means the successful natural survival stage of wild Amur sturgeon. This Yangtze sturgeon is 96 cm long and weighs about 8 kg. It is presumed to be a sub-adult individual, with a fish age of 5-6 years. It is expected that it will be sexually mature in another 2-3 years (7-12 years in the wild and 6-8 years in the artificially propagated individual). Judging from its growth state, it has lived in the wild for a long time, and its physical condition is relatively good, which also gives hope to the recovery of Acipenser Changjiang, but there is still a long way to go before it forms a wild population.
1. judging from the appearance, the artificially bred individual is light in color, but no marking method is found. This Yangtze sturgeon is also an artificially bred individual who has been wild in the past wild proliferation and release activities. Yuan Xia said that this does not mean that the wild Amur sturgeon has been successfully released. What he means is that it is successful to resume natural reproduction, focusing on natural reproduction, which is also expected by everyone. Artificial breeding animals can be restored to wild animals, and when the wild population is restored, it will go through the processes of wildness, wild release, natural survival, natural reproduction, minimal population recovery, wild population recovery and so on. Giant pandas and Siberian tigers are going through this process.
At present, the emphasis is still on natural survival, so I think that in the natural survival stage, the wild Amur sturgeon has been successfully released. Species extinction in the wild means that a species has not found individuals in the wild within 5 years, which means that the species is extinct in the wild, which is extinction in a narrow sense. China's endemic species, ACIPENSER Changjiang, has not found any wild individuals since 1983 (39 years ago), and it will be shortened if it is declared extinct in the wild in 22. Fortunately, the artificial breeding of the Yangtze sturgeon has been successful.
Second, the complete extinction of a species means that within 5 years, a species has not found any individuals in the wild, and the captive individuals have also died, which means that the species is extinct in the wild and captive, and completely disappears in this world. On November 1st, 22, the endemic species of China, the white sturgeon (Psephurus gladius), was caught in the wild, but failed to carry out artificial conservation, and committed suicide by hitting a wall. No wild individuals were found since then. IUCN, the World Conservation Union, officially declared complete extinction on July 21st, 222.
I remember some experts think that the culture pond is too small and the culture environment is quite different from the wild environment, so it can't adapt to it. Perfection of Total Artificial Propagation System of Sturgeon In 1976, Chongqing Institute of Fishery Science carried out the artificial propagation of Sturgeon, and from 1976 to 198, it completed the full artificial propagation and domestication process from fertilized eggs to adult fish and then spawning. The establishment of this system played an important role in the protection of Chinese sturgeon, ACIPENSER davidianus (ACIPENSER Changjiang), ACIPENSER davidianus and other species. After the establishment of artificial propagation system, in order to create economic benefits, related technologies were further improved in 1994.
Third, in the international market at that time, 1g roe sauce could fetch 2, yuan, which was called black gold. However, the sturgeon Russian sturgeon 14-16, Chinese sturgeon 14-26, ACIPENSER davidianus 6-8 and Siniperca davidiana 16-2 have a long sexual maturity. At that time, the cultured species were mainly Chinese sturgeon and Siniperca davidiana, which was not conducive to obtaining fish eggs. After a series of technical breakthroughs, the hybridized sturgeon can get fish eggs in seven years, and the survival rate of the live egg retrieval technology reaches 93, and the technology is mature around 217, so that 1g fish seed paste is reduced to 3 yuan. 1g5 of 5 yuan's roe sauce on the market is a fake made of kelp, although the taste is almost the same as roe sauce.
The problem is that the symbol that the Yangtze sturgeon has been declared extinct in the wild is that it has no signs of natural reproduction since 2. According to the estimated life span of the Yangtze sturgeon, even if the last batch of naturally propagated Yangtze sturgeons were not overfished (before the fishing ban) or destroyed by water pollution, they basically died, and the definition of wild extinction is more accurate.
In order to change the state of extinction in the wild, it is necessary to rebuild the wild population through proliferation and release, and the symbol of rebuilding the wild population is that the artificially bred individuals can be self-sufficient and independent in the wild. But at present, it is obvious that this achievement has not been completed. If not, it has been released to hundreds of thousands.
Fourth, it is reasonable to say that the Yangtze sturgeon should not be too difficult to see. As for catching one, it will become a big news. What's more, the Yangtze sturgeon needs to go to a specific spawning ground to breed, and this spawning ground can be confirmed to be destroyed.
We have not found any other spawning ground, and it is basically hopeless to breed in the wild. In other words, if the artificial reproduction is released and stopped, it will be gone immediately. Therefore, I'm afraid I'll have to wear this extinct hat in the wild.
Three research groups of the Yangtze River Fisheries Research Institute participated in the "Battle": the reproductive physiology group in the breeding room was responsible for the artificial reproduction of Chinese sturgeon under Gezhouba; Nutritional bait group, responsible for the biological culture of live bait for juvenile fish and the cultivation of juvenile fish; The resource group in the resource room is responsible for the investigation of resources and spawning grounds. From 198s, researchers of Yangtze River Fisheries Research Institute used the wild parent fish of Chinese sturgeon to breed the first generation. By 29, the first generation successfully bred the second generation, and the full artificial breeding system of Chinese sturgeon was completely established. In 216, the Fishery Supervision and Administration Office of the Yangtze River Basin of the Ministry of Agriculture (now the Ministry of Agriculture and Rural Affairs) set up a project to carry out the "National General Survey of Artificial Breeding of Chinese Sturgeon".
It took four years, and the survey results showed that the artificial breeding population of Chinese sturgeon was mainly concentrated in 25 artificial breeding bases (including national scientific research institutes, research institutes of central enterprises, breeding bases in protected areas, breeding enterprises and aquariums). According to statistics, there were 3,91 Chinese sturgeons, including 2,132 in Hubei. After the successful artificial propagation of Amur sturgeon, the staff will select individuals with strong wildness and good physical fitness for wild propagation and release, and have accumulated 34, for many years. In 221, Jingzhou City, Hubei Province released 1 second-generation sturgeons. In 22, more than 1,4 Yangtze sturgeons were released in the proliferation and release activities of Luzhou City in 22. According to incomplete statistics, from 218 to now, about 6 Yangtze sturgeon gonads have matured and nearly 34, young fish have been released.