Can Koi Be Agressive?

[star4]

This is going to sound silly but one of my koi (about 6") keeps, what it looks like, sucking at the others and really annoying them. I am getting very concerned now as I lost a 9" koi the other day really suddenly for no aparant reason.

The koi that is doing the sucking is going around the gills of the others and trying to get its nose under the gill covers.

 

[mixmaster jay]

yep if they are breeding normally

but ive not heard of what your describing star

 

[star4]

Hi Jay, they are too young to breed, not even 2 yet. I have been searching the net and even phoned the lfs that specialise in Koi, no one seems to have seen this behaviour either?. It was thursday when I lost the golden koi, he was absolutely fine apart from this little koi "nosing" round his head, I took the dog to the vets, got back and his was belly up?

I have been watching closely now, this one is being a real nuisance and its starting to stress the others, but its mainly picking on the big female now. The golden koi was male. I think I am going to take it out and stick it in a tank or something.

Never seen anything like this !!!!!!!!!

 

[mixmaster jay]

how strange

 

[saph.st24]

my koi became aggressive to the goldies when they where in the tank but they arent in the pond they live happily until breeding
its not age that counts its size koi 10in and above will breed and temps of 18plus for a week or more will cause it too

 

[star4]

Hi Saph, I agree with you I doubt its breeding agression because of the age/size. I split him from the others for a couple of hours then put him back, seems to have stopped doing it now? really weird