The Chinese sturgeon (Acipenser sinensis; ) is a critically endangered member of the family Acipenseridae in the order Acipenseriformes. Historically, this anadromous fish was found in China, Japan, and the Korean Peninsula, but it has been extirpated from most regions due to habitat loss and overfishing. It is strictly protected by the Chinese government, named a "national treasure" much like its mammalian counterpart, the giant panda. China has several conservation programmes, including reserves specifically aimed at this species and restocking through release of juveniles in the Yangtze River. Physical appearance Sturgeon are comparatively basal species of fish, whose earliest fossils date back to the Cretaceous period. They are best-known members of the bony fish taxon Chondrostei, a group of bony fishes that have cartilaginous skeletons superficially similar to the skeletons seen in the unrelated chondrichthyan fishes. In Qing dynasty Chinese cuisine, its meat and cartilaginous skeleton was often cooked and served together, and considered a delicacy. Adult Chinese sturgeon can range between in total length, and weigh between , ranking them among the largest sturgeon in the world. Its head is acuminate, with the mouth under its jaw. Lifecycle Most sturgeon spawn in fresh water and migrate to salt water to mature. The Chinese sturgeon can be considered a large freshwater fish, although it spends part of its lifecycle in seawater, like the salmon, except Chinese sturgeon spawn multiple times throughout their lives. The Chinese sturgeon has a habit of upstream migration; it dwells along the coasts of China's eastern areas and migrates back up rivers for propagation upon reaching sexual maturity. It has the longest migration of any sturgeon in the world, and once migrated more than up the Yangtze. The sturgeon may breed three or four times during its life, and a female sturgeon can carry in excess of a million eggs in one cycle, which are released for external fertilisation when mature. The survival rate of hatchings is estimated to be less than 1%. The Chinese Sturgeon will migrate from the mouth of the Yangtze River to the spawning ground and the female Acipenser Sinensis will stay there for a year to prepare for spawning activities, and then all Acipenser Sinensis will migrate to the lower middle and upper layers for spawning activities and female Acipenser Sinensis leave earlier than male Acipenser Sinensis. Changes in the water temperature of the Yangtze River will delay the spawning time