Rhodeus sericeus, length: 5-8 cm (maximum 11 cm)
Amur Bitterling lives in quiet regions of lower parts of rivers, old river beds, river broads, bays with muddy river bottom and overgrown lakes. Bitterlings live in a school of fish consisting of a dozen or so members, and they often tend to join to schools of other fish species living in the water basin.
The fish characterises with grey and green chine, grey and silver sides, and white belly often with a shade of pink. Its scales has got dark grey edge, what makes a kind of netting pattern. In the back part of its body, there is blue and green stripe in the shape of narrow triangle with its basis located in the middle part of tail caudation. Dorsal and anal fins are grey, but a caudal fin , as well as pectoral and pelvic fins are red or flashy orange.
Amur Bitterling changes its colour during its spawning time.
The fish feeds on phytoplankton.
In Poland, this species is under strict protection.