Tradition / Region: China (Jin dynasty and later traditions)
Alternate Names: Black Fish, River Spirit
Category: Fish / river spirit
The Myth
Xuanyu is a mythical black fish recorded in ancient Chinese texts. Its origin is closely tied to the great flood myths of early China. According to tradition, Gun, who was ordered by Yao to control the floods, failed in his task after nine years. In despair, Gun drowned himself in a place called Yuyuan. After sinking into the waters, he transformed into a Xuanyu.
As a Xuanyu, Gun appeared as a vast black fish. It was said to rise from the water at times, shaking its whiskers and scales as it floated across the waves. Those who witnessed it believed they were seeing a river spirit. During seasonal rites and sacrificial ceremonies, black fish and dragons were often seen leaping from the water, filling observers with awe and fear.
Other records describe the Xuanyu as an enormous creature, said to reach a thousand feet in length. One account tells of such a black fish appearing near the sea, dying there, and lying between river and ocean. Sages regarded the black fish as a divine being and combined the character xuan (dark, mysterious) with yu (fish) to name it Xuanyu.
Additional traditions state that another figure, Shen Yuyuan, also transformed into a black fish after death. In these accounts, the Xuanyu was worshipped as a powerful water spirit. Shrines were built in its honor near mountains and coastlines, and sacrifices were offered to it throughout the four seasons. People claimed that when the Xuanyu manifested its power, the shallow sea would rise and water would spray upward for hundreds of feet.
Across these tellings, the Xuanyu appears as a transformed being born of death and water, moving between river and sea, feared and revered as a divine black fish whose presence revealed the lingering power of those who failed, perished, and yet endured within the waters.