What kind of running water is called "goldfish water" in Feng Shui?

What kind of running water is called "goldfish water" in Feng Shui? -I haven't observed it. The description in the Feng Shui book is: "All fish breathe, and water enters the gills from the mouth; Only goldfish can breathe, and water enters and exits from the gills. " It can be inferred from the above statement that there is running water on both sides of the terrain where the acupoints are located, and then the goldfish flows to the middle point "; That is, the characteristics of double water confluence.

I can't find a suitable picture, so I hope I can draw inferences from others.