A graceful body, a smiling face, immense curiosity for a person and a cheerful disposition – all these are bottlenose dolphins. Or simply Dolphins, as many are accustomed to call this intelligent mammal.There are dolphinariums in many coastal cities, where everyone can make their dream to swim with dolphins come true at an affordable price. They show incredible friendliness to people, they are easy to tame. In general, dolphins have a very close relationship with humans. There was more than one case when these sea animals rescued drowning people in seemingly desperate situations.
Origin of the species and description
Modern marine dolphins are descended from a group of ancient toothed whales. They lived during the Oligocene period, but only in the next Miocene period, about 20 million years ago, 4 families emerged from this group, which exist to this day. Among them were river and sea dolphins with three of their subfamilies.
The bottlenose species comes from the genus bottlenose dolphin, a family of dolphins. They are large animals, 2.3–3 m (6.6 and 10 ft) long, some reaching 3.6 m (13 ft), but are quite rare. Bottlenose dolphins weigh between 150 and 300 kg (330 and 650 lb). The characteristic feature of dolphins is a developed “beak” on a long, almost 60 cm (23 inches) skull. The dolphin’s face resembles the old-fashioned gin bottle, from which their common name derives.
The teeth are strong, conically pointed, 19-28 pairs above and 1-3 pairs less down. They are located so that there are free spaces between them. When closed, the teeth of the upper row fall into the spaces between the teeth of the lower row.
The back color of bottlenose dolphins is dark gray, on the belly it turns into bright white or beige. Rarely seen with a pattern on the sides. The patterns are not as pronounced and not too noticeable and change with frequency. The dorsal fin is high, in the form of a crescent; it widens significantly at the base. The pectoral fins also have a wide base and then taper towards a sharp tip. Fins, in addition to their main function, also participate in heat exchange, since there are no sweat glands in the dolphin’s body. The fins of a dolphin thrown ashore very quickly overheat and, if you do not help him, moisturizing them, they will simply stop working.
They swim fast and easily reach speeds of up to 50 km / h (30 mph) and jump heights of up to 5 m (16 ft). The lungs serve as their respiratory organ. They capture the air not like people with their nose, but with a blowhole. Thus, they manage to hold their breath under water for at least 15 minutes.
Dolphin skin has good regenerative properties. Their wounds heal 8 times faster and more efficiently than human wounds. Bottlenose dolphins can handle pain with ease. In such cases, their body itself produces an anesthetic that resembles morphine.
Interestingly, they can recognize tastes, distinguish between sweet and salty, sour and bitter.
Anyone who at least once in his life heard the sounds of the bottlenose dolphin will never be able to forget them. Their language is unusual and painfully interesting. It is worth talking to them for a short time to understand what sound the bottlenose dolphins make. They whistle and chirp when they need to communicate something to their fellows.
Ultrasonic communication works for them when they need to understand the situation, identify possible interference, as well as during the hunt. People have long learned to use these sonar sounds of dolphins in treatment.
The vocal apparatus of the bottlenose dolphin is another amazing phenomenon. Air sacs (there are 3 pairs in total), interconnected by the nasal passages, allow these mammals to produce various sounds with a frequency of 7 to 20 kHz. In this way, they can communicate with relatives.
Bottlenose dolphin lifestyle and habitat
Bottlenose dolphins are found in almost all warm waters of the world’s oceans, as well as in temperate ones. In the waters of the Atlantic, they are distributed from the southern borders of Greenland to Uruguay and South Africa.
In the Indian Ocean – from the Red Sea in the north to the southern latitudes of the African continent and Australia. The Pacific Ocean includes Japan, Kuril Ridge, Oregon, Tasmania, New Zealand, and Argentina. The total number of individuals in the population is currently unknown.
These interesting creatures prefer to lead a settled lifestyle. They huddle in small flocks, live, breed, hunt. Daytime is selected for hunting. Sleep at night on the surface of the water. And during the day they swim and frolic with each other. During the hunt, they can stray into a group.
In search of food, the dolphin can dive up to 150 m (500 lb) in some places and even deeper in others. For the normal well-being of an adult, 8-15 kg of fish products are needed per day. Bottlenose dolphins gather in small groups to hunt other inhabitants of the deep sea: shrimp; sea urchins; electric rays; flounder; some types of sharks; octopuses; shellfish.
Dolphins are active mainly during the day. At night, they sleep near the surface of the water, often opening their eyes for a couple of seconds and closing them again for 30-40 seconds. Weak, unconscious strikes of the fin on the water push the body out of the water for breathing. An inhabitant of the water element cannot afford to fall asleep soundly. And nature made sure that the brain hemispheres of the dolphin slept in turns!
Social structure and reproduction
Dolphins have very developed social connections. They live in large flocks, where everyone is related. They readily come to each other’s rescue, and not only in pursuit of prey, but also in dangerous situations. It is not uncommon – cases when a flock of dolphins killed a tiger shark, which
dared to attack a baby bottlenose dolphin. It also happens that dolphins rescue drowning people. But they do this not out of noble motives, but most likely by mistake, mistaking a person for a relative.
For males and female bottlenose dolphins, pronounced sexual dimorphism is not characteristic. Usually males are slightly larger than females. The breeding season for bottlenose dolphins is spring and summer. Pregnancy lasts 12 months. Bottlenose dolphin, like humans, is a viviparous mammal.
Childbirth lasts from a few minutes to a couple of hours. The cub comes out tail first, the umbilical cord breaks easily. The newborn, pushed by the mother and another 1-2 females to the surface, takes the first breath in his life. At this moment, a certain excitement literally covers the whole flock. The cub immediately looks for the nipple and eats the mother’s milk every half hour.
The baby does not leave the mother for the first few weeks. Later he will do it without any obstacles. However, milk feeding will continue for about 20 more months. Although dolphins can eat solid food as early as 3-6 months, as happens in captivity. Sexual maturity occurs at the age of 5-7 years. The life span of the bottlenose dolphin in the wild is about 25 years.
Natural enemies of bottlenose dolphins
Even such intelligent and large animals as bottlenose dolphins cannot live peacefully. Many dangers lie in wait for them in the ocean. Young or weakened bottlenose dolphins are hunted by Katran sharks, which are quite small in themselves. Large predators like tiger sharks and great white sharks can attack the bottlenose dolphin and are more likely to win. Although the dolphin has more agility and speed than the shark, mass sometimes predominates. The shark will prefer to swim away from the pack of bottlenose dolphins.
Population and status of the species
Every year in the world there are mass killings of dolphins, including bottlenose dolphins, because of their meat, a number of individuals are also caught for dolphinariums. Dolphins die, entangled in nets, fishermen shoot them. In addition, a person catches a large number of fish that dolphins eat.
Harmful substances that pollute the waters of the oceans enter the tissues of animals, accumulate there and provoke many diseases and, most importantly, miscarriages in females. A film of spilled oil can completely block the breathing of bottlenose dolphins, from which they die a painful death.