Body size: Wild river fish are usually slender and small in size, because they need to feed independently in the wild, and their survival pressure is high. But farmed fish are generally fatter because they are fed regularly.
Body color: Wild river fish grows in flowing waters, and the water quality is clear, so its body surface color is relatively light, and its scales are thin and shiny. However, farmed fish live in still water, and there is silt at the bottom of the water, so the body surface color is darker and the scales are thicker.
Fat content: the fat content of wild river fish is relatively low, especially in abdominal cavity, because it may not be enough to eat every time. The excrement of farmed fish has a strong fishy smell, because the feed they feed is rich in nutrition and fat.