The international definition of deep sea is 1000 m water depth. Duobao fish is a kind of flounder, belonging to Scophthalmus of Scophthalmus. It is naturally distributed along the Atlantic Ocean and the eastern European coast, and is commonly found in sandy, gravel or mixed-bed waters with a water depth of 20 ~ 70m in the North Sea and Baltic Sea. So it does not belong to deep-sea fish.
Duobao fish grows rapidly, and it only takes 10 ~ 12 months from spawning and hatching to selling commercial fish (0.8 ~ 1 kg). High economic value, high bait conversion rate, strong disease resistance and low oxygen consumption, suitable for high-density culture. Therefore, most of the products currently seen on the market are farmed products.