 meters (the maximum can sink to 2800 meters). These predators are solitary, they do not gather in flocks and keep a distance of 10-100 meters from each other.
What do swordtails eat?
This predator feeds on almost any fish and shellfish that it meets on the way. It hunts both small individuals on the surface of the ocean and large fish (for example, sharks) at great depths.
As a rule, the diet of swordfish includes a large number of squid, tuna, mackerel, perch, herring and crustaceans. The predator absorbs its prey entirely or cuts it into pieces with its “sword”.
How do swordtails breed?
In equatorial waters and the western part of the Atlantic Ocean, swordtails can breed all year round. In the waters of the Pacific Ocean, only when the water warms up to 23 degrees, that is, in summer or spring. And the individuals that live in Indian Ocean and the eastern part of the Atlantic, spawning in November-February.
Swordfish are usually fertile individuals, and reach sexual maturity at 5 years. The larger the female, the more eggs she throws. For example, with a weight of approximately 70 kilograms, a fish will bring about 16 million eggs.
The eggs themselves are surrounded by a fatty surface and reach a diameter of up to 1.5 millimeters. They are pelagic, that is, they develop under the surface of the ocean without sinking to the bottom.
Swordfish fry do not have a "sword", but they have many teeth and spikes throughout the body. The fins on the back and sides are still solid. At first, small swordfish feed on zooplankton and live on the surface of the water, never going below 3 meters.
Young swordfish begin to eat small fish when they reach a length of 1 centimeter. Predators grow quickly and already a year have a length of half a meter, and by the age of three they grow up to 1 meter.
The main enemies of the swordsmen
Although swordfish have good weapon to defend and hunt, and they have their enemies.
Among mammals, killer whales prey on swordtails, and among predators, for example, the blue-gray shark. Often adults give a worthy rebuff to opponents, but young and inexperienced swordfish can become easy prey.
However, the most important enemy of the swordfish is man. To catch a predator, the trolling method and the pelagic longline are used. The meat for which swordfish are caught is a real delicacy. It is tasty and does not have small bones and fishy aftertaste. It can be reddish or white - the second is considered more tasty and refined.
5 Fascinating Facts About Swordfish
- Due to its great strength, fast speed and great stamina swordfish is rightfully considered one of the most dangerous predators world waters.
- It is not known why swordtails beat ships and vessels. According to one version, this is due to natural aggression towards everything around, and according to the second, they confuse ships with big fish ocean.
- These predators often prey on whales, although they do not eat their meat.
- Anglers all over the world are actively harvesting swordfish meat, but scientists do not worry about their population, because they have good fecundity.
- The aggressive temper of the swordfish was well described by E. Hemingway in the work "The Old Man and the Sea".
Photo of swordfish
The swordfish is very large marine predator. It belongs to the perch-like order and is considered the only and unique representative swordfish families. Own unusual name this giant got it because of the special shape of the snout in the shape of a sword, which you can see in the photo or video.
Appearance description
Most individuals grow up to 3 meters. However, there were specimens that grew in length over 4.5 meters and weighed 650 kilograms. Distinctive feature The swordfish is an elongated snout that is formed by the premaxilla in the shape of a sword. The mouth is located below, and only young individuals have teeth. The scales of the sword fish are completely absent, the back is dark blue, the sides have a bluish-gray tint, and the belly is painted silver, which can be clearly seen in the photo.
Due to its highly developed muscles and streamlined shape, the swordfish is capable of developing tremendous underwater speed. Some sources say that this fish swims at a speed of over 96 km / h: you can watch its movement on the video. This speed was calculated from the depth of the sword's entry into the wooden boats. There were cases when fish pierced even the sides of boats with swords. But in most cases it was a ridiculous accident, as the fish simply could not change the trajectory, noticing the obstacle.
Distribution and habitats
The swordfish lives in sea waters at depths up to 600 meters. Fish can be found in almost any salt water body, which will be located in tropical and temperate latitudes. The fish begins to feel comfortable at a water temperature of more than 15 degrees. Most often, swordfish can be found far from the coastline.
While searching for food, the fish is able to travel great distances. There were cases when heat-loving fish were noticed in the North Sea. There were isolated cases when she was noticed near Northern Norway. However, for reproduction, the water temperature must be more than 23 degrees Celsius. As a rule, most individuals live in the Atlantic, Pacific and Indian Oceans, Marmara, Mediterranean, Azov and Black Seas.
reproduction
Although people regularly catch swordfish, because of its very tasty meat, which is shown in the photo, this does not reduce the population. This is due to the very high fecundity of females. The older and larger the individual, the large quantity she can spawn. In equatorial latitudes, swordfish spawn throughout the year. In colder waters, it spawns seasonally, when the water temperature warms up above 24 degrees Celsius.
Fry hatched from eggs are not at all like adult fish. They are deprived of their sword, they have teeth, a solid dorsal and anal fin, and also small individuals have scales with small spikes. At first, zooplankton enters the fry's diet, but very soon they begin to eat small fish. As they grow older, the larvae begin to acquire the features of an adult: teeth disappear, scales with spikes, and the dorsal fin begins to separate with a rather large anal gap.
The swordfish is considered an excellent predator, which was created by mother nature for a successful hunt. The presence of excellent reaction and agility, a pointed muzzle and a clear acute vision, aggressive nature and the strongest muscles make this representative of the ichthyofauna a real killing machine, which is dangerous for everyone, in particular for humans. Watch the video, which captures the shooting of the fish sword underwater.
Swordfish, or swordfish (Xiphias gladius) is a representative of a species of ray-finned fish belonging to the perch-like order and the family of swordfish, or Xiphiidae (Xiphiidae). Large-sized fish are able to maintain the temperature of the eyes and brain much higher than the temperature of the environment, which is due to endothermy. active predator has a wide range of food, makes fairly long migrations and is a popular object of sport fishing.
Description of the swordfish
First appearance swordfish received scientific description way back in 1758. Carl Linnaeus on the pages of the tenth volume of the book "The System of Nature" described the representatives of this species, but the binomen has not received changes to this day.
Appearance
The fish has a powerful and elongated, cylindrical in cross section body with a narrowing 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 location of the mouth part of the non-retractable type is characterized by the absence of teeth on the jaws. The eyes are large, and the gill membranes are not attached to the intergill space. Gill rakers are also absent, so the gills themselves are represented by modified plates connected into a single mesh plate.
It is interesting! It should be noted that the larval stage and young swordfish have significant differences from adults in terms of scaly cover and morphology, and gradually occurring in appearance changes are completed only after the fish reaches a meter length.
The pair of dorsal fins is distinguished by a significant gap between the bases. The very first dorsal fin has a short base, starts directly above the posterior region of the head, and contains from 34 to 49 soft-type rays. The second fin is noticeably smaller than the first, shifted far to the caudal part, consisting of 3-6 soft rays. Hard rays are also completely absent inside the pair of anal fins. Pectoral fins swordfish are characterized by a crescent shape, and abdominal ones are absent. The caudal fin is strongly notched and month-shaped.
The back of a swordfish and its top part bodies are dark brown, but given color gradually turns into a light brown shade in the abdominal region. The membranes on all fins are brown or dark brown in varying degrees of intensity. Young individuals are distinguished by the presence of transverse stripes, which completely disappear in the process of 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 marine oceanodromous pelagic fish can reach 600-650 kg.
Character and lifestyle
The swordfish is deservedly considered to be the fastest and most agile swimmer of all currently existing on the planet. sea depth inhabitants. 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 body structure. Thanks to the so-called "sword", the indicators of frontal resistance are noticeably reduced during the movement of fish in a dense water medium. Among other things, adult swordfish have a characteristic torpedo-shaped and streamlined body, completely devoid of scales.
Swordfish, along with its closest relatives, possess gills, which are not only respiratory organs, but also serve as marine life a kind of hydrojet type engine. Through such gills, a continuous water flow is carried out, and its speed is regulated by the process of narrowing or expanding the gill slits.
It is interesting! Swordfish are able to make long voyages, but in calm weather they prefer to rise to the surface of the water, where they swim, exposing their dorsal fin. Periodically, the swordfish picks up speed and jumps out of the water, then noisily falling back.
The body of the swordfish has a temperature that is about 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, which allows it to suddenly develop significant speed in the process of hunting or, if necessary, to 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 perch-like order and the swordfish family, 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 the Arctic latitudes. Large oceanodromous pelagic fish are found in the Atlantic Ocean, in the waters of Newfoundland and Iceland, in the North and mediterranean seas, as well as near 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 among the active opportunistic predators and have a fairly wide range of food. Since all currently existing swordfish are inhabitants of the epi- and mesopelagic zone, they make 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 large or small animals from near-surface waters, as well as bottom fish, cephalopods, and fairly large pelagic fish.
It is interesting! The difference between swordtails and marlin, using their "spear" solely for the purpose of stunning prey, is the defeat of the victim with a "sword". In the stomachs of caught swordfish, there are squids and fish that are literally cut into several pieces or have traces of damage inflicted with the help of a "sword".
The diet of a significant number of swordfish inhabiting the coastal waters of eastern Australia, until some time ago, was characterized by the predominance of cephalopods. To date, the composition of the diet of the swordfish differs in individuals that live in coastal and open waters. In the first case, fish predominate, and in the second, cephalopods.
Reproduction and offspring
Data on the maturation of swordfish are very scarce and very contradictory, which is most likely due to differences in individuals living in different areas. Swordtails spawn in the upper water layers at temperature regime at the level 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 caribbean and in Gulf of Mexico breeding peak occurs from April to September. AT pacific ocean spawning occurs in spring and summer.
Swordtail caviar is pelagic, with a diameter of 1.6-1.8 mm, completely transparent, with 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 the 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 distinguished into separate phases. The hatched larvae have a poorly pigmented body, a relatively short snout, and peculiar spiny scales are scattered all over the body.
It 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”.
With active development and growth, the jaws of the larvae lengthen, but remain equal in length. Further growth processes are accompanied by more rapid development it is the upper jaw, due to which the head of such a fish acquires 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, the 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, only the anterior enlarged part of the dorsal first fin, the second shortened dorsal fin and a pair of anal fins with a clear separation from each other are preserved in the swordfish.
Swordfish today is considered the only representative of the swordfish family. This animal got its name due to the peculiar shape of the upper jaw. Usually, 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 sub tropical waters, sometimes they can be found in the Black and Azov Seas. Individuals appear in moderately warm waters during the period of forage migration. So, at this time, fish can be found in the waters of Iceland, not far from Newfoundland. Animals appear in
The swordfish has an elongated upper jaw, powerful lateral keels on the tail. The body of the animal is devoid of scales. All this in combination allows her to develop enough great speed- per hour up to one hundred and thirty kilometers. The swordfish has no ventral fins, and its tail resembles a crescent in shape. Adult representatives are almost completely missing teeth, but young animals have jaw teeth. They have reticulate plates as gill filaments.
The upper jaw, shaped like a spear, deserves special attention. This part makes up about a third of the entire length of the body. With the help of 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.
A sailboat slave looks like a swordfish. Despite almost the same size and external data, they belong to different families.
The similarity can be seen in the photo.
Swordfish lives in waters with a fairly wide temperature range. During fattening, members of the family are not too demanding on 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 spawn exclusively in tropical waters, the temperature of which is more than twenty-three degrees.
Animals have a fairly high fertility. A small female can lay a lot of eggs - more than fifteen million. From relatively large larvae appear, which are 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, fry have coarse 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 their development, they make do with zooplankton. When their length reaches a centimeter, they move on 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. The adults eat and small fish that inhabits near-surface waters. The diet includes large predators such as tuna. In rare cases, swordfish can even attack a shark.