Species (Sprattus sprattus) of edible fish in the herring family. Sprats are silver marine fishes that form enormous schools in western European waters. Less than 6 in. (15 cm) long, they are especially valuable for canning as sardines. They are eaten fresh, tinned in oil, pickled, or smoked. The term also refers to a small or young herring or similar fish (e.g., anchovy).