Mirror carp 
Between 2 and 4 cm
Mirror carp are a hardy, attractive variety of common carp (Cyprinus carpio), easily recognised by their irregular pattern of large, shiny scales. They are well suited to larger garden ponds, where they are active, long-lived fish that spend much of their time foraging along the bottom for insects, larvae and other natural foods. Mirror carp can grow to a substantial size, so they require a spacious, well-filtered and oxygenated pond with plenty of room to develop.