My large white Koi jumped straight up in the air about 3 feet and then plopped back into the water last week while I was doing some cleaning. I think there was some mating going on as there were fish chasing other fish. In the 12 years I've kept a pond I've always had one or two jumpers but never out of the pond--that is scary. I do have a lot of vegetation surrounding the pond and planting shelves and have had to help a fish or two back in from the reeds when mating got too crazy.

My large koi jumps sometimes. The times I've noticed is because it tries to get around some of the other fish that seem to always be around it or clashing into it..My kids tell me it jumps too..I just know mine can be a little hyper. I have a lot to learn..And I am interested on seeing what others have to say about it.

Hi Guys
Koi will not normally jump out of the water. They will if they are stressed or attempting to escape a predator. For instance, when cleaning a pond and putting fish in a new environment in which they feel threatened.
My point is, there is a very good possibility that the reason your koi are jumping is due to irritation. Take notice if your koi are "flashing". Flashing- is when the fish will attempt to scrape its side on the bottom or on a rock. The scales on the opposite side reflex in the sunlight and looks like a flash. Koi will flash or jump when parasites are attached to their side. The flashing or jumping is an attempt for them to scratch an itch. This is not normal. Prolonged flashing will cause damage to the fish. Look for ulcers or raw areas on the fish.
I hope this helps guys...Craig