Perch is the firm, white, sweet-fleshed freshwater fish of the genus Perca — above all the European perch (Perca fluviatilis), the olive-green, dark-barred, red-finned fish of the continent's lakes and slow rivers. Its lean, fine-flaked flesh is mild and gently sweet, holding together cleanly in the pan, and it is the fish behind two great traditions: the delicate filets de perche of the Alpine lakes and the lake-perch fish fries of the North American Great Lakes.