koi jump out of pond

Question
I live in Sacramento, Ca. I have had this koi pond for over two year. Just tonight I checked the pond and saw one of my 5 kois was missing. I glanced over to the edge of the pond and found him/her laying on the ground. Body was bleeding from the side it was laying on. I noticed some scratches at the bleeding site but other than that fish looked ok. I put it back and it swam immediately to the bottom of the pond and joined that other fish. Can you tell me why this happened. I do not beleive any animal went in to get it as I would have seen claw or bite marks and the fish probably would be torn up pritty bad. It was not.

The water is crystal clear. The only thing I have treated the water with on a regular basis is Algifix as we had a problem this past summer with string algee. It cured the algee problem and the bottel said to continue to dose pond weekly. I have followed that routine weekly since this past summer. Could that be stressing the fish out?

Your advice on this matter is greatly appreciated.

Bob Solimena

Answer
Hi Bob,
Thanx for your question.  Koi are notorious jumpers.  They are active swimmers and easily excitable.  It wasn't anything you did, they just like to jump and I have heard or and seen them beach themselves before.  You are fortunate that you were able to save the fish.  Another thing is an animal may have caught the fish and brought it out of the water just before you stumbled upon it.  An animal like a cat or a raccoon can do this without too much damage to the fish other than a few scratches.  If you are hand-feeding your fish one of the hazards is the fish cannot differentiate between the human host and a predatory animal.  There's really not much you can do and often the fish will beach itself and then pop itself back into the water.  I hope this helps.
Tom