Searching for the "mascot" of the Lo River.

baophutho.vn The Lo River – a historical river steeped in legends. Besides its cultural value, the Lo River also boasts many precious products such as the Chiên, Quất, Lăng, and Ngạnh fish, especially the Anh Vũ fish – a rare species considered the "sacred animal" of the river. Legend says the Anh Vũ fish appeared in Vietnam around 2000 BC. Around the 14th century, during the reign of the 3rd Hung King, a fisherman caught an Anh Vũ fish in the Lo River area and presented it to the king. Its unusual appearance and delicious taste led the king to consider it a rare and precious fish. From then on, anyone who caught an Anh Vũ fish had to offer it to the king. The Đại Nam Nhất Thống Chí also records: "The Anh Vũ fish, also known as Giả Ngư, lives at the confluence of the Bạch Hạc River. It only appears annually during the cold season. The fish is very delicious and nutritious. It is no longer found downstream from the Bạch Hạc River." More specifically, in the Geographical Gazetteer, Nguyen Trai also wrote: "The Anh Vu fish is used as an offering to the gods..."

Source: https://baophutho.vn/phong-vi-dat-to/di-tim-linh-vat-song-lo/195597.htm