Genus and morphology: Carassius auratus belongs to Carassius auratus and grass carp belongs to grass carp, which is the basic difference in taxonomy. Both have their own characteristics. Grass carp's body is relatively rounder and thicker, and it is shaped like a cylinder. Carassius auratus has a flat body and a flatter body shape. This morphological difference makes them have obvious differences in appearance.

2. Distribution and habits: Grass carp is mainly distributed in the Yangtze River and Pearl River systems and their attached lakes, reservoirs and ponds in China, mostly inhabiting rivers and lakes in plain areas, and generally inhabiting the middle and lower layers of water bodies and coastal areas with more aquatic plants. Carassius auratus is widely distributed in all parts of China, except the western plateau, mostly inhabiting lakes, rivers, canals and swamps, especially shallow lakes and ponds with lush aquatic plants. Crucian carp is an omnivorous fish with strong adaptability to hypoxia, while grass carp is herbivorous.

3. Nutrition and taste: Crucian carp and grass carp are also different in nutritional value and taste. The meat quality of crucian carp is considered more delicious and has higher nutritional value, especially the content of protein. In contrast, the nutritional value and taste of grass carp may be slightly inferior. This may be due to the different food sources and growing environment, resulting in differences in meat quality and nutritional components.