Detailed data of baiji dolphin

White dolphin (scientific name: Li Potes Vexillifer), a small freshwater whale unique to China, is found only in the middle and lower reaches of the Yangtze River and its nearby rivers and lakes. It is considered to be the most endangered aquatic mammal at present, and is known as "the goddess of the Yangtze River" and "the giant panda in the water".

The baiji dolphin is an ancient relic of its family. Fossil evidence shows that it appeared in the Yangtze River in Pliocene 5.3 million years ago. Since the late 20th century, influenced by human activities, the number of wild animals has drastically decreased, and it was listed as the first-class protected wild animals in China in 1989, but the remaining population is still gradually extinct.

Since 1980, Qiqi, the only captive male baiji, has become an important source of relevant information, but there is no exact living record of Qiqi after his death on July 14, 2002. On August 8, 2007, the Royal Society published a report in the journal Biological Letterhead, announcing the functional extinction of baiji. 2018165438+1October 14, updated and released by the international union for conservation of nature, and the baiji dolphin has not been confirmed to be extinct, maintaining its original "extremely dangerous" rating.

Basic introduction Chinese scientific name: bái jì tún, alias: mackerel, mackerel (ancient name); Baibo dolphin, Baibo dolphin, China finless porpoise, Yangtze finless porpoise and Yangtze puffer fish: Lipotes vexillifer Miller, 19 18: Animal kingdom: Chordata: Vertebrate → Submandibular: Quadropod → Subspecies: Monotypic species with no subspecies differentiation. Distribution: The middle and lower reaches of the Yangtze River and adjacent rivers and lakes in China. China baiji's old English name: China finless porpoise IUCN rating: CR (extremely endangered, possibly extinct) Species naming, Chinese name, English name, appearance characteristics, living habits, distribution range, growth and reproduction, protection level, phylogeny, endangered reasons, internal factors, human factors, protection records, species naming Chinese names: baiji, baiji and Cooper. According to Zhou Kaiya, an expert in cetacean research, this kind of mackerel can be detected. Erya: "Mackerel is mackerel." Guo Pu, a scholar in the Jin Dynasty, made a note for Er Ya, noting that "Mao is Mao" is as follows: "Mao? Genus also. Body like pomfret. Like a tail? Fish. Big belly. The beak is small, sharp and long. Luo Sheng, upper and lower titles. The nose is on the forehead and can be silent. Eat less meat and more cream. Viviparous healthy fish. The big ones are long and redundant. There are many in the river. " Therefore, "Baidolphin" is the correct Chinese scientific name, and "Baidolphin" is obviously misspelled. The formulation of "Baidolphin" has been influenced by the simplification movement of Chinese characters since 1955. A large number of rarely used words, including Mao, have become "death" and have not been included in the simplified Chinese characters published by the state, so some scholars gave it up and changed it to "fin", indicating that it is a kind of freshwater dolphin with white inner fin. However, after the "2006 Yangtze River Freshwater Dolphin Survey", the names in the media are still different. Among the intelligent ABC pinyin input methods commonly used by China people, only "Baibo dolphin" is a word, so it is used the most, followed by "Baibo dolphin", and "Baibo dolphin" is used the least as the most standardized name. English name 19 At the end of this year, an American biologist went to the Yangtze River valley in China to investigate the geography and biology, and observed this species when fishermen cooperated in fishing. Later, an adult specimen was collected from fishermen and brought back to Washington for research. It was named Chinese finless porpoise. For nearly a century, this name has been very popular in cultural publications, especially in Nature magazine, and has been adopted by China scholars. However, in recent years, due to the growing influence of China's traditional culture in the world, academic circles began to attach importance to China's literary research achievements, and the earliest discovered literature or the earliest published research report was given priority. Therefore, the official English name of baiji was changed to baiji. Qi Qi (1978—2002), the only male baiji, is artificially reared, with a spindle-shaped body, hairless skin and constant body temperature, generally around 36℃. Adults are generally light blue-gray in the back and white in the abdomen, which is particularly bright under sunlight, and the newborn larvae are slightly darker in color. The upper and lower surfaces of the horizontally extending flippers and caudal fins are the same color as those of the back and abdomen, respectively, so the color distribution is just consistent with the environmental color. When looking down from the water, it is difficult to distinguish the blue-gray back from the river; When looking up from the bottom of the water, it is difficult to find that the white abdomen is similar to the strong light reflected from the water. This makes the white dolphins have a natural hidden barrier when fleeing from the enemy and approaching the prey. The snout of the baiji is long and narrow, about 30 cm. The front end is slightly upturned, and the closed line of the back corner is slightly raised, which looks like a smile. There are about 130 conical teeth of the same type in the mouth. Due to the limitation of temporomandibular joint function, it can not be used for chewing, but it can kill the prey instantly and effectively fix the prey firmly in the mouth to prevent it from breaking free. The eyes are small, behind and above the corners of the mouth. Ear holes are needle-shaped It has a circular jet nostril, located on the left side of the head. The flippers are wide and the ends are blunt and round; The dorsal fin is low and triangular; The female's caudal fin is crescent-shaped and larger than that of the male. The total length of adults is1.5-2.5m, and the final body length is 2.3m for males and 2.5m for females. The weight is 90- 150kg, and the limit weight is 230kg. In addition to baiji, finless porpoise and Chinese white dolphin, there are three species of cetaceans * * listed as first-class protected animals in China (finless porpoise was originally a second-class protected animal, and was upgraded to first-class protected animals by the Ministry of Agriculture in May 20 17). These three species are often confused. In fact, their morphological differences are significant, and they belong to different groups in evolutionary pedigree, and there is no close genetic relationship between them. The finless porpoise is actually a subspecies of Yangtze finless porpoise, belonging to finless porpoise family. It is smaller than the baiji, with a short and blunt nose and no dorsal fin. There is another offshore subspecies of East Asia, N.a.sunameri, which lives in China, Korean Peninsula and Japanese coastal waters north of Matsu Islands. The COVID-19 finless porpoise is a close relative of the narrow-tailed finless porpoise, which is distributed in the southern part of Mazu Islands and extends westward along Southeast Asia, South Asia and West Asia to the coastal waters of the western Pacific Ocean and the northern Indian Ocean in the Persian Gulf. "Chinese White Dolphin" is the common name of China Pacific camel dolphin (Sousa chinensis). It belongs to the dolphin family and is a veritable "dolphin". It is distributed in the western Pacific and Indian Ocean, and does not live in the Yangtze River. Its size is larger than that of the baiji, and the baiji populations in the East China Sea and South China Sea of China are pink when they grow up, which is obviously different from the bluish gray of the baiji. In addition, Chinese white dolphins often jump out of the water, while white dolphins are shy by nature and only show their heads and backs when breathing. Surfing and jumping on the water, full of vitality, are basically Chinese white dolphins Living Habits The baiji dolphin likes to live in groups, especially in the spring mating season, and the group behavior is more obvious. Each group is generally 2- 16. It has a wide range of activities, but it needs high water temperature. It often stays in a fixed area for a period of time, and then moves to another area after the water temperature changes. The baiji dolphin likes to live in the deep water area in the center of the river, and occasionally enters the confluence of lakes, tributaries and mainstream. Timid, shy, rarely close to the shore and ships, but often swim to shallow water in the morning and evening to prey on fish and shrimp. The baiji dolphin has poor eyesight. It finds food through its own ultrasonic signal and then suddenly swallows it. It has a strong digestive ability, and the food it catches is swallowed without chewing. Eat a lot, and the general food intake can account for 10%- 12% of the body weight. The prey is mainly fish with a body length less than 6.5 cm, but also a small number of aquatic arthropods and aquatic plants. Baiji dolphins breathe with their lungs. Every time he breathes, the top of his head and breathing holes first emerge from the water, and then his back emerges from the water. The breathing time of the water is about 1-2 seconds, each diving time is about 20 seconds, and the long-term diving can reach 200 seconds. Come out for air every minute or two, sometimes spray water, and make a sound when you breathe out. When the weather is sultry and shanghai dawn, it will frequently appear from the water and fall together. People call it "Bai Qiu Bai Jiang". Its distribution ranges from 35km upstream of Gezhouba in Yichang, Three Gorges area to the Yangtze River estuary near Shanghai, including Dongting Lake and Poyang Lake. There are baiji dolphins in the river with a total length of about 1700 km. However, due to the long-term influence of human activities, its population number and distribution area have gradually shrunk. Later, it was limited to the middle and lower reaches of the Yangtze River and its adjacent waters such as Dongting Lake, Poyang Lake and Qiantang River, especially in Hubei, Hunan, Anhui and Jiangsu sections below Shashi District of Jingzhou City. In the1990s, baiji disappeared in Dongting Lake and Poyang Lake. The upper limit of its distribution in the Yangtze River has also moved to Jingzhou, downstream of Gezhouba170km. Its lower limit has been lowered seriously, and it is hard to find it near Nanjing. During the observation period from 1997 to 1999, it was not found below Jiangyin near the lower reaches of Nanjing. During several observations from 2000 to 2004, its distribution was mainly limited to three areas: Tongling section, Jiujiang section and Honghu section of the Yangtze River. The last time it was confirmed that the baiji dolphin was found in the wild was a stranded corpse found in Nanjing section of the Yangtze River in August 2004. From June165438+1October 6, 2006 to June 65438+February 65438+March 3, 2006, nearly 40 scientists searched the river section from Yichang to the middle and lower reaches of the Yangtze River in Shanghai, and found no baiji, so many scientists suspected baiji. However, it can be inferred that there are still a few remnants in the middle and lower reaches of the Yangtze River, but it is difficult to continue the population only by these last few individuals. White dolphins can live up to 30 years. The male is 4 years old and the female is 6 years old. In the wild, the adult sex ratio is 1: 1, but the female pregnancy rate is generally only 30%, and the natural reproduction rate is very low. Adult females have two periods in a year, from March to May and from August to 10. The gestation period is10 ~1month, and the delivery is 1- the following February. It breeds every two years, and each offspring has 65,438+0 offspring, and occasionally twins, and the birth time is about 80 cm. Newborn dolphins maintain energy by sucking their mothers' milk and move with the group. The protection level is listed in Appendix I of CITES. It is listed in the American Endangered Species Protection Act. It is listed as Grade I in the List of National Key Protected Wild Animals in China. It is listed in the IUCN Red List of Endangered Species (VER 3. 1-Cr (extremely endangered and possibly extinct). Systematic occurrence From the early 20th century to the 1970s, four species of freshwater dolphins in the world (South Asian puffer fish, baiji dolphin, Amazon puffer fish, La Plata puffer fish) all belong to one family, that is, the family tetrodotonidae, also known as Cephalopodidae and Freshwater Dolphinidae. 1978 after the publication of the newly constructed baiji family, scholars from all over the world studied the phylogenetic position of baiji by different methods. In recent years, morphological, paleontological and molecular systematics studies show that freshwater dolphins are not a single line, South Asian puffer fish are closer to the bottom of the phylogenetic tree than the other three species, and baiji, Amazon dolphin and La Plata puffer fish represent the subordination. After nearly a century of research, freshwater dolphins are parallel, the four existing genera of freshwater dolphins belong to four independent families, and baiji dolphins are at least one family. These three points have become knowledge of cetaceans. There are few internal causes of endangerment, so it is difficult to breed in large quantities. Low reproduction rate and slow growth. Due to human factors, human beings overfished fish and shrimp, resulting in insufficient food supply for baiji. Over-exploitation of the Yangtze River by human beings has seriously disturbed and destroyed the habitat of the baiji. The chemical plants and pharmaceutical factories built by human beings near the Yangtze River have seriously polluted the water quality of the Yangtze River. The Yangtze River has become a very busy waterway, and many baiji dolphins have been killed and injured by the propellers of ships. Due to the increase of human activities or improper activities, the number of accidental deaths of baiji has increased. According to statistics, during the period of 1973- 1985, there were 59 accidental deaths in * * *, of which 29 were caused by fishing hooks or other fishing gear, accounting for 48.8%; Death from blasting operation in the river 1 1 head, accounting for18.6%; Ship propeller killed 12 head, accounting for 20%; 6 heads were stranded and died, accounting for10%; 1 head mistakenly entered the sluice, accounting for 1.6%. According to statistics, one third of the accidental deaths of baiji in the lower reaches of the Yangtze River were killed by ship propellers. Protection record 1978 Wuhan Institute of Hydrobiology, Chinese Academy of Sciences has set up a research group on baiji, and officially started the research work on baiji. In the same year, the State Council promulgated the Regulations on the Protection of Water Resources and the General Order on Strict Protection of Precious and Rare Wild Animals, both of which listed baiji as the key protection object. 1980 65438+ 10 In October, fishermen in Jiayu County, Hubei Province accidentally caught a young male dolphin near the mouth of Dongting Lake, and then sent it to the Institute of Aquatic Sciences of Chinese Academy of Sciences for artificial breeding, named Qiqi. In the same year, Hubei Province * * * issued the "Notice on the Protection of Precious Animals". 1983, China declared it illegal to hunt baiji. From 65438 to 0986, the international symposium on biological protection of freshwater dolphins was held in Wuhan, and the baiji dolphin became a topic of concern to scientists at home and abroad. Chen Huamu, then president of the Bank of China, donated 500,000 US dollars to the baiji. On September 27th of the same year, the Institute of Aquatic Sciences of China Academy of Sciences captured a female dolphin named "Pearl Krabs" and died on the date of 1988. 1989 65438+1October 14 The Ministry of Forestry and the Ministry of Agriculture issued the List of National Key Protected Wild Animals, and the baiji was listed as a national first-class protected animal. 1992, the Ministry of Agriculture approved the establishment of two national nature reserves of baiji, Shishou Swan Island in Hubei and Xinluo River in Hubei, and approved the establishment of five protection stations, namely Jianli in Hubei, Chenglingji in Hunan, Hukou in Jiangxi, Anqing in Anhui and Zhenjiang in Jiangsu. 1995 An adult female dolphin was captured in Shishou River section of Hubei Province, and kept in Baiju Dolphin Nature Reserve, the old course of the Yangtze River in Swan Island, Shishou. 1996 died after hitting a net in the summer flood of the Yangtze River. 1996 12.23, Wuhan Baibo Dolphin Protection Foundation was formally established. 1In August, 1997, the "Yangtze River Treasure Baiji Dolphin Exhibition" was held in beijing museum of natural history. In September, 2000, Wuhan invested 600,000 yuan to hold the popular science exhibition "Saving Baibo Dolphin". It was originally planned to receive 200,000 to 300,000 people, but the final number of visitors was 167 1, so it was forced to withdraw the exhibition in advance. In March 2002, Tao Xingshi, a member of Chinese People's Political Consultative Conference, put forward a proposal to strengthen the protection of baiji at the CPPCC meeting. On July/0/4 of the same year, the white dolphin Qiqi died. In August 2004, a dead baiji was found stranded in Nanjing section of the Yangtze River, which was the exact record of the last time baiji was found. During the period of165438+1October 6-65438+February 65438+March 3, 2006, nearly 40 scientists from China, the United States, Britain, Japan, Germany and Switzerland visited the Yichang-Shanghai section of the Yangtze River 1700 km. On August 8, 2007, the Royal Society published a report in the journal Biological Letterhead, announcing the functional extinction of baiji. 2018165438+1October 14, the IUCN red list of endangered species was updated and released, and the status of the baiji dolphin is still "extremely dangerous", and its extinction has not been confirmed.