A freshwater fish species, Stizostedion vitreum, now classified as Sander vitreus, belonging to the family Percidae and distributed across the rivers and lakes of North America. It is named for its large, glassy, light-gathering eyes, an adaptation to low-light feeding. Its flesh is highly esteemed for its lean, flaky texture and mild, sweet flavour, making it one of the continent’s most prized table fish and a mainstay of Great Lakes fisheries and the Friday fish fry tradition. It is cultured in some parts of North America, and it is marketed fresh and frozen. Freshness and careful cold-chain handling protect its delicate texture, and both commercial and recreational harvests are managed to keep stocks healthy.