The ocean is full of mysteries and secrets. The inhabitants of the depths are the most diverse and different from each other. One of the unusual inhabitants is predatory swordfish. Swordfish (Swordsman) refers to the species of ray-finned fish, the order is percussion. This is a fairly large inhabitant who is able to move very quickly.
Origin of view and description
Photo: Sword Fish
For the first time this species was described in 1758 by the Swedish natural scientist and physician - Karl Linnaeus. The work was presented in one of the volumes of the book "System of Nature". The name of this species comes from the Latin "gladius" - "sword", and the name of the genus from lat. "Xiphias" - "a short sword, pointed on both sides." To date, the name of the species has not changed. This is the only representative of the family of Swan.
The name of the predator indicates its unusual appearance: the long overgrowth of the bones of the upper jaw in structure and size resembles a real weapon, like a sword, which is almost one third the length of the fish itself. This jaw is called rostrum. Biologists say that thanks to him, swordfish stuns its prey, breaking into shoals of mackerel and tuna. The fish itself does not suffer from such actions, since at the base of its “sword” there are fat shock absorbers that soften the force of the blow.
Sometimes a swordsman attacks ships. This behavior is not explained in science. Sometimes this is explained by the fact that the swordfish takes the ship for its enemy (for example, a whale).
Interesting fact: In 2015, a swordsman pierced a man who harbored her into the chest. This led to the death of the underwater hunter.
Swordfish is a valuable commercial fish. Its world catches exceed 100 thousand tons per year. Swordsman makes extensive migrations.
Appearance and features
Photo: Sea fish sword
Swordfish is a large inhabitant of the ocean. The size of the body usually reaches 3 meters, and some grow to a length of almost 5 meters. The weight of an adult is from 300 to 550 kg. By its appearance, the predator resembles a powerful deadly weapon (hence the name of the species). The main difference from other inhabitants of the ocean is a long outgrowth of the upper jaw, which resembles a sword. It is 1/3 of the length of the whole body.
The fish has an elongated snout with maxillary claws, and under it is a dense fat layer. It will not be difficult for an inhabitant to pierce, for example, a metal 2-3 cm thick without even getting injured! Swordfish has a fairly wide mouth. Only young fish have teeth. Over time, the predator loses them. In babies (individuals up to 1 m.) On the body there are small spikes. Young predators acquire stripes on the body, which also disappear over time. The swordfish does not have scales, but it has a very developed and streamlined body. The tail has a semi moon shape.
The color of these individuals is most often brown with a dark blue tint. Blue eyes. This inhabitant does not have abdominal fins, but there are dorsal, lateral and pectoral fins, delimited into 2 parts. The high front fin black of triangular shape originates from the occipital part, and the rear fin is located near the tail.
Interesting fact: The structure of the body allows you to reach speeds of up to 130 km / h! Ichthyologists say that such a huge speed to overcome the water column violates all the known laws of physics!
The average life of swordsmen is 10 years. Females live longer than males and are larger in size.
Where does the swordfish live?
Photo: Beautiful fish sword
Swordfish loves a warm climate. Sometimes it swims under the sun and airs the fin, which is located on the dorsal part. Most often, the predator is found in the Atlantic, Indian and Pacific Oceans, that is, it is tropical and subtropical waters, where there is an active time for food.
These individuals have a migration period when the place of residence moves to another water. Usually they swim in temperate latitudes: the Mediterranean, Marmara, Black, and Sea of Azov. In the colder part, they can also be found, for example, they are found in the North Sea. In summer, the fish swims in cold waters, and then returns with a change in temperature.
Favorable water for existence is 12-15 degrees (reproduction occurs at 23 degrees). Fry and caviar survive at 24 degrees. The sword fish lives at a depth of 800 meters, and if necessary can drop to 2800 m. During the day, the sword-bearer prefers spending time in the water column, and at night is near the surface. The average speed of the swordfish is about 34 km per day.
In flocks or schools, the fish is not going to, but prefers to be alone. Pairs are formed only during periods of active reproduction. The distance between residents of this species is from 10 to 100 m from each other. An individual does not inhabit the coast. In the Arctic latitudes, swordfish does not live. Fishermen witness swordfish jumping out of the water. This means that the individual gets rid of parasites that wind up on their body.
What does swordfish eat?
Photo: Sword Fish
Swordfish is an opportunistic predator and powerful hunter. The diet is huge (other fish, shellfish, plankton, etc.). Swordfish fry already have several small teeth and a thin snout. They feed on commonly found plankton and grow rapidly. So there is a gradual transformation into an adult.
In pursuit of his prey, the swordsman develops a speed of up to 140 km / h. Thanks to the near-eye organ, the predator can see and capture its prey in the thickness of the ocean. It is almost impossible to hide from a predator! Based on the fact that the fish plunges into water to a depth of 800 m, and also moves on the surface, between open waters and coastal areas, it feeds on both large and small organisms. In a word, the swordsman eats absolutely everyone who meets in her way. She is able to cope even with a predator (like a shark).
To a greater extent, the diet consists of:
- sea bass;
Sometimes a swordfish, having found a victim, can stun it with a "sword." Researchers have discovered that squids, fish that are chopped in pieces or damaged by a “sword” are found in the stomach of this individual. In addition, the predator is able to swallow the prey as a whole.
Interesting fact: swordfish can even attack whales! Such behavior has not yet been explained by scientists, since this individual does not eat whale meat.
Features of character and lifestyle
Photo: Swordfish swordfish
Swordsman has its own characteristics:
- huge speed of movement;
- special structure of gills;
- unusual body temperature;
- attack on ships (ships).
Swordfish is considered the fastest specimen in the ocean, which carries a weapon in the form of a sharp sword. This characterizes it as a dangerous and predatory fish, which is better not to catch the eye! Fish also has a special structure of gills. They perform not only the function of breathing, but also a jet type engine. For example, with the rapid movement of fish, water passes in an endless stream through the gills and is ejected using them under pressure. At the same time, the swordfish narrows and expands the gills, which helps to control the speed of the water flow.
Another feature is the unique body temperature. It is almost a dozen and a half degrees higher than the temperature of the water in which the fish lives. A special property is that the swordsman has a peri-eyed organ that warms the blood. This allows the fish to be almost undetected in the depths of the ocean, as the blood enters the brain stem and eyes.
Such features allow the swordfish to be constantly in motion and active. She is always ready for a lightning-fast throw and capture of the victim, and also quickly evades her enemies. A swordsman has the habit of attacking boats or large vessels. Since the fish has a huge speed of movement - this gives it great power to strike. A sword breaks through metal plating and thick oak planks. Under such conditions, the fish itself does not receive blows.
But there is another danger for her: sometimes it happens that the sword gets stuck in the bottom of the vessel, and it cannot be pulled out or broken off. Unfortunately, after this the swordsman dies. For fishermen, this is valuable prey.
Social structure and reproduction
Photo: Sea fish sword
Swordfish prefers to hunt and move individually rather than in groups. Each predator acts independently of its neighbors. Only during the breeding season can one observe groupings of pairs. At such times, individuals usually approach the shores for the process of throwing eggs. Favorable temperature of water for reproduction is 24 degrees, but not lower. Caviar reaches large sizes (up to 1.8 mm) and has a significant fat subshell.
Hatched fish have peculiar coarse scales and prickly spikes arranged in a row. The fins are not yet divided, but located completely. Fry initially inhabit the surface of the water, not dropping below 3 meters. Further, with growth, development and change in the activity of predators occurs. The sword grows back when the fish has reached a length of 8 mm, and already with a length of 1 cm the swordsman can prey on fry of other fish. By the first year of life, the predator has a length of up to 60 cm.
The process of transformation of the larva into an adult proceeds smoothly, without drastic changes. A fish 1 meter long acquires all the characteristics of an adult. At 3 years old, most young swordfish move to the border waters of tropical latitudes, where they continue to intensively feed, grow and develop.
Puberty occurs upon reaching a body length of 140-170 cm (this is approximately 5 or 6 years). The fertility of the swordfish is high. The larger the female, the more she spawns. For example, a female weighing 65 kg can reproduce about 15 million eggs.
Natural enemies of swordfish
Photo: Sword Fish
Swordfish has an awesome and formidable look. With her behavior, she is able to scare away many inhabitants of the ocean. Despite this, the swordsman has natural enemies. One of them is killer whale. This mammal will attack swordfish, but adults, thanks to their gigantic physique, give a sharp rebuff to killer whales. Another of the enemies was the mako shark or gray-blue shark. She often hunts young swordsmen who have not yet learned to defend themselves. Adult representatives fight the shark until the last, until the enemy dies from a smashing sword.
The main enemy of swordfish (and all animals and fish) is a man. The fish suffers from fishing in the pelagic tier. There is also sport fishing, where capture occurs by trolling. Catching this fish has been going on since ancient times to obtain delicious meat. It is very tasty and expensive, does not have a "river" aftertaste and small bones.
Depending on how and what the fish ate, the meat may be red, orange (if shrimp prevailed in the diet) or white. The most popular is white fillet, which is considered more refined and of high quality. Scientists are not worried about the activity of obtaining meat from the swordsmen, since they have good fertility.
An important fact: the meat of a swordsman is contraindicated in pregnant women and young children, as it is considered toxic due to the predominance of organometallic cations in it.
Population and species status
Photo: Swordfish fish
Scientists conducted research and calculated that nearly 40% of marine inhabitants are on the verge of depletion. If no attempts are made to reduce the catch, then by 2050 the indicator may approach or even increase by 90%. The problem boils down to the fact that with the disappearance of fish and shellfish, large individuals also die. Fishing is not only official fishing, but also amateur fishing, and, worst of all, poaching.
Currently, there is often news of the illegal fishing of valuable fish - a swordsman. For this purpose, deep-sea nets or special drift nets are used. The well-known Greenpeace organization 10 years ago put the swordsman on the red list of seafood, which are on store shelves in huge volumes, which is a consequence of overfishing.
Swordfish (Swordsman) has a special structure and appearance, which turns it into an enemy or in reliable self-defense. The struggle continues with unlimited fishing for this fish, but so far its population is still large thanks to fertilization. Fish is both a predator and prey for other inhabitants of the ocean (sharks and killer whales), as well as food for humans. It is always worth remembering that the reserves of the planet are in limited quantities. It is necessary not only to consume, but also to protect and protect what surrounds us.