In contrast to the flounder, its eyes are on the left side of its body, and the flounder are nocturnal predators, but its habits are more violent and voracious than those of the flounder, and it is known as the "robber of the sea". They have sharp teeth, and not only guard their prey intently, but also leap out suddenly to hunt when the prey is approaching.

The side with eyes is dark gray or patchy (another difference from flounder).

Mainly found in tropical and temperate waters (also different from flounder). It is mainly found in the Min River, the Yangtze River and its tributaries.