The herring is long, and the grass carp is bluish-black, but it is thicker and rounder than the herring, and its back is black. The crucian carp is round and flat with large scales, and its back is black and its abdomen is white and clear. Silver carp is long and round, with small and dense scales. Carp has a big belly, round and sad scales, but its belly is mostly yellow or red. The above fish head is smaller than the fish body. Bighead bighead and small tail. These are the most common freshwater fish.