Rudd is very sensitive to water pollution. When small and young, it closely resembles roach. It can grow up to 45 centimeters and age up to 15 to 20 years. Although it needs meat to grow well, rudd is mostly vegetarian. Its main diet consists of aquatic plants, such as pondwee, spiked water-milfoil, waterweed, diatoms and filamentous algae.