Common roach (Rutilus rutilus) is a freshwater fish of fresh and brackish waters of Europe and Siberia. Body length 30-35 cm, weight up to 800 g. It is a gregarious fish. Spawning in May-June. It lays eggs on vegetation. It feeds mainly on invertebrates and algae. It is an object of commercial and recreational fishing. It has many subspecies; some of them have their own names. Rutilus caspicus (Rutilus caspicus) is a subspecies of the common roach in the Caspian Sea, Rutilus heckelii in the Black Sea and the Sea of Azov, Rutilus aralensis in the Aral Sea, and Rutilus lacustris in Siberian waters.

Common roach is found throughout Europe east of southern England and the Pyrenees and north of the Alps; in rivers and lakes of Siberia, in the basins of the Caspian and Aral seas. Common roach differs from its closest species in having unnotched and located on each side in a row of pharyngeal teeth (5-6 on each side), relatively large scales (40-45 scales in the lateral line), a mouth at the end of the snout and the position of the beginning of the dorsal fin above the bases of the pelvic fins. The back is blackish, with a blue or green tint, sides and belly silver, dorsal and caudal fins greenish gray with a reddish tint, pectoral - yellowish, pelvic and anal - red, iris yellow with a red spot. There are also specimens with eyes and fins of yellow color, with golden scales, with a reddish tint on the sides and back. 

The easiest way to distinguish Common roach from redfish is by the color of the eyes: the former have blood-red eyes, while the latter have orange eyes with a red spot at the top. Another difference is the number of soft feathers on the dorsal fin: the roach has 10-12 of them, while the redfin has 8-9. Sometimes there are hybrid forms of these fish, possessing features of both species. Keeps usually in flocks in places with a weak current under the protection of snags, hanging tree branches or aquatic vegetation. At the same time in a flock of medium and small fish can be and single large specimens. Small and medium-sized fish are not fearful. Maximum body length - over 50 cm, weight - up to 3 kg, maximum life expectancy - 21 years. The world record is considered a national record of the former GDR - Common roach weighing 2.58 kg was caught and recorded there. Common roach weighing 2.55 kg caught in Finland in 1939 is close to the record (sometimes mistakenly considered a world record).