The cactus roach (Rutilus virgo) is a species of fish in the family Cyprinidae, native to the basin of the Danube River upstream of the Iron Gate, very numerous in the Sava basin. It is also recorded in the Ukrainian Zakarpattian region. This freshwater fish is up to long,[1] averaging .
This species spawns between March and May, over gravel or submerged plants. Males develop massive nuptial tubercles with two lines of large tubercles on each side of the head above the eyes, almost joined into ridges. Those on the body unorganised, and occupying most of scaled area. Females lack these sexual ornaments. The size and complexity of tubercle growth, which are unusual in European fishes, has led to the common name.