The common dace (Leuciscus leuciscus), the dace or the Eurasian dace, is a fresh- or brackish-water fish belonging to the family Cyprinidae. It is an inhabitant of the rivers and streams of Europe north of the Alps as well as in Northern Asia. It is abundant in much of its range, and has also spread to Ireland where it is used as a bait fish. It will grow to a maximum length of 40 cm (1 ft 4 in), a maximum weight of 1 kg (2.2 lb), and may live for up to 16 years.
The common dace natively lives in a temperate climate and prefers water with a 6.0 to 8.0 pH and an ideal temperature range of 4 to 22 °C (39–72 °F). It prefers clear streams flowing over a gravelly bottom, and deep, still water, keeping close to the bottom in winter, but disporting itself near the surface in the sunshine of summer. It is preyed upon by the larger predaceous fishes of fresh waters, and owing to its silvery appearance is a favourite bait in pike angling. Its flesh is wholesome and is sometimes caught for food, but is not held in much estimation. While typically a freshwater fish, the dace enters brackish waters in the eastern Baltic Sea.
The dace is a lively, active fish, of gregarious habits, and exceedingly prolific, depositing its pale yellow eggs in the spring at the roots of aquatic plants or in the gravelly beds of the shallow, flowing streams it frequents. It poses a risk as a potential pest in some areas. In appearance it closely resembles the roach in both size and shape, with the head and back of a dusky blue color and the sides of a shining silvery aspect, with numerous dark lines running along the course of the scales. The ventral and anal fins are white, tinged with pale red, and the dorsal, pectoral and caudal tipped with black. The dace feeds on worms, insects, insect-larvae, snails, and also vegetable matter, albeit rarely.
In angling, the dace is known to respond to dry flies, particularly in the summer months.