Im not making it less common but the Common Carp is a freshwater fish that can easily be kept in any aquarium, though it will become 75cm at least which would then require it to be the size of your living room, unless youre living in a deserted castle like me ofcourse, anyway, its a great gamefish too, my record is 92cm in length and 35 pounds in weight. Compared to variants with less scales, i.e. mirror carp, this one is much more resistant to diseases and parasites, but its looks are quite ehm common.