Last week MJ gave me some Black Japanese Trapdoor Sails. Quite a mouthful for such a little thing. Actually, it is about an inch long and will grow up to three inches. I here they like to eat algae; and my little pond has some for them.
This is a picture of my Koi from last year when I bought them.
Now look at them. They are only one year old. I am afraid they might out grow my pond. We'll see.
In the mean time, they'll just keep cruising around.