Rutilus virgo (Heckel 1852)

Distinguished from its congeners in Danube drainage by having the following unique characters: peritoneum black; anal fin usually with 11-12½ branched rays; and breeding males with two horizontal rows of large tubercles on side of head above eye, usually more or less fused into a continuous ridge (tubercles white in ethanol); and tubercles on body massive, occupying most of scale area. Can be further separated from other species of the genus in Danube drainage by the combination of the following characters: 44-46 scales along lateral line; mouth inferior; snout blunt; body laterally compressed, maximum body width about 50% of body depth; body greenish to bluish brown; iris silvery (Ref. 59043).

Inhabits medium sized to large rivers. Spawns in fast-flowing water of riffles over gravel or submerged plants. Attains a maximum size of about 40 cm SL (Ref. 59043).

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 55 cm long.