It's very hard from the pics but I think I may can help some. If it's solid brown and fully scaled it would be a Chagoi (usually known as the calming koi as they will calm the rest of the herd and become quite friendly, But they do get quite large.) If it has smooth skin or far larger scales than normal scaled koi then it would be called a Saragoi. Now if it's black and has a brwon or red belly it would be called a Karasu, and if it's solid black or deep chocolate colored with white edging on the fin then it would be called a Hajiro. If I had to guess from the pic I would say probably Chagoi but without a better pic that's about the best I can do.