to the largest rivers and lakes. It feeds at any depth, although its preferred food sources tend to be in shallower water. It tolerates organic pollution and is one of the last species to disappear in polluted waters; it is also often the most numerous cyprinid in nutrient-poor waters. It also tolerates brackish water. Roach survive in temperatures from close to freezing up to around . In most parts of its distribution, it is the most numerous fish, but it can be surpassed by the common bream in biomass in water bodies with high turbidity and sparse vegetation. The roach is a shoaling fish and is not very migratory with the exception of the oceangoing subspecies. In the cold season, they migrate to feed in deeper waters, whereas they prefer to feed near the surface during warmer weather. Roach mostly inhabit freshwater ecosystems that are somewhat vegetated, because larval and young fish are protected by the vegetation and the mature fish can use it for food. The common roach eats a wide range of foods, from plant material, bottom-dwelling (benthic) invertebrates, to worms and maggots. Young fish feed mainly on plankton, until they are of a size to use a wider diet. Roach can adapt to environments where invertebrates are scarce by slowing their growth, maintaining slender body shapes, and maturing early. Roach may live for 15 years or more. Reproduction The spawning season is generally from March to June, with some variation due to spawning being triggered by the rising of water temperature during spring and summer. Roach generally spawn at the same location each year. Large males form schools, which females enter. Males trail the females and fertilize their eggs. Their behaviour is rough and the fish often jump out of the water. A female can lay up to 100,000 eggs. When the pH of the water is below 5.5, the roach cannot reproduce successfully. See also Caspian roach - related Caspian Sea species or subspecies, Rutilus caspicus References External links Family Cyprinidae Australian Society for Fish Biology All About Roach - Article Rutilus Freshwater fish of Europe Fish of Central Asia Fish described in 1758 Taxa named by Carl Linnaeus