Dolphins are marine mammals that belong to the suborder toothed whales. They are found in the seas and oceans, as well as rivers with access to the sea. As a rule, they feed on crustaceans, molluscs, fish, and some do not disdain sea turtles and birds.
There are more than thirty species of dolphins in the world, the most common of which are: killer whales (Orcinus orca), ball-headed dolphins (grinda - Globicephala), gray dolphins (Grampus griseus), Chinese lake dolphins (Lipotes vexillifer), common dolphins (Delphinus delphis) , bottlenose dolphins (Tursiops), and others. Dolphins cannot stay under water for a long time, so they periodically float to the surface for air. Males are usually larger than females, they are easily distinguished from each other by their fin - the male has a higher dorsal fin.
The gestation period of dolphins, depending on the specific species, lasts from 12 to 16 months. Basically, only one cub is born, which until about two years old is next to the mother and feeds on her milk. The average life span of dolphins is 20-25 years, but there are cases when some individuals lived up to 50 years.
Many legends have been written about dolphins, feature films have been shot and books have been written. Among other things, there are many myths about these animals. Let's consider some of them.
Dolphins rescue drowning people. Perhaps this is true. But scientists are quite skeptical about this statement. They are more inclined to believe that these animals just love to play, nudging the object with their nose. Also, they have a natural reflex associated with the birth of a baby: the flock amicably "pushes" a newborn dolphin to the surface so that it can breathe air. In addition, the animal must, firstly, realize that a person is actually drowning, and secondly, figure out how to save him.
This is a very intelligent animal. On this score, there have been, are, and, probably, always will be, heated debates among scientists. Some believe that dolphins are superior to humans in their mental development. Others argue that the mental abilities of these mammals can only be compared with that of a dog and chimpanzee. In general, opinions are divided, however, "ordinary" people (not scientists) who have ever come into contact with these animals say that dolphins understand everything, they just cannot say.
Dolphins hear nothing. These animals have an inner ear, thanks to which they hear perfectly underwater. In addition, their hearing is very acute and they tend to hear sounds in the range from 16 hertz to 280 kilohertz. While in humans, the hearing threshold does not exceed 20 kilohertz.
Dolphins have good eyesight. Some species of dolphins cannot be said that way. For example, the "susu" dolphin living in the Indus River of Pakistan is blind. And why should he see if the water in this river is muddy and it is impossible to see anything in it. How does he live then? Thanks to the natural sonar, that is, the sonar. With the help of this "device" dolphins seem to "feel" everything that surrounds them, and can accurately determine the location of this or that object.
Dolphins help fishermen catch fish. It is common knowledge that a friendship usually develops between a man and a dolphin. And the people involved in the fishing industry "use" this friendship "wisely." For example, a few fishermen enter the sea and begin to be sticks on the water. Dolphins, attracted by this noise, flock to the shore, thereby "pushing" schools of fish ahead of them. Thus, the fish fall into the fishing nets, and the dolphins swim back into the sea, but return again, barely hearing the familiar noise.
Dolphins can always recognize a specific person. This is not entirely true. If a dolphin meets a person on land, then he will not recognize this person in the water. Conversely, having met a person in the water, the dolphin does not recognize him on land. That is how they are arranged.
Dolphins do not understand human speech. It would be more correct to say - they do not hear a person's speech well. This is due to the fact that dolphins seem to be "tuned" to their wave (frequency), on which they communicate with each other. Therefore, in dolphinariums, instead of a voice, they use a whistle - for dolphins it is more understandable. But they perfectly hear and even feel music. Also, these animals understand hand movements and facial expressions well.
These mammals are able to cure humans of all diseases. This is not entirely true. For example, a paralyzed person after dolphin therapy will still not be able to live a full life, but his mental (moral) state will improve much. Most often, dolphins manage to heal people who have various nervous diseases or deep depression. How they do it is still unknown. Scientists believe that it is all about the special ultrasonic radiation that comes from the animal. When a dolphin communicates with a healthy person, then he publishes a calm clicking; if the animal feels that the person is sick, it begins to rumble. After such "sessions" the dolphin gets very tired and tries to be alone to gain strength. Therefore, dolphin therapy is in increasing demand, and this is not an invented fact.
Dolphins are used in military service. Yes this is true. These animals were especially often used during military operations. Dolphins acted both as scouts and even as killers. Now they mainly act as guards of sea borders.
Dolphins are very aggressive creatures. Too strong. Of course, do not forget that a dolphin is an animal, and aggressive behavior is inherent in all animals, especially during the period of sexual attraction. Better not to get in the way of the dolphins in love - the aggressiveness will manifest itself in full! Also, if the dolphin thinks that he is tired of communicating with a specific person, he can also show his displeasure. In other cases, they are quite sociable and peace-loving animals.