Common rudd

The common rudd (Scardinius erythrophthalmus) is a bentho-pelagic freshwater ray-finned fish belonging to the family Leuciscidae. This species is widely spread in Europe and central Asia, around the basins of the North, Baltic, Black, Caspian and Aral seas.

Habitat

Rudd prefer clear waters rich in plants. They also feed on aquatic vegetation when the temperature exceeds 18 °C. They hunt for living prey in the upper levels. They prefer mesotrophic waters, while the roach is sometimes found together with the perch in waters that are nutrient poor. Rudd appear to prefer non-acidic water.

It prefers shallow weedy areas in lakes and river backwaters, where mature females lay up to 200,000 eggs on submerged vegetation. Young rudd eat zooplankton, aquatic insects, and occasionally other small fish. Mature rudd, which are about 18" in length and weigh about 3 pounds, eat mostly aquatic vegetation. The rudd can consume up to 40% of their body weight in vegetation per day, as much as 80% of which is discharged as waste, releasing nutrients into the water column. They can tolerate a wide range of temperatures and water conditions, including eutrophic or polluted waters. In the laboratory rudd readily hybridize with the U.S. golden shiner (Notemigonus crysoleucas). They come in both silver and gold, and are sometimes sold as pond ornamentals.

Maximum lifespan has been reported as 17 years. Sexual maturity has been reported at 2–3 years.