I have a koi pond at home.  Koi are considered colored varieties of Amur carp.
Oh interesting, Ive been actually wanting to get some for my small pond, Are they hard to take care of? 
Not really.  They are coldwater fish and they have a great ability to adapt to many different climates. 
Oh very nice, I suppose they would be a good fish choice then, How big do they generally get? 
Koi are pretty small, similar to goldfish.  They stand out due to their patterning and coloration.
Oh got ya, I have seen them before at our local park, there is a giant pond there, How long do they love for? 
I really do not know.  I do know that they originated in East Asia back in 5th century BC.
Sorry I meant to say live but I know they are quite popular in Japan, Any other cool koi facts that I should know? 
The butterly koi is a specialized fish that is elongated.