Bottlenose dolphins, the combat mammals
The indigenous inhabitants of the Black Sea, the bottlenose dolphins, have been settling the area for about 10,000 years ago when neither Russians, nor Ukrainians, nor even more Tatars have ever heard of. According to geneticists, the Black Sea bottlenose dolphins have been living separately for about 10 thousand years and does not interbreed even with their closest neighbours: bottlenose living in the Mediterranean Sea. This is a considerate period of time for the Black Sea bottlenose dolphins to evolve. To date, their physical traits developed as their caudal fin has become a little smaller, the “forehead” – melon, is more convex, and their body, on average, have become a little smaller and shorter. In 1940, Soviet scientists Barabash and Nikiforov proved that the Black Sea bottlenose had emerged as a subspecies Tursiops Truncatus Ponticus.
The Black Sea bottlenose dolphins have developed their body language. The poses that they take are not for nothing. They talk by the position of the body, by the movement of the tail, and by touching the fins. Their tail is powerful where they capable of speeds up to 40 km/h. Scientists believe that bottlenose also have developed underwater vision. The eyes of this dolphin move independently, each eye has an almost 180-degree field of view, which allows them to simultaneously capture the surface of the water, the abyss below, nearby relatives, and its own tail. Their pupil is round, like that of a fish, but these dolphins have two zones of best vision, allowing them to see well both underwater and on land. They have 40–60 identical sharp teeth, but instead to chew they only use them to hold the fish. They grind their teeth unevenly on the right and left. On this basis, left-handers and right-handers are divided. They breathe through their nostrils, which in the process of evolution moved to the forehead, and the number of nostrils was reduced to one. Their breathing is uneven and arbitrary, that is, they “consciously” decide that it is time to breathe. The cycle “exhalation – inhalation is noticeably short, less than a second, while the air in the lungs is renewed by 80%, whereas humans only by 10–15%. Before a deep dive, bottlenose breathe by taking several frequent breaths and exhalations.
The bottlenose dolphin’s brain weighs an average of 1,700 grams – more than a human’s; the surface of the bark is cut by numerous deep grooves. If put next to the human brain, the brain of the bottlenose is more complexly organized. However, experts have not come to a consensus whether this species have a highly developed brain or not. Yes, the areas of the cortex that are responsible for abstract thinking in bottlenose dolphins are quite comparable to that of humans. The total area of the cerebral cortex even exceeds the surface of the humans. However, the bark is very thin compared to other mammals and is not clearly divided into regions. In addition, in the cortex of the dolphin’s brain, there are no variety and complexity of nerve cell’s structure, as in most terrestrial mammals. This diversity determines the ability to complex signal processing. The life expectancy of bottlenose dolphins is comparable to that of a human: according to scientists, in the wild, males live on average 40-45 years, females a little more – about 50. And the longest-living record holder among them is the female Atlantic bottlenose Nellie from the Marineland Oceanarium, who died May 14, 2014 at the age of 61.
Bottlenose dolphins are not kind. The pack can be very tough showdown. They fight with rastrum, bites, hits sideways and with its tail. They bite their relative by the trunk of the tail. Despite that, dolphin, as well as bottlenose, is one of the ten smartest animals on the planet, along with elephant, dog, and monkey. They are highly organized, and their needs of an “intellectual” load is soaring, hence they are known as a very curious creature. Scientists study this by observing the dolphin’s passion to accompany ships. They come up with the theory of information content of space. The information is so important to the dolphin that they prefer to be in those places where something interesting is happening, even to the detriment of food.
Scientists estimate that at least 6 million dolphins were exterminated in the Black Sea for the last century. Whaling has flourished all over the world and has proven to be effective that it has brought some cetacean species to the brink of extinction. Bottlenose dolphins were hunted for industrial purposes such as fertilizers and animal feed. They also caught to carry out a range of military tasks. In the late 40s, American scientists did some research on this fascinating animal resulted in an assumption that they have the ability to use echolocation. In the mid-1950s, the scientist managed to prove this assumption in a series of experiments. This made it possible to utilize bottlenose dolphins as combatant. They use them as part of the country’s defence system: detection of submarines, underwater mines, and saboteurs. In strict secrecy, military dolphinariums are being built in San Diego and then in Hawaii to study and train dolphins. The Soviet Union followed in 1966 when the first Soviet military dolphinarium was built in Cossack Bay (Sevastopol).
It was in the 60s, when both Americans and Soviets were carried away by the opportunity to use bottlenose dolphins for military purposes and a whole series of scientific discoveries were made. Such discoveries aimed to made it possible to create them a tireless soldier. During these “sharp” experiments and while trying to implement the “brilliant” ideas of the military, the Americans hoped to train a bottlenose to blow up enemy ships as a living torpedo, the explosives were planned to be placed in the dolphin’s stomach. The Soviet military also had the idea to drop a bottlenose carrying explosives with a parachute. Fortunately for the dolphin, it turned out that she was not capable of carrying enough explosives and could not breathe at an altitude of more than one and a half thousand meters, and the projects were closed.
One important discovery is brought to light by Soviet scientists. They found out that half of the dolphin’s brain emitted slow waves as if it were asleep, and the other half continued to be awake. At first, scientists doubted if this was a mistake, but the picture was quite clear: the dolphin’s brain hemispheres slept in turns. While one hemisphere was resting, the other made sure that the dolphin could rise to the surface in time and take a breath. Hence, another riddle of dolphins was solved: intolerance to general anaesthesia. The fact is that, unlike humans, cetaceans have voluntary respiration, and if the animal is not conscious, then it does not breathe. But scientists cannot yet say whether dolphins are dreaming or not. During sleep, they swim in a circle. External signs of paradoxical sleep (the time when people dream) are observed, but the dolphin’s corresponding brain activity has not yet been recorded.
Bottlenose dolphin is one of the most perfect creations of nature. Human, as a society, would have to agree that this intelligent species deserve a bioethical status. Treating them brutally for personal gain is never acceptable. They turned out to be completely different from what we imagined them to be. They see with their ears but hear with their jaw, completely complex and unlike ours, but it is so harmonious and amazingly beautiful.
