Disappearing species of animals: Chinese river dolphin (baji)

In 1918 in one of the freshwater lakesthe Chinese province of Hunan was discovered an interesting object. In the lake Duntin noticed a water mammal that belongs to the suborder of toothed whales. The animal was called "Chinese river dolphin".

Who are river dolphins?

People are used to the fact that dolphins - residentssalty sea and ocean waters. But there is a small family called River Dolphins. Today there are 4 species of these cetacean mammals. Three of them live in fresh water, and the fourth can live in rivers and lakes, and in the ocean. Unfortunately, these are endangered species of animals. They suffer greatly because of their proximity to people. Dying out due to pollution of rivers and uncontrolled hunting.

What is the name associated with?

The local population calls the river mammal"baji". The Chinese river dolphin has a very characteristic dorsal fin, similar to a flag. This is what gave the spoken name to the whole species. The scientific name of the species is Lipotes vexillifer. It includes two concepts. Leipo means "forgotten", and vexillifer - "carrying the flag." As you can see, scientists also used external associations when they selected a name for a small species of mammals.

Description of the species

A freshwater representative of toothed whales,Chinese river dolphin, is a fairly large animal. The maximum fixed length of the body of a mammal was 2.5 m. And the minimum length of an adult is 1.5 m. The weight of an adult animal can range from 100 to 160 kg. The description of the dolphin is not too detailed. It is known that females of this species are large and exceed in size male individuals. The body of dolphins is dense and stocky. The neck is quite mobile. The pectoral fins have a wide base, but to the edge they seem to be chopped off with an ax. Dorsal fin flag medium in size, with smoothly rounded anterior and posterior margins. It is located not in the middle of the back, but closer to the tail part.

On the crown of the mammal there is a breathingoval shape. It is somewhat offset to the left of the center. The Chinese river dolphin sees poorly. His eyes are poorly developed and quite unsuccessfully located. They are high on the head, which reduces the viewing angle.

The front part of the cerebral cranium - the so-calledrostrum, it is narrow and elongated. It slightly bends upward and resembles the beak of a crane. The upper jaw has fewer teeth than the lower one. The maximum number of the top is 68 teeth, and from the bottom - 72 teeth.

It is impossible to compile a description of a dolphin without specifyingcolor of the animal. Baiji is a light blue or bluish-gray hue. Tummy in animals is white. Although some eyewitnesses claim that the color is much lighter than in the official description. They say that the Chinese river dolphin is almost white.

Distribution of the species

Most often this species of river dolphins was encountered inthe Yangtze River. If you saw what the Yangtze River looks like on the map, then imagine how deep and arched the artery is. Its length exceeds 6300 km, but this did not save the Chinese river dolphins from the threat of extinction. Occasionally, these mammals met in Qiantang (the river) and the lakes of Dongting and Poyang. One specimen was seen in the Shanghai area.

How does the species live and eat?

It is very difficult to study the way of life of this species. In connection with the small number, there is almost no information. It is only known that river dolphins are held in pairs and prefer the mouths of rivers and coastal shallows. Most likely, this is precisely the reason for the poor development of the sight organs in the species. The water here is always turbid, so the eyes are virtually useless, you have to rely on echolocation.

Chinese river dolphin leads a daily life. At night, he departs to the sites with a slow current to calmly rest.

In the diet of a mammal, small fish, blackheads, catfishand shellfish. For hunting, the animal uses a long beak. With his help, the dolphin digs out prey from the silt. To crush strong shells uses teeth that are specially adapted for this purpose.

Occasionally, river dolphins gather in groups. Such a group may consist of 3 individuals, and may include 15 animals. But these formations are not long-term.

Reproduction

On the reproduction of Chinese river dolphinstoo few. Scientists put forward assumptions, based on the grains of data held in their hands. Females are not too prolific. They bring one baby each and not more often than once every 2 years. Most likely, the period of gestation is 11 months. The cubs are born too weak. At first, the mother is forced to keep them afloat with her fins.

The exact period of puberty is not known. It is assumed that this can occur between three and eight years.

Attempts to save a view

Of course, scientists are trying to preserve the disappearingspecies of animals, but in the case of the Chinese river dolphin, no success was achieved. Despite the fact that the species is under protection and listed in the Red Book, there are virtually no animals in nature. The latest evidence of meetings of fishermen with this species of dolphins was received in 2004. In 2007, an expedition was sent to collect a number of different-sex individuals (about 25 animals). This could allow reproduction of the species in captivity and partially restore the population. But the expedition returned with nothing. Modern equipment did not fix the byze. This leads to a sad conclusion: the population of river dolphins has died out and will not be restored. It is regrettable to realize this, but since 2007 the Chinese river dolphin has been officially recognized as a disappeared species.