Rhodeus is a genus of cyprinid fish, consisting of 22 species called bitterlings. The scientific name is derived from the Greek word rhodeos, meaning "rose". Most species in the genus are restricted to Asia, but two species are found in Europe (R. amarus and R. meridionalis). In 1936, the bitterling was thought to respond to hormones in a pregnant woman's urine, but the work was later discredited.