Ronald the serial muncher...

[JohnHuff]

Ronald is a new koi to our pond. Had him for about a week, had been shy the first day or two but mixing in well now. Just tonight saw that he seems to be munching on other fishes' fins. At first thought it was humorous but then saw that 1-2 other fish appeared to have fin damage.

One fish had a dorsal fin that seemed different and then I saw Ronald swim up behind his fin and try to munch it. I know this isn't mating behavior because he's not nosing at their cloaca. I've had my pond for about 10 years and this is the first time I've seen it happen.

Is this normal? Are some fish bullies? Should Ronald be going back to the store? Thanks for any insights into this.

 

[fishin4cars]

Bullie is a posibility, Is this a Koi, Goldfish or other. Very rare for Goldfish to behave in this manner, koi a little more common but still pretty rare. Golden Orfs can get pretty nippy as well as a few other fish that are kept by some pond keepers. I would at least watch closely for the next few days.

 

[JohnHuff]

Ronald is a koi, okey doke.

 

[DrCase]

He sounds like a trouble maker

 

[HARO]

Are you sure the other koi don't have fin rot or some other problem? I have observed fish nibble at fins that are already affected with some other problem.
John

 

[JohnHuff]

@HARO, Ronald is the only one munching and except for the place that Ronald has munched, the other fins on the same fish looks fine. It doesn't look like fin rot, and the other fishes look healthy. I just looked it up and it also appears that aggressive biting fish can make other fish susceptible to fin rot so if it looks like Ronald is continuing to bite, then he's not welcome here.

 

[j.w]

Bad Ronald...................I think that there was a t.v movie by that same name and it didn't turn out well for Ronald or whoever he was around! Ha Ha I found it:

 

[JohnHuff]

It's not turning out well for Ronald. I observed him for 1/2 hour this morning and he likes to bump and try to bite the other fish. I'm pretty sure that the damage done to Goldilock's dorsal fin is from him bumping against it from the back. I just can't imagine living in a pond with another fish that's trying to bump and grind against me all day and night. I've already called the fish store and they will take him back. I just hope they won't euthanize him.

Nonetheless I will be keeping an eye out on fin health in the pond. Goldilocks is a butterfly koi so I think it's especially bad because he has flowing fins that's attractive for a serial muncher.

 

[koiguy1969]

i loved that movie as a kid.....BAD RONALD.....WOW that brings back memories.