The skin contains a pigment called "red pigment". The red-striped mandarin fish is a tropical freshwater fish, and its skin contains a pigment called "red pigment". Red pigment is a macromolecular natural organic pigment derived from flavin and carotene, which can appear in red, orange, yellow and other colors. On the body surface of the red-striped mandarin fish, this red pigment is concentrated on the sides and abdomen, forming bright red spots or lines. So the red-striped mandarin fish will be red. Red-striped mandarin fish, also known as red tiger auspicious fish or red tiger pufferfish, is an ornamental freshwater fish belonging to the family Pufferidae, native to the Amazon Basin of South America. They usually have plump and strong bodies with bright red, orange, black and other colors of stripes or spots, which are very beautiful. Red-striped mandarin fish is a carnivorous fish that can eat fish, shrimp, shellfish, insects and other foods.