Arapaima is the fish monster of the Amazon. The length of her body sometimes reaches 2.5 meters, and the weight exceeds 2 centners. This aquatic predator has long attracted the attention of scientists, since such dimensions are not typical.Therefore, in recent years, a lot of efforts have been made to study all the features of the arapaima's life.
Guest from the distant past
Arapaima was first noticed by European scientists at the beginning of the 19th century. Then she was described as a gigantic monster that lives in the basin.However, only recently have scientists been able to fully study all the features of this fish. It turns out that arapaima is a guest from the far past, or, to be more precise, a fossil species. Scientists were prompted to this conclusion by its morphology, which is very different from everything that we are accustomed to today.
Let's start with the fact that arapaima is a lungfish. This means that it can use ambient air as its main source of oxygen. Recall that many fish are deprived of this opportunity, which makes our predator even more unique. In addition, if she did not have such "lungs", she would have died out a long time ago. Indeed, with its gigantic size, the Amazon simply could not provide the fish with the required amount of oxygen.
Giant arapaima: description
The main feature of this fish is its size. On average, adults reach 2 meters in length, but there are many cases when fishermen caught much larger representatives of this species. So, to date, the record is held by the arapaima, the length of which has reached 4.5 meters. Moreover, the weight of an adult fish ranges from 180-220 kilograms.
If we talk about appearance, then arapaima is a fish with a long body, slightly compressed at the sides. In its shape, it looks more like a pike, though much larger in size. The dorsal and anal fins are located at the back of the fish, forming a kind of solid tail. Another important attribute is its large scales. Together they form a clear mesh pattern that is clearly visible even in muddy water.
As for color, nature has awarded arapaima with a light olive shade. In addition, in the light, its scales shimmer with copper, and sometimes even red tones. This can be seen especially well near the belly and tail of the fish. But it also happens that the entire body of a predator is replete with scarlet. That is why the Indians called this fish "piraruku", which means "red fish".
Area
Arapaima is a fish that lives only in South America. True, today it can be found in other regions of the planet, but private breeders brought it there. Consequently, the Amazon Basin is the only place where the Piraruku can survive naturally. If we consider the exact coordinates, then large populations of the species are found in the waters belonging to Peru, Brazil and Guyana.
By the way, earlier this species of fish also inhabited but due to climate change it completely died out. The findings of paleontologists prove that the last arapaims lived here during the Miocene, that is, 5-10 million years ago.
Habitat
Arapaima is a giant fish, so it prefers deep waters. Swampy areas overgrown with algae and shrubs are ideal for her. Here she can find herself not only a full-fledged refuge, but also access to rich sources of food: schools of other fish, molluscs and even amphibians.
Due to its large size, it reacts sharply to changes in water temperature. This is due to the fact that it needs warmth for normal metabolism. Therefore, she tries to avoid cool reservoirs and those parts of the river where cold springs gush. But she tolerates the heat calmly, as evidenced by numerous records of scientists.
Nutrition
Arapaima is a predator fish. At the same time, given its size, one can easily guess that almost any inhabitant of the Amazon River can become its victim. It primarily preys on other fish and invertebrates that are rich in proteins. Also, arapaima does not disdain carrion and eats up what the piranhas did not manage to destroy.
In addition, despite its gigantic proportions, the piraruku is capable of developing serious speed in pursuit of its prey. But most of all, scientists are struck by the fact that arapaima can jump out of the water and catch gape prey. For example, in a jump, she is able to grab a bird or a lizard sitting peacefully on a branch.
Features of behavior
The Amazon fish - arapaima - does not like to waste energy on unnecessary movements. Therefore, at a time when she is not hunting, the predator calmly basks in the sun. If the water in the river is very muddy, then it sticks out its muzzle to the surface and loudly clicks its mouth, swallowing warm air into the "lungs". Fortunately, she can afford such a rest, since she does not have so many natural enemies.
The curious thing is that even piranhas do not touch her. The reason for this is the strong scales of the arapaima, which serves as a reliable armor for it, protecting it from the sharp teeth of a bloodthirsty predator. Therefore, the piraruku does not even pay attention to the fact that such a formidable neighbor lives next to her. The only enemies for arapaima today are alligators and humans, while it was the latter that put this species on the brink of extinction.
Reproduction
Individuals of this species become ready for reproduction only in the fifth year of their life. During the spawning period, fish look for shallow places with a clean sandy bottom. Here they will be able to dig a nest-hole for themselves, where they will then lay their eggs. This event takes place in late April - early May, when the water reaches the most optimal temperature.
At the same time, the parents do not leave the nest until the moment when all the fry hatch. Fortunately, this happens quickly, after 2-3 days "babies" of arapaima are born. After that, they obediently follow their father, who feeds them all this time. To do this, he has special glands located near the eyes. It is they who secrete a special enzyme that serves as a food source for the fry for the next 7-10 days.
Piraruku and the man
Today arapaima is a fish that requires close attention of conservation organizations. Its numbers have dropped dramatically over the past two centuries, prompting scientists to sound the alarm. This was caused by uncontrolled fishing by the local population. And if in the old days the Indians used only harpoons and homemade nets, then with the arrival of the Europeans they learned to use more "fruitful" methods of catching the river giant.
Fortunately, the Brazilian authorities have established a strict moratorium on the capture of arapaima. Now you can hunt for it only once a year, at a specially designated time for this. At the same time, fishermen must initially obtain a license from the authorities, otherwise they will face severe punishment. True, many natives still violate this prohibition, since by selling one fish, they can receive an amount equal to their monthly salary.
One of the most unusual and mysterious fish, first mentioned in the scientific literature only in 1822, truly striking in its size and value of fish meat, is arapaima living in freshwater reservoirs of a tropical climate.
Features of arapaima and its habitat
Giant arapaima, or piraruku, is found most often in the fresh waters of the Amazon. This species became known even to the Guiana and Brazilian Indians and got its name due to the red-orange color of the meat and bright red spots on the scales ("piraruku" - red fish).
The habitat depends on the climate and environmental conditions in which it lives. In the rainy season, they live in the depths of rivers, in a drought they easily burrow into cool sand and silt, they can easily survive even in swampy areas.
Arapaima fish, is one of the most gigantic in the world. According to some official sources, the weight of some individuals can freely reach two centners, and its length sometimes exceeds two meters.
One of the main features of an individual is the extraordinary strength of ribbed scales, it is 10 times stronger than bones and it is problematic to break through it, it is comparable in strength to a shell. It was this fact that allowed the Piraruka to successfully adapt to living next to.
The popularity of this species of fish in their habitats is due not only to its large size, but also to the fact that it is hardly possible to meet an adult in the wild.
For centuries, this fish was considered the main food of the Amazonian tribes. It was its large size and its ability to rise too often to the surface of the water and even jump out of it in search of prey that became destructive - it was easily taken out of the water with the help of nets and harpoons.
Unusual arapaima body structure allows this fish to successfully hunt: the streamlined shape of the body and tail, conveniently located fins allow you to react to the approach of prey with lightning speed and grab it. Currently, the population of Piraruka gigantea has been reduced, and fishing for arapaima is prohibited.
The nature and lifestyle of arapaima
Arapaima fish- the largest aquatic predator, lives in the fresh waters of the Amazon, where a civilized person appears very rarely: in the forests of Brazil, Peru, Guyana. It feeds not only on medium and small fish, but also does not hesitate to profit from birds and carrion in the dry season. The body, riddled with small blood vessels located close to the fish scales, allows hunting on the very surface of the water.
The peculiarity of the structure of the swim bladder (ovoid) and a narrow body help to easily survive drought, adapt to unfavorable environmental conditions, and experience a lack of oxygen.
Due to the extremely scarce oxygen content in the waters of the Amazon, arapaima is forced to float to its surface every 10-20 minutes in order to swallow air noisily. This cannot be called an aquarium, but today it is bred in captivity. Of course, it will not reach large sizes and body weight, but a little more than half a meter can be obtained with ease.
Artificial fish farming, although troublesome, is widespread everywhere: in Latin America, Europe and Asia. They can be found in large aquariums, zoos, artificial reservoirs, adapted for fish farming.
Piraruku is settled separately from other species (to avoid eating them), or with other large predatory fish. In conditions of nurseries, arapaima can live for about 10-12 years, in captivity.
Arapaima fish nutrition
Giant arapaima is a carnivorous species and feeds exclusively on meat. An adult piraruka, under favorable conditions, is selective in the choice of food, as a rule, its diet includes small and medium-sized fish, sometimes birds and medium-sized animals sitting on branches or descending to drink water.
Young animals are more voracious, during the period of active growth they devour everything that comes their way: larvae, fish, carrion, invertebrates, small ones, and vertebrates.
Reproduction and life expectancy of arapaima
Outwardly, the male at a young age is not much different from the female arapaima. However, in the period of puberty and readiness for spawning, the body of the male, overgrown with gills and fins, is several times darker and brighter than that of the female.
Whether a female is ready to reproduce offspring can be judged by her body length and age: she must be at least 5 years old and not shorter than one and a half meters. In the hot, arid climate of the Amazon, spawning occurs in late February - early March.
Usually, during this period, the female begins to equip herself a place where she will later lay eggs. The female piraruka most often chooses for these purposes on the sandy bottom, where there is practically no current, and the depth is not great.
With her long, agile body, the female pulls out a deep hole (approximately 50-80 cm deep), where she lays large eggs. As soon as the rainy season begins, the eggs that have already been laid before burst, and fry emerge from them.
It is noteworthy that arapaima as most freshwater fish do, it does not abandon the hatched fry, but looks after them for another three months. Moreover, the male himself remains with the female, and it is he who makes sure that the eggs are not eaten by predators.
The role of the female after laying eggs is reduced to protecting the territory around the nest; she continuously patrols the area around at a distance of 15 meters from the nest. A special white substance found on the male's head (just above the eyes) becomes food for the young.
This food is very nutritious, and within a week after the birth of the fry begin to feed on "adult" food and disperse, or rather blur, in every direction. Young growth does not grow quickly, on average, the total monthly increase in growth is no more than 5 cm, and in weight no more than 100 grams.
Thus, despite its rather unattractive appearance, arapaima attracts the attention of aquarists and fishing enthusiasts. This fact is connected with the fact that the predator is capable of reaching truly gigantic proportions, and this is not given to all freshwater fish.
It is enough to look only once at the appearance of a piraruka to forever remember exactly how this type of fish looks. This is an opportunist, it is this trait that allowed her, known even in the days of the Brazilian and Guiana Indians, to survive to this day.
In aquarium conditions to breed arapaima quite problematic due to the fact that she needs too large aquariums with a volume of more than a thousand liters, constant water filtration and a specially maintained temperature of at least 23 degrees with a hardness of no more than 10.
The giant arapaima is one of the largest and least studied fish in the world. Those descriptions of fish that are found in the literature are borrowed mainly from the unreliable stories of travelers.
It is even strange how little has been done so far to deepen our knowledge of the biology and behavior of the arapaima. For years, it has been mercilessly fished both in the Peruvian and Brazilian parts of the Amazon, and in its many tributaries. At the same time, no one cared about studying it and did not think about preserving it. The schools of fish seemed inexhaustible. And only when the number of fish began to decrease noticeably, there was interest in it.
Arapaima is one of the largest freshwater fish in the world. Representatives of this species live in the Amazon basin in Brazil, Guyana and Peru. Adults reach 2.5 m in length and weigh up to 200 kg. The uniqueness of arapaima is the ability to breathe air. Due to its archaic morphology, the fish is considered a living fossil. In Brazil, fishing is only allowed once a year. Initially, the fish was harvested with harpoons when it rose to breathe on the surface.
Today it is caught mainly with nets. Let's take a closer look at this ...
Photo 2. 
Photo: View of the Amazon River from the window of the Cessna 208 amphibious aircraft that flew photographer Bruno Kelly from Manaus to the village of Medio Jurua, Carahuari municipality, Amazonas, Brazil, September 3, 2012.
REUTERS / Bruno Kelly
In Brazil, giant fish were settled in ponds in the hope that they would take root there. In eastern Peru, in the jungles of the province of Loreto, certain areas of rivers and a number of lakes have been left as a reserve fund. It is allowed to fish here only under the license of the Ministry of Agriculture.
Arapaima is found throughout the Amazon basin. To the east, it is found in two areas separated by the black and acidic waters of the Rio Negru. In Rio Negro, arapaima is not found, but the river, apparently, is not an insurmountable barrier for fish. Otherwise, one would have to assume the existence of two species of fish, which have different origins and live north and south of this river.
The western area of distribution of arapaima is probably Rio Moro-na, to the east of it Rio Pastasa and Lake Rimachi, where a huge number of fish are found. It is the second protected reservoir in Peru for breeding and observation of arapaima.
An adult arapaima is painted very picturesquely: its back color changes from bluish-black to metallic green, belly - from cream to greenish-white, sides and tail are silvery-gray. Each of its huge scales shimmers with all sorts of shades of red (in Brazil, the fish is called piraruku, which means red fish).
Photo 3. 
Swaying in time with the movements of the fishermen, a small canoe floated on the mirror-like surface of the Amazon. Suddenly the water at the bow of the boat began to swirl in a whirlpool, the mouth of a giant fish stuck out, exhaling air with a whistle. The fishermen looked dumbfounded at the monster, two human height, covered with a scaly shell. And the giant splashed a blood-red tail - and disappeared into the depths ...
Tell such a Russian fisherman, he will immediately be laughed at. Who is not familiar with fishing tales: either a giant fish will fall off the hook, or a local Nessie will be seen. But on the Amazon, meeting a giant is a reality.
Arapaima is one of the largest freshwater fish. There were specimens 4.5 m long! Now you will not find such people. Since 1978, the record of the Rio Negro River (Brazil) has been held, where arapaima was caught with a data of 2.48 m - 147 kg (the price of a kilogram of tender and tasty meat, almost without bones, far exceeds the monthly income of Amazonian fishermen. can be seen in antique shops).
Photo 4. 
This strange creature looks like a representative of the dinosaur era. Yes, it is so: a living fossil has not changed in 135 million years. The tropical Goliath has adapted to the swampy swamps of the Amazon basin: the bladder attached to the esophagus acts like a lung, arapaima protrudes out of the water every 10-15 minutes. She kind of "patrols" the Amazon basin, captures small fish in her mouth and grinds them with a bony, rough tongue (the locals use it as sandpaper).
Photo 5. 
These giants live in the freshwater bodies of South America, in particular in the eastern and western parts of the Amazon basin (in the Rio Moron, Rio Pastasa and Lake Rimachi rivers). A huge amount of arapaima is found in these places. In the Amazon itself, there are not so many of these fish, tk. she prefers quiet streams with a weak current and a lot of vegetation. A body of water with indented banks and a large number of floating plants is an ideal place for her to live and exist.
Photo 6. 
According to local residents, this fish can reach 4 meters in length and weigh about 200 kilograms. But arapaima is a valuable commercial fish, so now there are practically no such huge specimens in nature. Nowadays, specimens of no more than 2-2.5 meters are most often found. Still, giants can be found, for example, in special aquariums or reserves.
Photo 7. 
Previously, arapaima was caught in large quantities and did not think about its population. Now, when the stocks of these fish have significantly decreased, in some countries of South America, for example, in eastern Peru, areas of rivers and lakes have been identified, which are strictly protected and fishing in these places is allowed only under a license from the Ministry of Agriculture. And even then in limited quantities.
Photo 8. 
An adult can reach 3-4 meters. The powerful body of the fish is covered with large scales that shimmer in various shades of red. This is especially noticeable in its tail part. For this, the locals gave the fish another name - piraruku, which translates as "red fish". The fish themselves are of different colors - from "metallic green" to bluish-black.
Photo 9. 
Her respiratory system is quite unusual. The pharynx and swim bladder of fish are covered with lung tissue, which allows the fish to breathe normal air. This adaptation has developed due to the low oxygen content in the waters of these freshwater rivers. Thanks to this, arapaima can easily survive drought.
Photo 10. 
The manner of breathing of this fish cannot be confused with anyone. When they rise to the surface for a breath of fresh air, then small eddies begin to form on the water surface, and then the fish itself appears in this place with a huge open mouth. All this action lasts just a couple of seconds. It lets out the "old" air and takes a new sip, the mouth closes abruptly and the fish goes deep. Adults breathe like this every 10-15 minutes, young ones - a little more often.
Photo 11. 
On the head of these fish there are special glands that secrete special mucus. But what it is for, you will find out a little later.
Photo 12. 
These giants feed on bottom fish, sometimes they can eat small animals, such as birds. In juveniles, the main dish is freshwater shrimp.
Photo 13. 
The breeding season for Piraruku is in November. But they begin to create pairs already in August-September. These giants are very caring parents, especially males. Here I immediately remembered how the male "sea dragons" take care of their offspring. These fish do not lag behind them. The male digs a shallow hole about 50 centimeters in diameter near the coast. The female lays eggs in it. Then, during the entire period of development and maturation of eggs, the male is next to the clutch. He guards eggs and swims near the "nest", while females drive away fish swimming nearby.
Photo 14. 
After a week, fry are born. The male is still next to them. Or maybe they are with him? Young animals keep in a dense flock near its head, and even to breathe they rise together. But how does a male manage to discipline his kids like that? There is a secret. Remember, I mentioned about special glands on the head of adults. So, the mucus that is secreted by these glands contains a stable substance that lures the fry. This is what makes them stick together. But after 2.5-3 months, when the young grows up a little, these flocks disintegrate. The bond between parents and children is weakening.
Photo 38. 
Once the meat of these monsters was the staple food of the peoples of the Amazon. Since the end of the 1960s, arapaimas have disappeared completely in many rivers: after all, only large fish were killed with a harpoon, while nets allowed catching babies. The government has banned the sale of arapaime less than one and a half meters long, but the taste, which only trout and salmon can rival, pushes people to break the law. It is promising to breed arapaim in artificial pools with heated water: they grow as much as five times faster than carp!
Photo 15. 
However, here is the opinion of K. X. Lüling:
The literature of past years greatly exaggerates the size of the arapaima. These exaggerations, to a certain extent, began with the descriptions of R. Shom-burk in the book "Fish of British Guiana", written after a trip to Guiana in 1836. Shoem-burk writes that fish can be 14 feet (ft = 0.305 meters) in length and weigh up to 400 pounds (pounds = 0.454 kilograms). However, this information was obtained by the author from the second hand - from the words of the local population - he personally did not have evidence to confirm such data. In a well-known book on the fish of the world, McCormick questions the veracity of these stories. After analyzing all the available and more or less reliable information, he concludes that the arapaim species never exceed 9 feet in length - a solid enough size for freshwater fish.
From my own experience, I was convinced of the correctness of McCormick. The animals we caught in Rio Pacai averaged 6 feet in length. The largest fish turned out to be a female 7 feet long and weighing 300 pounds. Obviously, the illustration from the old editions of Brehm's Animal Life, depicting an Indian sitting on the back of a pyraruku, 12 to 15 feet long, should be considered sheer fantasy.
The distribution of arapaima in certain areas of the river depends, apparently, more on the vegetation growing there than on the nature of the water itself. Fish requires a heavily indented coast with a wide strip of coastal floating plants, which, intertwining, form floating meadows.
For this reason alone, fast-flowing rivers like the Amazon are not suitable for the existence of arapaima. The bottom of the Amazon always remains smooth and uniform, so there are few floating plants, the same as there are, usually entangled among shrubs and hanging branches.
On Rio Pakai, we found arapaim in backwaters, where, in addition to floating meadows of aquatic grasses, floating mimosas and hyacinths grew. Elsewhere, these species may have been replaced by floating ferns, victoria-regia, and a few others. The giant fish is invisible between the plants.
Perhaps not surprisingly, arapaimas prefer to breathe air rather than oxygen from the swampy waters in which they live.
Photo 16. 
The manner of inhaling air is very characteristic of the arapaima. When a large fish approaches the surface, a whirlpool first forms on the water surface. Then the fish itself suddenly appears with its mouth open. It quickly releases air with a clicking sound, inhales fresh air and immediately plunges into the depths.
By the whirlpool formed on the surface of the water, fishermen hunting for arapaima determine where to throw the harpoon. They throw their heavy weapon right into the middle of the whirlpool and in most cases they miss the target. But the fact is that giant fish often live in small reservoirs, 60-140 meters long, and eddies are constantly formed here, and therefore, the likelihood of the harpoon getting into the animal increases. Adults appear on the surface every 10-15 minutes, young ones more often.
Having reached a certain size, arapaima goes to the fish table, specializing mainly in bottom shell fish. In the stomachs of arapaim, the spiky needles of the pectoral fins of these fish are most often found.
In Rio Pakai, the living conditions for arapaim are obviously the most favorable. The fish that live here reach maturity within four to five years. By this time they have reached about six feet in length and weigh between 80 and 100 pounds. It is believed (although not proven) that some, and possibly all, adults reproduce twice a year.
Once I was lucky enough to observe a pair of arapaimas preparing for spawning. Everything happened in the clear and still waters of the quiet bay of Rio Pakai. The behavior of arapaimas during spawning and their further care for the offspring is a truly amazing sight.
Photo 17. 
In all likelihood, fish dig out the spawning hole in the soft clay bottom with their mouths. In the quiet bay where we were observing, the fish chose a spawning site just five feet below the surface. For several days, the male was within this place, and the female stayed 10-15 meters from him almost all the time.
The young growth, having hatched from the eggs, remains in the burrow for about seven days. A male is constantly next to them, either circling over the hole, or perching on the side. After that, the fry rise to the surface, relentlessly following the male and keeping in a dense flock near his head. Under the supervision of the father, the whole flock at once floats to the surface to inhale the air-Spirit.
At the age of seven to eight days, the fry begin to feed on plankton. Observing the fish through the still waters of our quiet bay, we did not notice that the fish were raising young growth, that is, they would take the fish in their mouths at the moment of danger. There was also no indication that the larvae were feeding on the substance released from the plate-like gills located on the heads of the parents. The local population makes a clear mistake in assuming that the young are feeding on their parent's "milk".
In November 1959, I was able to count 11 schools of juvenile fish in a lake of about 160 acres (an acre is equal to about 0.4 hectares). They swam close to the shore and parallel to it. The flocks seemed to be avoiding the wind. This is probably due to the fact that the waves generated by the wind make it difficult to inhale air from the surface of the water.
We decided to see what would happen to the school of fish if it suddenly lost its parents, and we caught them. The orphaned fish, having lost contact with their parents, thereby obviously lost contact with each other. The tight flock began to disintegrate and eventually dispersed. After a while, we noticed that juveniles in other flocks were significantly different from each other in their size. Such a large contrast could hardly be explained by the fact that the same generation of fish developed differently. Apparently other arapaims adopted the orphans. Expanding the swimming circle after the death of their parents, the orphaned fish spontaneously mixed with neighboring groups.
Photo 18. 
On the head of the arapaima there are glands of a very interesting structure. On the outside, they have a series of small, tongue-like protrusions, at the ends of which, with the help of a magnifying glass, you can distinguish the smallest holes. Through these holes, mucus formed in the glands is released.
The secretion of these glands is not used as food, although it would seem that this is the simplest and most obvious explanation for its purpose. It performs much more important functions. Here's an example. When we pulled the male out of the water, the flock accompanying him remained for a long time in the very place from which he disappeared. And one more: a flock of juveniles gathers around a gauze pad, previously soaked in the male's secretions. It follows from both examples that the male secretes a relatively stable substance that keeps the whole group together.
At the age of two and a half - three and a half months, flocks of young animals begin to disintegrate. By this time, the bond between parents and children is weakening.
Photo 19. 
Residents of the village of Medio Jurua display a gutted pirate on Lake Manaria, Carauari municipality, Amazonas state, Brazil, September 3, 2012. Piraruku is the largest freshwater fish in South America.
REUTERS / Bruno Kelly
Photo 20. 
Photo 21. 
Photo 22. 
Photo 23. 
Photo 24. 
Photo 25. 
Photo 26. 
While fishing, a caiman was caught in the net of the inhabitants of the village of Medio Jurua. Villagers set up a piraruca fishing on Lake Manaria, Carahuari municipality, Amazonas state, Brazil, September 3, 2012. Piraruku is the largest freshwater fish in South America.
REUTERS / Bruno Kelly
Photo 27. 
Photo 28. 
Photo 29. 
Photo 30. 
Photo 31. 
Photo 32. 
Photo 33. 
Photo 34. 
Photo 35. 
Photo 36. 
These giants live in the freshwater bodies of South America, in particular in the eastern and western parts of the Amazon basin (in the Rio Moron, Rio Pastasa and Lake Rimachi rivers). A huge amount of arapaima is found in these places. In the Amazon itself, there are not so many of these fish, tk. she prefers quiet streams with a weak current and a lot of vegetation. A body of water with indented banks and a large number of floating plants is an ideal place for her to live and exist.
Quiet waters and a sea of vegetation are ideal conditions for these fish to live. 
According to local residents, this fish can reach 4 meters in length and weigh about 200 kilograms. But arapaima is a valuable commercial fish, so now there are practically no such huge specimens in nature. Nowadays, specimens of no more than 2-2.5 meters are most often found. Still, giants can be found, for example, in special aquariums or reserves.
Giants can be found in captivity 
And here is one of them. What are its dimensions - I have no idea. Previously, arapaima was caught in large quantities and did not think about its population. Now, when the stocks of these fish have significantly decreased, in some countries of South America, for example, in eastern Peru, areas of rivers and lakes have been identified, which are strictly protected and fishing in these places is allowed only under a license from the Ministry of Agriculture. And even then in limited quantities.
The catch of these fish is strictly controlled. 
Happy faces of fishermen 
An adult can reach 3-4 meters. The powerful body of the fish is covered with large scales that shimmer in various shades of red. This is especially noticeable in its tail part. For this, the locals gave the fish another name - piraruku, which translates as "red fish". The fish themselves are of different colors - from "metallic green" to bluish-black.
"Red fish" 
Large scales 
Her respiratory system is quite unusual. The pharynx and swim bladder of fish are covered with lung tissue, which allows the fish to breathe normal air. This adaptation has developed due to the low oxygen content in the waters of these freshwater rivers. Thanks to this, arapaima can easily survive drought.
Arapaima - lungfish The manner of breathing of this fish cannot be confused with anyone. When they rise to the surface for a breath of fresh air, then small eddies begin to form on the water surface, and then the fish itself appears in this place with a huge open mouth. All this action lasts just a couple of seconds. It lets out the "old" air and takes a new sip, the mouth closes abruptly and the fish goes deep. Adults breathe like this every 10-15 minutes, young ones - a little more often.
Huge mouth 
On the head of these fish there are special glands that secrete special mucus. But what it is for, you will find out a little later.
There are special glands on the head These giants feed on bottom fish, sometimes they can eat small animals, such as birds. In juveniles, the main dish is freshwater shrimp.
Bon Appetit The breeding season for Piraruku is in November. But they begin to create pairs already in August-September. These giants are very caring parents, especially males. Here I immediately remembered how the male "sea dragons" take care of their offspring. These fish do not lag behind them. The male digs a shallow hole about 50 centimeters in diameter near the coast. The female lays eggs in it. Then, during the entire period of development and maturation of eggs, the male is next to the clutch. He guards eggs and swims near the "nest", while females drive away fish swimming nearby.
After a week, fry are born. The male is still next to them. Or maybe they are with him? Young animals keep in a dense flock near its head, and even to breathe they rise together. But how does a male manage to discipline his kids like that? There is a secret. Remember, I mentioned about special glands on the head of adults. So, the mucus that is secreted by these glands contains a stable substance that lures the fry. This is what makes them stick together. But after 2.5-3 months, when the young grows up a little, these flocks disintegrate. The bond between parents and children is weakening.
Fry It was also noticed that among these fish there is widespread "adoption" of fry left without parents. After that, you sit and think that sometimes animals are much more human than people.
The longest river in the world is the Amazon. Together with the tropical forests that spread in its basin, it represents a whole separate ecosystem, full of the richness of species of flora and fauna. It is here that some of the most dangerous predators on the planet live, such as jaguars, caimans and anacondas. The swift waters of the river hide in themselves no less terrible monsters - piranhas, known for their powerful jaws and incredible gluttony. Among the more than 2,000 species of fish that inhabit the Amazon, the largest fish, arapaima (arapaima), also lives in the murky waters of the river.
Name
In science, it is known under the name Arapaima gigas, the name was given to it by the ancient Indians of Guiana. The Latin word "gigas" in translation means "giant". For many centuries, the indigenous people of Brazil have called it pirarucu "pirarucu" (purarucu) - "red fish" because of the bright color of the meat. In Peru, the common name is paiche - paiche.
The first study by scientists dates back to the beginning of the 19th century, a little later it was concluded that this is a fossil species that has not changed at all over the past millennia.
Definition
This bottom fish is considered a real giant, as it reaches 2 m on average, while its weight is about 90 kg.
Experts conducting observations claim that specimens of 3 m can be found in this region, and the maximum possible length of the largest fish on the Amazon is 4.6 m.But, unfortunately, these data have not been officially confirmed.
According to the stories of local residents, in 1978 in the Rio Negro in Brazil, a fish was caught 2.48 m long and weighing 147 kg. This fact was recorded in local chronicles.
Arapaima has a long body compressed on the sides, an elongated flat head, a wide mouth with sharp teeth on the tongue and palate (for secure fixation of prey). The dorsal and anal fins are long, the pectoral fins are located below. The color ranges from olive and gray (front) to dark red (rear) and black tail. As a rule, the male looks much brighter and slimmer than the female.
The main distinguishing feature is the presence of large embossed scales (4 cm wide), which are layered and characterized by incredible strength. It is this trait that allows the arapaima to survive in the company of piranhas during the dry months, when shallow bodies of water are formed, separated from the main water artery.
Compared to bone tissue, the strength of the scales is 10 times higher.
Local craftsmen make manicure tools and various souvenirs from strong scales, and the dried tongue is used as sandpaper.
Where does he live
The main region of distribution is the Amazon River in South America, on the territory of Peru and Brazil. Prefers silty places with dense vegetation, as well as swamps and flooded areas. The optimum water temperature is + 25 ... + 29 degrees Celsius, as it has an acute reaction to changes in the ambient temperature. In the dry season, it lives in rivers and lakes, in the rains it moves to flooded forests.
Behavior
The diet of this predator is based on small fish, small animals and birds, which are hunted almost on the surface of the water. Arapaima has the ability to breathe air, since its swim bladder and pharynx are densely covered with blood vessels, which are a kind of lung tissue. This function was formed due to the low oxygen content in the river, as a result of which there was a need for an additional respiratory organ. Floating up for a new portion of air after 5-20 minutes, creates a loud sound that looks like a cough, it can be heard at a considerable distance. In a drought, the fish, having drawn air, can burrow into the mud of the swamps and successfully wait out unfavorable conditions.
The first spawning (April-May) of arapaima occurs at almost 5 years old, when the body length reaches 0.6-2.15 m. Having chosen a shallow place, the female builds a nest-hole where she lays large eggs. Observations of their behavior have shown that it is possible to use the same nest for several years. After 1.5-2 days, the larvae appear, all this time the male is busy guarding the clutch, and the female controls the adjacent zone.
From males, exemplary and caring fathers are obtained: thanks to special glands on their heads with the secretion of mucus, the parent manages to keep the born generation next to him. The fry do not swim far away, since the secreted mucus contains a substance that attracts them, they are constantly in the flock next to the father's head. Also, together with it, they rise to the surface for air intake. After 3 months, this connection weakens. Fry growth per month is up to 5 cm.
Protection by the Convention
Due to uncontrolled fishing with nets and harpoons, this valuable commercial species may become endangered. Already, individuals larger than 2 m are extremely rare, especially in regions with a high population density, in some of them the catch of arapaima is already prohibited.
Today it is officially included in the Red Book and the list of species of wild flora and fauna that are in danger of extinction. Protected at the state level according to the international convention of countries and some environmental projects in South America.
To preserve the population, fishing is allowed only with a license from the Ministry of Agriculture in the amount strictly specified in the document.
Life in captivity
In order to preserve and reproduce the arapaima species, it was relocated to some waters of Malaysia and Thailand, where living conditions are as close as possible to the historical habitat region. There are also known cases of finding representatives of piraruku in zoos and large aquariums or swimming pools open to visitors in many countries of the world.
To create optimal living conditions in captivity, the following parameters must be observed:
- container volume - not less than 1000 l;
- water temperature - + 22 ... + 28 degrees Celsius;
- pH level - 6.0-7.5;
- water hardness - 2.0-15.0 units;
- active filtration, aeration and timely replacement of water.
The lifespan of individuals kept outside natural conditions is about 10 years.
Other inhabitants of the river
Among the variety of river fish in the Amazon, there are also some other edible varieties. According to taste criteria, the following varieties are considered the most popular in the craft of local residents:
- Aravana (Osteoglossum bicirrhosum).
- Brown pacu (Colossoma macropomum).
- Golden Spar (freshwater dorado) (Sparus aurata).
- Flathead catfish (Phractocephalus hemioliopterus).
- Haraki-Semaprochilodus (Semaprochilodus).
