Merfolk

Merfolk, Merpeople, or simply Mer refers to humanoid creatures that live in deep waters like Mermaids, Sirens, Cecaelia etc.

Chinese rényú (人魚) stands for "merfolk", but in ancient geographical or natural historical tracts, the term referred to "human-fish" or "man-fish" purported to inhabit rivers or lakes in certain parts of China.

Certain fantastical types of "fish", generically referred to as renyu (人魚, "human-fish") are alleged to occur in various parts of China according to the Shan Hai Jing (Classic of Mountains and Seas, 4th century BC).

[5][1] It is recorded that the Mausoleum of the First Qin Emperor was illuminated with lamps fueled by the oil of the human-fish (renyu), whose flames were meant to last a very long time.

[6][7] In the Chinese Song Dynasty's supernatural tale collection Yijian Zhi (夷堅志), there are stories of sea sirens similar to those in other folklore.

However, when a fellow townsman arrived on the island and took the man back by boat, the woman cursed him, throwing their sons into the water in a fit of rage and yelling at him to leave.

[36][4] The illustration of the chiru from China may have influenced the legless, human-faced fish visualization of some of the ningyo in Japan, according to the hypothesis of Morihiko Fujisawa [ja].

[44][45] In the midst of the South Sea are the houses of the kău (Chinese: 鮫; pinyin: jiao; Wade–Giles: chiao[46]) people who dwell in the water like fish, but have not given up weaving at the loom.

Schafer equates this with sea silk, the rare fabric woven from byssus filaments produced by Pinna "pen shell" mollusks.

[57] Later accounts claim that Empress Suiko's regent Prince Shōtoku knew the creature to be a ningyo when one was presented to him by representatives of Ōmi.

[59] During the Kamakura Period, ningyo of the marine sort were frequently reported as washing ashore, and these were taken to be ominous signs usually prefiguring bloody battles.