Origin:
According to ancient legend, the Yellow River carp will change into a dragon when it jumps over Longmen (Yumenkou, Hejin City, Shanxi Province). "As the saying goes, a fish jumps into the dragon's gate, but it's only a carp." "Creeping Fan Objects" by Li Yuan of Qing Dynasty: "Carp ... every year, the yellow man Ji Chun climbs the Longmen Mountain upstream, and the sky fire burns its tail from behind, then it turns into a dragon." Later, the metaphor of "carp jumping at the dragon gate" was used to describe things such as promotion and promotion. Later, it was used as a metaphor to go against the current; Make progress. As the saying goes, "Carp jumps at the dragon gate", which is a metaphor for carp's habit of diving. Carp and many other fish like diving. Some fish jump very high. For example, there is a fish called "Jumping Fish", which can jump four to five meters above the water, and can be said to be the "high jump champion" among fish.
The Chronicle of Bamboo Books is the work of the historian of Wei at the end of the Warring States Period, which shows that the fairy tale of "yue longmen the Carp" was not formed at that time. Most of the records of "fish turning into dragons" come from Han dynasty classics, so the fairy tale was formed in the early years of the Western Han Dynasty, which may be related to the strengthening of the concept of dragon worship in the early Han Dynasty.