Flatfish are a type of fish. There are several different kinds of flatfish. Some of them are fished commercially, like flounder, sole, turbot, plaice, and halibut.

All flatfish are rather flat, and are ray-finned fish. During their evolution, their eyes have moved so that they are on the same side, which the fish keeps uppermost. They swim like this, and can hide in the sand waiting for prey on the ocean floor. They have a capacity for dynamic camouflage, which is under nervous control, and can change in 'real time' to match their background.

Cod is the common name for the demersal fish genus Gadus, belonging to the family Gadidae. The two most common species of cod are the Atlantic cod (Gadus morhua), which lives in the colder waters and deeper sea regions throughout the North Atlantic, and the Pacific cod (Gadus macrocephalus), found in both eastern and western regions of the northern Pacific.

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