Ghost carp, Cyprinus carpio
Ghost carp are produced by mating Koi with Mirror carp. Many are bred in the UK, so they’re often hardier than Koi and already used to British weather. They range in colour from pale cream, through to black with varying amounts of orange or metallic flecking on the scales. They’re not as attractive, or as easily seen as Koi, but they are much cheaper.
Ghost Koi:
Ghost koi are a mix of a platinum ogon koi and a common river carp. They have a shadow or skull-shaped patch on their backs and/or head over "wild colored" skin. These dark, "ugly" koi were developed in the UK and are more hardy than ordinary koi.