More than 300 million people in the world use the GPS system, with the help of which a traveler can determine his coordinates, and a pilot can land a plane in a zone with zero visibility. Over the next decade, the capabilities of the global positioning system will expand significantly.

The capabilities of the global positioning system will become much wider in the next 10 years. The user will be able to determine their coordinates with an accuracy of up to a meter. The capabilities of the GPS system will be expanded through modernization, implying: the introduction of additional signal channels on the satellite, increasing the signal power and improving its correction system, the use of directional antennas, as well as integration with television and telephone cellular networks.

Its new capabilities will primarily be used by the military, for whom it was created. US Navy aircraft will be able to land on the deck of an aircraft carrier in complete darkness. The system will be able to track the location of aircraft throughout the flight. In the near future, GPS will help control the movement of road transport, ensuring road safety; the improved system can be used in the electric power industry, telecommunications, mining, cartography and even in agriculture. In addition, any traveler will be able to use GPS throughout the globe.

The sky limits

The creation of a global positioning system began in the United States in 1978 with the launch of the first Navstar satellite. At that time, the Department of Defense decided to help 40 thousand American military personnel learn to determine their coordinates on land, in water and in the air. Only in the 80s. Cartographers and geophysicists have had access to satellite signals, and civilians have been using the system since the early 1990s, when there were 24 GPS satellites in orbit. Today, about 30 million people use GPS navigation, thanks to which ship captains, car drivers and adventure enthusiasts determine their coordinates. About 200 thousand receivers are sold in stores every month. They sold $3.5 billion worldwide in 2003, and marketing firm Frost@Sallivan predicts annual figures could rise to $10 billion from 2010. (Figures do not include revenue from businesses operating in the industry. ) More than 50% of equipment is purchased by private individuals, 40% by commercial entities, and only 8% by the military.

America is not alone in deploying space-based navigation systems. During the Cold War, Russia deployed Glonass satellites into space orbit. In the near future, this industry will develop rapidly and both cars and mobile phones will be equipped with GPS receivers. The European Galileo project will soon start, which could redistribute the satellite navigation market.

By purchasing a GPS receiver that costs $100, a person can expect a deviation of 5–10 m. Military devices can determine location with an accuracy of up to 5 m. If the GPS receiver receives a signal from a ground station and corrects the data accordingly, its accuracy increases to 0.5 m.

Information rain from space

To understand what awaits us in the future, let's look at what we have today. Satellites transmit two types of signals. One of them carries information about the location of the satellite and the time of signal transmission. It is received by fixed ground stations, processed and sent to a satellite, which transmits it to all users of the system. The second signal is the code necessary to determine the time of signal transmission. The creators of the system call it pseudo-random noise.

It takes time for a signal to travel a distance of 20 thousand km. If the user can, using his receiver, which contains the code, determine the time of its departure, then it will not be difficult to record the time of its passage and, by multiplying the received data by the speed of propagation, calculate the distance to the satellite.

If you install a clock in the GPS successor, then, having received the distance from three satellites, the user will be able to determine the latitude, longitude and altitude of his location. The signal coming from the satellites resembles three spheres intersecting at different times at different points. For a user on Earth, there is only one moment of their contact in a given period of time. For more consistent signal synchronization, the satellites are equipped with atomic clocks that provide accuracy up to one part in a billion. With most GPS receivers, they can be off by one or more seconds per day. It can be calculated that an error of just one second will change the distance from the satellite to the user by 300 thousand km. Engineers call the process of measuring the distance between a satellite and a user pseudo-measurement. The fact is that the error is also present in the signals from four satellites, as a result of which we get four equations with four unknowns.

Modern GPS receivers are able to take into account the Doppler effect if measurements are taken while moving. When the receiver moves in the direction of wave propagation, its length becomes longer, and when moving in the opposite direction, it becomes shorter. Each satellite resembles a high-speed train. If it moves towards you, then its whistle becomes louder as it approaches, and if it moves away, the signal loses power. Taking this effect into account, the speed of the GPS receiver can be obtained. This method of measuring speed is very accurate.

Thus, GPS receivers determine three coordinates and three velocity vectors, and also synchronize time through the network. At the same time, the receivers themselves do not transmit signals on the air. Cell phones will soon be equipped with GPS, which will lead to an increase in price of the latter by only $5.

Overcoming the ionosphere

GPS satellites transmit a signal with a classic sine wave shape at a regular radio frequency. Now two signals are transmitted at microwave frequencies - L-1, L-2. Channel L-1 is available to everyone. It is believed that it is intended for civilian users, although the military does not forget about it. Channel L-2 is intended for military personnel. Civilian users receive this channel on their GPS receivers, but due to the fact that they do not have access to the PRN code, a positioning error occurs. Only expensive receivers allow civilian users to operate in the L-2 band. Therefore, most of them receive the L-1 signal, which allows accurate determination of coordinates from 5 to 10 m.

Difficulties in signal reception are caused mainly by the fact that radio waves on their path overcome the Earth's ionosphere, which is a plasma cloud formed by the Solar wind. Its boundaries extend from 70 to 1300 km above the Earth's surface, and when passing through the ionosphere, radio signals are weakened and distorted. At night, when the ionosphere is at rest, the signal transmission delay is 1 m, and during the day, when plasma activity is high, it is more than 10 m.

In order to minimize the influence of the ionosphere, differentiated D-GPS is used. In this scheme, two receivers are used: one is mobile, and the second is located at a point with known coordinates. The data coming from these GPS is compared and processed, after which the readings of the mobile receiver are adjusted. The closer they are, the more accurately the coordinates are determined.

Strong and directional signals

Beginning in 2005, satellites will transmit additional signals that will help eliminate interference from the ionosphere. Two signals will be added to the military L-1 and L-2 and one to the civilian L-1, and the existing signals will not undergo any changes. The next stage of system improvement will begin in 2008. The satellites will transmit another civilian signal, L-5, which will be 5 times more powerful than now. The dual signal will minimize the influence of the ionosphere. Future GPS receivers will be able to compare the distortion of two signals, making the necessary adjustments to the calculations.

Operators using D-GPS receivers will also benefit. Recall that the accuracy of the D-GPS system decreases as the distance between the fixed receiver and the mobile GPS increases. This is due to the fact that the receivers receive signals from satellites that have passed through different layers of the ionosphere. When working with two signals, mobile GPS is able to estimate the influence of the ionosphere, and data from a fixed receiver will help minimize other errors, which can range from 30 to 50 cm.

To obtain positioning accuracy within centimeters or even millimeters, users can use D-GPS receivers. Their modern models, having communication with a stationary station via a radio channel, transmit information about their location and receive corrected data. The wavelength at which the signal is transmitted from the satellite is 19 cm. The receiver can measure the time it takes to receive the signal with an accuracy of 1%. In absolute terms, this value will be several millimeters.

To make more accurate measurements, the receiver must identify the signal wave from the satellite. Modern GPS compares signals from satellites using L-1 and L-2 channels. In the GPS system, the wavelengths differ by 85 cm, which allows measurements with an accuracy of 8 mm. The reliability of such a measurement system is hundreds of times greater than that of systems working with PRN codes. Their limit is 50 cm. D-GPS receivers working with one L-1 channel provide measurement accuracy of up to 19 cm. Expensive GPS models have the ability to increase measurement accuracy by comparing the frequencies of signals received via L-1 and L-2 channels. With the beginning of transmission of additional signals from satellites, the accuracy and reliability of GPS receivers will significantly increase. Civilian users will have access to the open portion of the L-2 channel and the new L-5 channel. In the future, GPS will be able to compare three pairs of channels (L-1 with L-2, L-2 with L-5, L-2 with L-5L).

Flights with GPS

What other opportunities will open up for GPS users? The US Federal Aviation Administration is developing new rules for flying using the GPS system. Many aircraft are already equipped with such receivers, but their use is limited. The new equipment will allow landing in zero visibility. However, this will require that, firstly, in any situation, the pilot takes into account that instrument readings do not always correspond to the actual location of the aircraft, and in emergency cases, make adjustments to the flight mode. (During landing, the deviation from the given trajectory should not exceed 10 m.) Secondly, aviation systems must have a very high degree of reliability.

Representatives of the US Federal Aviation Administration proposed two systems based on D-GPS technology. The ground part of the complex includes transmitting and receiving antennas connected to the control center. In 2003, a network of WAAS ground stations appeared, which allows real-time correction of the coordinates of all GPS users. (Engineers in Europe, China, Japan, India, Australia and Brazil are working on similar systems.) In case of an error, WAAS makes a correction to the D-GPS user within 7 seconds. Thanks to this, during landing approach, the pilot can guide the aircraft to an altitude of 100 m. In the airport area, the crew switches to piloting mode using ground navigation equipment.

Over time, LAAS navigation systems operating in the shortwave range will be able to provide zero visibility landings using the L-5 channel. The US Navy is developing a JPALS precision aircraft guidance and landing system for aircraft carriers, which is based on the principle of a D-GPS system operating on L-1 and L-2 channels. When approaching and landing, a naval aviation pilot must control the distance to the deck of an aircraft carrier with an accuracy of 1 m so that a special hook on the aircraft body can engage the brake rope. Testing of the JPALS system will begin in 2006.

Scientists and engineers are already working on creating a third-generation GPS system. The launch of new satellites will take place no earlier than 2012. Through the use of satellite communications and the installation of more powerful computing systems on them, the capabilities of the system will be significantly expanded.

Since the secret air base, better known as Area 51, was created on the southern shore of the dry salt lake Groom Lake, many futuristic US Air Force aircraft have been tested there, looking like alien ships from outer space.

Stealth F-117 Nighthawk, SR-71 Blackbird, stealth UAV RQ-170 and others. The portal engadget.com has published a selection of top-secret aircraft that can easily be confused with a UFO.

A-12 "Oxcart"

This high-altitude reconnaissance aircraft was developed specifically for the CIA. The construction of the aircraft was carried out by a secret branch of the Lockheed Corporation - Skunk works. The project was headed by the talented engineer Clarence Johnson, who also supervised the construction of the test facility at Groom Lake.

The A-12 was supposed to fly faster and higher than other aircraft in order to be out of reach of Soviet air defense missiles and fighters. The A-12 squadron was never subordinate to the US Air Force; all missions of these aircraft were led by the US CIA branch specializing in the USSR and Cuba.

The Oxcart remained in service for five years (from 1963 to 1968), then was replaced by the more advanced SR-71 Blackbird. However, the aircraft's existence remained secret until the mid-1990s.

SR-71 Blackbird

This unique aircraft was capable of reaching speeds of up to Mach 3.2 and rising to an altitude of 25.9 km. The SR 71 did not need to evade enemy missiles - it simply outran them.

Despite ending service in the late 1990s, the Blackbird still retains its status as the fastest and highest altitude aircraft. He holds the absolute speed record among manned aircraft with ramjet engines - 3,529.56 km/h.

D-21

The Lockheed D-21 was one of the few aircraft capable of outpacing the SR-71 Blackbird. The US Air Force used it for high-altitude reconnaissance flights. This drone was launched using the M-12 aircraft (A-12 Oxcart variant).

The D-21 could reach speeds of more than M=3.6 at an altitude of more than 30 km, and the flight range was about 2000 kilometers.

This UAV was disposable; after a reconnaissance flight, it dropped containers with film and self-destructed. The D-21 program lasted only two years between 1969 and 1971. The reason for its termination was the high cost of the UAV - $5 million, given that the device was disposable. It was much cheaper to use reconnaissance satellites.

F-117 Nighthawk

If there is any aircraft based on technology borrowed from aliens, it is certainly the F-117 Nighthawk, the world's first stealth fighter (as the Americans themselves classified it).

Although in fact it is a tactical strike aircraft that was never intended to perform fighter missions. The first invisible flight took place on June 18, 1981.

The special aerodynamic shape of the fighter and the use of composite materials greatly reduce the visibility of the night hawk. The F-117's radar cross-section is only 0.001 square meters.

Only very trained pilots who had flown at least 1,000 hours were allowed at the controls of the Nighthawk, which is about three to five years at the controls for a fighter pilot.

A total of 64 aircraft were built, seven of which were lost due to pilot or computer errors.

Tacit Blue

The Tacit Blue stealth aircraft, nicknamed "the whale", has never been used in combat. It was created as a platform for testing the latest stealth technologies. Work on the stealth began in 1978. All the advanced technologies at that time were invested into the aircraft.

It was assumed that the Stealth, invisible to radar, could be used for surveillance from low altitudes, transmitting all the necessary information directly from the battlefield.

During his short service he managed to fly 250 hours before he was retired. "Whale" achieved all its goals, and its program became one of the most successful in the history of the US Air Force. The technologies developed on Tacit Blue were subsequently successfully used on other machines.

General information about this exotic vehicle was only made public on May 22, 1996, when the vehicle became an exhibit at the United States Air Force Museum in Ohio (USAF Museum).

RQ-170 Sentinel

Very little is known about this unmanned stealth reconnaissance aircraft. It began to be used approximately in 2007. The US Air Force and CIA used it for reconnaissance in Pakistan and Iran. The RQ-170 Sentinel was able to detect terrorist No. 1 Osama bin Laden.

Probably the only reason why information about Sentinel became available was the crash of such a UAV in Iran in 2011, then the Iranians showed this intact aircraft in a news release. The US government asked Tehran to give them the drone to no avail.

B-2 Spirit

The B-2 Spirit is a long-range strategic stealth bomber capable of delivering nuclear weapons to any point on the planet, remaining invisible to the enemy, at least until he notices the atomic mushroom.

The B-2 is capable of crossing the Pacific Ocean twice without landing and is equipped with the most advanced aviation technology.

The stealth bomber first took to the skies on July 17, 1989. This is the most expensive aircraft in the history of aviation, its cost is two billion and one million dollars in 1997 prices (then its military service began).

The B-2 Spirit is highly automated, so the crew consists of only two pilots. And, despite its unusual and fragile appearance, the stealth bomber has a significant margin of safety and is capable of making a safe landing in a side wind blowing at a speed of 40 m/s.

Lockheed U-2 Dragon Lady

The U-2 is the oldest surveillance aircraft used by the United States Air Force, along with the B-52 Stratofortress bomber. Dragon Lady has been in use for over 50 years. (began his service in 1957).

This aircraft is capable of tracking the enemy from an altitude of 21.3 km in almost any weather conditions.

The design of the aircraft required a special take-off and climb mode, since at low altitudes at high speed the aircraft would simply fall apart, and at altitude a high speed is needed to maintain lift.

The high-altitude reconnaissance aircraft was only partially pressurized. Therefore, in order to avoid decompression sickness (with a sharp decrease in atmospheric pressure in the pilot’s cabin, nitrogen dissolved in the blood and tissues of the body begins to be released into the blood in the form of bubbles and destroy cell walls, as well as block blood flow), the pilots used the technique of active oxygen saturation, starting to breathe this gas an hour before the flight. Thanks to this, it was possible to slightly reduce the nitrogen content in the blood.

Sturgeon is a real delicacy from which you can prepare many delicious dishes! Find out interesting recipes and use them.

Some useful information

Sturgeon belongs to the sturgeon family and is found in the basins of many seas, such as the Caspian, Azov and Black. Also, these aquatic inhabitants can be found in freshwater bodies of water, for example, in large rivers: the Volga, Ural, Kama. It is difficult to confuse the sturgeon with other representatives, because it has pronounced external characteristics, such as needle-shaped processes running along the ridge, as well as a rounded and flattened nasal part of the head, called the snout.

How is sturgeon useful? This fish is highly valued in cooking, and for good reason, because it contains protein, omega-3 and omega-6 polyunsaturated fatty acids, phosphorus, vitamins D, E and A, as well as other nutrients. The calorie content of 100 grams of product is about 110-130 calories.

Regular consumption of sturgeon will help strengthen hair, nails and bones, increase brain activity, ensure proper muscle function, stimulate the formation of new healthy cells, and improve skin condition.

The cost of 1 kilogram of fresh sturgeon varies from 600-700 rubles to 1-1.5 thousand, depending on the region.

How to make the right choice?

Sturgeon is sold in stores and official markets in frozen, chilled and fresh form. It is better to purchase fresh or chilled fish, but it is not available in all regions. When purchasing, you should pay attention to the pulp: it should be quite elastic and have a pleasant pink-beige tint. There cannot be any damage, dents or stains on the surface. The smell is characteristic of fish, but fresh, not putrid.

Sturgeon preparation

How to clean sturgeon? Its preparation is not as simple as pre-processing other fish, which is due to some features of the body structure. To make the dish tasty and, most importantly, safe, proceed in stages:

1. First, wash the sturgeon well in cool water, then pour boiling water over it: this will remove mucus from the surface.
2. Next, use a sharp knife to carefully cut off the needle-like growths running along the back.
3. Then you need to cut the carcass. To do this, rip open the fish's belly and carefully remove all the contents from it. It is important to be careful not to damage the gall bladder, otherwise the pulp will spoil and become rancid.
4. Now you need to remove the so-called vizig - a vertebral chord, which can be poisonous without proper treatment. To do this, make an incision at the base of the tail down to the bone, trim the vertebra and begin to twist the tail, as it were. When a white-transparent vein appears, pull it: it should be easily removed from the ridge.
5. Next, scald the carcass with boiling water or place in hot water for a couple of minutes. Having made an incision along the ridge, you can remove the skin, starting from the tail and moving towards the head.

Sturgeon dishes

How to prepare dishes from such a delicious fish as sturgeon at home? We invite you to consider interesting recipes.

Baked

Delicious sturgeon can be cooked in the oven. For this you will need:

• 1400-1500 g sturgeon fillet or approximately two kilogram carcass;
• three large onions;
• 250-300 g mayonnaise;
• vegetable oil;
• dill;
• ground pepper (preferably black);
• salt.

Preparation:

1. The sturgeon carcass should be cut and cut into fairly thin steaks. If you use fillet, then it is cut into pieces about one and a half centimeters thick.
2. Peel the onion, cut into half rings or rings.
3. After washing, dry the dill and chop it.
4. Take a baking dish or baking sheet, grease its walls and bottom generously with vegetable oil.
5. Place a layer of onion half rings or rings on the bottom, place sliced ​​sturgeon on them in a thin layer, sprinkle it with salt, chopped dill and pepper, and brush with mayonnaise.
6. Next, lay the ingredients in layers, not forgetting to salt, sprinkle with dill and pepper the sturgeon. The last one should be mayonnaise; it forms an appetizing crust on the surface of the dish and prevents burning.
7. Place the baking sheet in an oven preheated to 190 degrees for about an hour. To make the dish more juicy, you can cover the pan with a lid or wrap it in foil.

Shashlik

You can cook aromatic sturgeon kebab on the grill or coals. You will need the following ingredients:

• 1.5 kg sturgeon;
• 2 large onions;
• 2 bell peppers;
• 2 tomatoes;
• 2/3 glass of white semi-sweet or dry wine;
• a fifth or a fourth of a glass of olive or vegetable oil;
• half a lemon;
• ground pepper;
• salt.

Instructions:

1. Cut the sturgeon into medium-sized cubes. Immerse them in a marinade, which is a mixture of vegetable oil, pepper, lemon juice, salt and white wine. Leave the fish to marinate for a couple of hours.
2. Prepare the vegetables. Cut the tomatoes into slices, onions and bell peppers into fairly large rings. Season all this with salt and pepper if desired.
3. Place vegetables and fish on skewers or skewers.
4. Next, cook the shish kebab on the coals or grill until a crust appears.

Sturgeon in sauce

Try making juicy and flavorful sturgeon. To do this you will need the following ingredients:

• 1 kg sturgeon fillet;
• half a stick of butter;
• two eggs;
• half a glass of sour cream;
• two tablespoons of flour;
• a small amount of broth (preferably fish);
• breadcrumbs;
• dill;
• pepper;
• salt.

Process description:

1. Sturgeon should be cut into portions. Next, rub them with salt and pepper and leave for a while. Break the eggs into a bowl and whisk them.
2. Heat the butter in a frying pan. Dip the fish pieces first in flour, then in the egg mixture, and then in breadcrumbs. Fry the sturgeon on each side until golden brown.
3. Next, place all the fried pieces in a fireproof container, having previously greased it with oil.
4. Prepare a sauce from the remaining oil in the pan. To do this, bring it to a boil again, then pour in the broth. When the mixture boils, reduce the heat to low and add sour cream, as well as chopped dill, pepper and salt.
5. Pour the prepared sauce over the sturgeon. Place the container, uncovered, in an oven preheated to 170 degrees for fifteen minutes.
6. Ready!

Now you can prepare several interesting and delicious dishes from sturgeon and please your family or guests.

The common name for red caviar is granular salmon caviar. It is obtained from chum salmon, chinook salmon, trout, sockeye salmon, coho salmon, pink salmon - salmon fish. Black, accordingly, is obtained from fish of the sturgeon family: beluga, stellate sturgeon, sterlet and, directly, sturgeon. Each of these fish has caviar that differs in both taste and external parameters. In addition, it has different nutritional properties.

Undoubtedly, caviar is one of the calling cards of Russia. There was always a lot of it: black, red, even yellow and pink. They ate caviar with spoons, spread it on bread, and added it to various dishes. This is not only a tasty delicacy, but also very useful, since it contains a huge amount of microelements and vitamins necessary for humans.

Which is better is a controversial, even philosophical question. To decide, it is advisable to try each one. But most gourmets are still inclined to believe that red caviar has the most optimal taste qualities in chum salmon and pink salmon.

Chum and Chinook salmon caviar has the largest eggs - 5-7 mm. Next in decrease are the eggs of coho salmon, pink salmon, and sockeye salmon - 3-5 mm. The smallest eggs of trout are 2-3 mm.

Red caviar also varies in color: deep scarlet caviar of sockeye salmon, bright orange of pink salmon, chum salmon caviar is orange with red splashes.

The most delicate in taste is chum salmon caviar. It has large grains of a bright orange, reddish hue. Rich in protein. For these properties she was nicknamed “royal”. Chum salmon caviar has a distinct taste and is one of the best delicacies.

Pink salmon caviar is considered classic salmon caviar, and it is no less good. It is most common, has medium-sized grains of light orange color. Its taste is universal, very rich, with a subtle spicy note of bitterness. The aroma is delicate.

Sockeye salmon caviar has the brightest taste. Its grains are bright red, small, the taste is sharp and slightly bitter, and has a pronounced aroma. The aftertaste is most intense. Sockeye salmon caviar is very rich in beneficial properties.

Coho salmon eggs are small, the same size as sockeye salmon. In appearance, coho salmon and sockeye salmon caviar can be easily confused, the difference is in taste - the latter is bitter. Coho salmon caviar does not have such a bright, pronounced taste. Unlike other salmon caviar, it has a rich red color.

The “queen” of black granular caviar can undoubtedly be called beluga caviar. In terms of taste and nutritional value, it is unrivaled. It also has no equal in price - it is the most valuable delicacy among all varieties of sturgeon caviar. It can be distinguished by the size of the eggs: they are large, up to 3.5 mm in diameter. The color of beluga caviar is silver or dark gray. The taste is mild.

Sturgeon caviar is slightly lighter and smaller than its more expensive competitor, and has eggs with a yellow or brown tint. The size of the eggs is about 2.5 mm. The taste is more intense. In terms of taste and beneficial qualities, sturgeon caviar is in no way inferior to beluga caviar, but at the same time cheaper than the latter.

The most “democratic” price of black caviar is stellate sturgeon. It has small, about a millimeter in diameter, black eggs. In general, it is denser and more elastic than beluga.

There is a misconception that sturgeon caviar should be almost blue-black. In fact, everything is exactly the opposite. Lighter colors are more valuable. The shade of ripe eggs varies from silver-black to brown-gray. The size of the eggs also affects the price of sturgeon caviar. Rarer caviar has a larger grain, and therefore costs more. The quality of caviar is also indicated by its appearance. The eggs must be whole and uniform.

The dog-toothed snapper is one of the largest of all snappers. He was nicknamed this because of his 4 protruding front teeth. Found in coastal areas from the Gulf of California to Panama, rarely to Peru. Lives in moderate depths among reefs and caves.

Dogtooth snapper - fishing season all year round

Getting to know the fish

First, it’s worth understanding the general concept of snappers. Snapper is a fish belonging to the reef perch family. This is an extremely large family containing many species that are similar in appearance and habits. The most basic species can be considered: red snapper and dog-toothed snapper. The red snapper is the most commonly encountered fish, and the dogtooth is interesting to us for its individuality and gigantic size.

Often all snappers are summarized under the same name, snapper. This fish got its name, snapper, because of its habits during hunting. It happens that individuals of this species, waiting for their prey, lie on the bottom. And when a fish swims past them, at the right moment they unexpectedly and sharply snap their large jaw (snap - English. click) and the prey ends up in the mouth.

Often all representatives of this family with a red body color are called red snapper fish. But this opinion is erroneous and with a more detailed approach, many differences are revealed.

So, our main character is the dog-toothed snapper. This is one of the largest representatives of the entire family. It gets its name from the four sharp teeth protruding from the upper and lower jaws, which are similar to the fangs of a dog.

Distribution area

Dogtooth snapper - distributed in the warm waters of the Pacific Ocean, ranging from the Gulf of California to Panama. This fish can rarely be found off the coast of Peru. It prefers to stay in relatively shallow areas, near coastal areas and exits to the shallows. For shelters, it always chooses areas among reefs, caves, underwater rocks and other shelters. It feeds there too. Sometimes, if there is a large amount of food, it can gather in small flocks and hunt collectively.

Appearance

Snepper is a bright and noticeable fish. It is quite difficult to confuse it with other underwater representatives. As juveniles, the dog-toothed snapper is covered in light dots on a dark purple body, but as it grows, its body color changes to a dark maroon. The back is always darker than the sides, and the belly may have a white tint.

The body is of regular shape - slab-like with streamlined lines, but laterally compressed. Thanks to this, the snapper moves easily and freely across reef shelters. This fish is distinguished by a very large mouth, and, accordingly, a large head in relation to the body. All fins have a color similar to the body color. The bases of both the dorsal and anal fins are covered with scales. The dorsal fin consists of two parts, separated by a small notch. One part is formed by prickly rays, and the second is soft and not prominent. There are about ten such rays in both halves. To remove the spiny fin during sudden movements, there is a special notch on the back.

Four fangs in front and many smaller, sharp teeth cover the front of the jaws. The edges of the gill covers also have very sharp ends. So, having caught a snapper, you should take it in your hands quite carefully.

Features of hunting and nutrition

Legitimately considered a reef fish and spending most of its life in them, the snapper is a fish that hunts in corals and cover. This is a nocturnal predator that can see perfectly in the dark and easily catches its victims. But snapper is also successfully caught by anglers during the day. You can meet him under rock grottoes, in reefs and even sometimes in mangroves. In addition to fish, the main food items for this predator are mollusks and all kinds of crustaceans. Having a large mouth, snappers often attack fish that are even larger than themselves. They have no problems with this - strong jaws and sharp teeth will not allow even such prey to escape.

Snapper fishing

The fishing season for these fish is year-round. There are many ways to catch it. Everything will depend on the preferences of the fisherman and the specific location of this fish. Trolling, spinning, jigging, and vertical jig fishing can be successfully used to catch snapper.

World record according to IGFA: dog-toothed snapper - 56.5 kilograms.

Below you can see the gallery: snapper fish photo.