Question
Our koi pond is one year old.  We have 2 koi, 1 Oranda, 1 Black Moor, 1 Calico fantail, 2 Shubunkin.  This morning I noticed that the fish were ganging up on the Oranda and one of the shubunkin.  They were trying to push the Oranda out of the water and would not let it swim freely and at times like it was attacking it and also one of the shubunkin.  What could be causing this?  We have removed the Oranda put it in a bucket with pond water.  Are they trying to kill them?  We tested the pond water and it seems okay.

Answer
Um, welcome to the world of goldfish spawning!  When people say their goldfish are acting "crazy," it's usually breeding activity.  It sounds like the Oranda and shubunkin are female, and the others were trying to spawn with them.  Goldfish don't need an excuse to pester each other but it sounds like normal spawning to me.  Spawning can be deadly, mostly for females who get beat up.  Your fancy goldfish can't take the spawnings as easily as single-tailed goldfish like the shubunkins.  My page on goldfish breeding and more is at http://www.fishpondinfo.com/gfish3.htm
Good luck!

Robyn