Mauremys mutica, the most primitive and oldest species, is called "ancient stone turtle" among the people. It is believed that this kind of turtle, like the money turtle, has the geomantic function of helping breeders improve their wealth and career. The most striking feature of mauremys mutica is that it has a pair of bottom plates, and the bottom shell of the bottom plate is almost linear or blocky. Because it is very similar to the black floor of the three-line box turtle (but only the three-line box turtle is called the money turtle in the south of China), the people of Guangdong and Guangxi also call this black floor stone turtle the authentic money turtle, which is one of the reasons why some areas in the south collectively call mauremys mutica the "stone turtle" and "stone money". Most of these "ancient stone turtles" live on coastal islands drifting away from the mainland, or at the offshore end of the peninsula, and the number is rare. However, there are many private farms, and a large number of artificial breeding can already be carried out. It can be seen from the distribution of mauremys mutica that this species has strong adaptability to the food, water quality and climate environment of its habitat. Water turtles also have the characteristics of heat resistance, cold resistance and hunger and thirst resistance, and are extremely tenacious turtles.