Do you know about this animal on our planet? Where it lives, what is it called and why it is pink. I once heard this information, but now when I saw him in the photo again, I was still surprised and had to find out all these details again.
Let's get together then …
For some it will be a discovery, but it turns out that there are freshwater dolphins.
River dolphins are found not only in the Amazon; they can also be found in the Indian Ganges, in the Pakistani Indus and in the waters of the Rio de La Plata between Argentina and Uruguay. There are four types of river dolphins in total.
Until recently, there were five species of river dolphins. However, already at the beginning of our century, dolphins from the Chinese Yangtze River were completely destroyed - since 2002, scientists have not been able to detect them.
There are several species of river dolphins in South America. The largest of these bears the beautiful name of the Amazonian inia, or bouto.
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The ancestors of the inia - plicodontins - entered the Amazon about 15 million years ago from the Pacific Ocean. At that time, the Andes were still growing and did not represent a continuous chain, so the Amazon did not flow into the Atlantic at all, but into the Pacific Ocean. Modern inia is endemic to the Amazon, Orinoco, Tocantins and some of their tributaries flowing in Venezuela, Colombia, Ecuador, Brazil and Peru.
Why did dolphins, the original inhabitants of salty sea waters, move to fresh water bodies? Healy Hamilton, a biologist at the California Academy of Sciences, explains that about 15 million years ago, during the Miocene, the sea level was higher, and therefore vast parts of what is now South America were under a layer of salt water. Hamilton's hypothesis is that over time, the sea gradually receded to its present borders, and some of the dolphins remained in their former territories. And over millions of years in the Amazon basin, they have turned into completely amazing creatures, not much like everyone's favorite, the movie hero Flipper.
Pink is not the only way to attract a female. Sometimes the bowto takes a bunch of plants or a piece of wood in its beak, begins to circle and beat its prey in the water. Locals thought for a long time that this was just a game, until Martin discovered that only males hold objects in their mouths - and only in the presence of females.
At first glance, all freshwater dolphins appear to be the same, Hamilton said, but their four genera belong to three different families. Based on DNA analyzes, river dolphins separated from their common ancestors, the ancestors of cetaceans, in at least three cases - first in India, then in China and South America. The evolution of each of the families proceeded independently and in parallel - geographically isolated and genetically different species, adapting to similar conditions, eventually acquired similar characteristics.
Each spring gives Amazonian dolphins a chance to leave the narrow boundaries of the river bed and remember their ancient endless homeland. Tony Martin of the University of Kent in England has been studying dolphins in the Mamirahua Nature Reserve in western Brazil for 16 years. Here, two tributaries of the Amazon flood thousands of square kilometers of jungle for six months, turning them into a huge lake under the tree cover.
Martin and his Brazilian colleague Vera da Silva found female dolphins swimming deeper into the forest, possibly hiding from aggressive, hot pink males. Females are mostly gray in color; but males, according to Martin and da Silva, acquired their cute pink color as a result of multiple wounds.
“Large males have no living space from scars,” says Martin. "They fiercely fight for life and death: they bite off each other's jaws, tails, fins, and tear apart the breaths." There are few bright pink males, but they are the ones that have the greatest success with females - at least during the mating season, when the water returns to the riverbed and the females are forced to swim back from the deep jungle.
Pink is not the only way to attract a female. Sometimes the bowto takes a bunch of plants or a piece of wood in its beak, begins to circle and beat its prey in the water. Locals thought for a long time that this was just a game, until Martin discovered that only males hold objects in their mouths - and only in the presence of females.
In addition, during this demonstration, the probability of a fight among males increases 40 times. It turns out that bouto, trying to impress their friends, brag about the items they don't really need. “It's like some guy starts showing off his Ferrari,” explains Martin. By the way, besides dolphins, only monkeys and humans use items for bragging.
According to ancient local beliefs, bouto is a magical creature that can change its appearance. Sometimes it comes out of the river in the guise of a man to lure gullible men and women into a fabulous underwater kingdom. They even say that dolphins wear hats so that their breath and bulb-like head cannot be seen.
Inya grows in length up to 2 meters or more, gaining weight over 90 kilograms. Like other freshwater dolphins, female inia are usually larger than males. Including known dolphins, which grew up to 250 centimeters and weighed almost a centner. Although the record for mass (160 kilograms) still belongs to the male.
The skin color of the inia is pale gray, sometimes the back has a pinkish or pale blue tint. The belly of dolphins is usually whitish. Lakes are often colored darker than those that prefer to stay in rivers. In addition, the color of adults depends on the temperature and purity of the water, as well as on the geographical location. In 1974, in Venezuela, an absolutely white female inia (albino dolphin) was caught and kept in the aquarium.
A distinctive feature of a river dolphin from a sea dolphin is a long, leathery snout, similar to a beak or sting. It is very convenient for them to dig crustaceans from the bottom silt and catch fish. The amazing structure of the cervical vertebrae that do not grow together, gives them the ability to turn their head at an angle of 90 degrees in relation to the body! The movable head facilitates orientation, and the elongated snout is convenient for examining and sniffing debris from branches on the river bottom.
Dolphins are looking for prey with the help of echolocation, because in muddy water there is little sense of sight, and disoriented fish in such conditions becomes easy prey.
The animal usually swims at a speed of 3-5 km / h, but is capable of accelerating to 18-22 km / h. Inia is found in those parts of the river where the Amazon floods most during the rainy season, flooding the surrounding Igapo forests and swamps. With the onset of the dry season, the dolphin returns to the main channel of the Amazon and Orinoco, or through the preserved network of channels it makes its way into the deep lakes in the middle of the forest. The dolphin is too large to settle in shallow and rapid rivers. He also avoids those branches that have waterfalls.
Inia's favorite foods are various fish and crabs, and sometimes even small turtles. At the same time, the dolphin is not at all afraid of the most dangerous fish of the Amazon - the notorious piranhas. Piranhas are capable of tearing to shreds any animal that falls into the water with their sharp jaws, but, sensing the approach of an inia, they turn to flight. Dolphins easily catch piranhas and enjoy them with pleasure.
Inya is active at any time of the day, although it feeds only twice a day - from 6 to 9 and from 15 to 16 hours. Interestingly, the animal almost never sleeps. It is able to put one of the cerebral hemispheres to sleep, while the other continues to work as usual. The cerebral hemispheres take turns keeping watch, giving each other a rest, and the dolphin itself, as a result, is awake almost around the clock. At the same time, naturalists have repeatedly observed dolphins that really slept, stretched out along the bottom and closed their eyes.
Inii lead mainly a solitary lifestyle, uniting only during the mating season and raising offspring. The mating season for dolphins is October and November. The female bears the calf for 8-9 months. Childbirth takes place under water and lasts from 1.5 to 5 hours. The little dolphin is born gray and with a cat's antennae on its face. The length of its body is 80 centimeters and weighs up to 6 kilograms. For almost a year, the cub feeds on mother's milk, which is exceptionally rich in proteins and other valuable substances, but at the same time has a fat content of only 13%.
Parents and children do not part for a long time, they can often be seen playing together in the water. A dolphin becomes an adult when it reaches a certain length. Males should grow up to 200 centimeters, and females up to 160-170 centimeters.
The local population has different attitudes towards inya. In some villages, iny are revered, as these intelligent animals help fish and scare away flocks of bloodthirsty piranhas. In other places, the dolphin is viewed with distrust, considering it an insidious forest spirit. In the fairy tales of the inhabitants of the Amazon, inia is a werewolf, capable of turning into a man in the dead of nights. Flocks of such werewolves, assuming the guise of men and women, arrange midnight dances in the forest, trying to lure the late hunters and fishermen. The local belief about the magical power of the dolphin is so strong that when fishermen happen to find a dead inya, they prepare a love potion from her eyes.
Until now, humans and Amazonian dolphins have managed to live together peacefully. Therefore, the number of inia is quite high, so that the future of the species does not cause fears. However, if the pollution of the Amazon with industrial waste continues, the dolphin could become another human victim.
In the entire history of mankind, people have exterminated at least 106 species of mammals. And we have tamed only 15 species. Each of the animal species that have already disappeared and are disappearing before our eyes could become a faithful friend and helper of people. Dolphins are already happy to offer people their friendship and help in fishing. Obedient capybaras are easily tamed. The endangered oryx was once tamed by the ancient Egyptians - why not domesticate it again?
Humanity has already lost a lot. We would need herds of sea cows in algae pastures, mammoths in taiga logging areas … But more importantly, all kinds of animals are necessary not only for humans, but also for nature. Each living creature has its place in the ecosystems of the Earth, like a microcircuit in a computer. If you remove the part from the computer, it will stop working. Through our fault, wildlife has lost dozens of its "chips". And if people do not stop, then one day all animals and plants on the planet will disappear, and it will turn from a beautiful blue-white ball into a gloomy lifeless desert.
The Amazonian inia is the most successful species among river dolphins. However, in the lists of the International Red Data Book, it has the status of “vulnerable”.
Compared to the rapidly decreasing ranges of the lake and Gangetic dolphins, the range of the Inia remains stable, and the determination of the number is difficult due to the inaccessibility of its habitats. Presumably, it is in the tens of thousands.
However, Martin believes that only about 100,000 Amazonian dolphins remain in nature, and they are in great danger. In seven years, the population from the Mamirahua reserve has halved. Fishermen use dolphin meat as bait for catfish, and it is not uncommon for bowto to accidentally fall into nets and suffocate, unable to surface.
Population growth and anthropogenic pressure on the environment have a negative impact on the flock population. The decrease in the number of fish as a result of fishing is one of the problems. Hydroelectric dams both impede fish migrations and segregate outlaw populations, potentially reducing genetic diversity within subpopulations.
Deforestation in flooded areas leads to a decrease in the fodder base for fish that serve as food for almonds. Finally, pollution of water bodies with agricultural pesticides and heavy metals (including mercury) from gold mines has a particularly negative impact on dolphins and their food base.
Inium has no commercial value. Portuguese colonists previously hunted river dolphins for lamp oil, but locals traditionally do not use their meat or skin. The body parts of the dead ore go to amulets; fat in traditional medicine is used as a remedy for asthma and rheumatism.
In the folklore of the Amazon peoples, the boutos appear as reborn souls of the drowned, or as werewolves (encantado), taking the form of beautiful young men and women. In addition to driving piranhas away, anglers use their presence to spot schools of fish.
As a rule, they are caught by accident, when they inadvertently fall into fishing nets. They are also caught and destroyed by fishermen for damaging the nets and reducing the catch. Since 1988, this practice has been banned in Brazil and Bolivia and restricted in Peru, Venezuela and Colombia.