agressive koi

[Cdsdave]

Hi guys. Hope your winter was good!! I'm glad it's spring though. Time to get the pond in order.

Tonight I came home and found my green glo fish missing. He's been a loner since I got him about two months ago, but lately he's been hiding in the "house". I took the house out to see if he passed and floated up underneath. Not there. Not in the overflow or sump.

There are two other glo fish, three koi, and three goldfish. The biggest koi is about 6 inches, the rest of the fish are about 3-4 inches (glo fish about 1 inch). 65 gallon tank.

After I fed the fish I noticed big koi acting aggressive toward the others. Going after them nipping at their tails and being a bully. Could it be mating behavior? I just can't see how he could of eaten the glo fish. His mouth is big but not that big!! Aside from alien abduction though he must of!?

Thoughts?

Thanks

 

[Dave 54]

At 6" I doubt very much that this is mating behavour , are glofish and Koi even compatable in the same tank I dont really know but I doubt very much they would normally ever meet .
Koi towards fry can and are canniblistic but that normally fry smaller than 1"
In reality you wouldnt normally mix the two so I suggest it may well be an idea to remove and re-house the glofish in another tank .

Dave

 

[JohnHuff]

That is not mating behavior. Once you've seen it, you'll know what it is. This sounds like bullying. I dislike bullying. It's happened a couple of times over the years with a new fish and I have always returned it.

Again (like the last thread I wrote in), I always put myself in the position of the fish. In a pond or a tank you can't escape bullies. It's like living in the same house as one so bullies have to go.

 

[Cdsdave]

Thanks guys. The koi are going outside once the water warms up. The big guy has always been clumsy but gentle. Last night was the first time I ever seen him act that way. I watched him during the morning feeding and he was fine. At night I always soak their food in garlic juice for health reasons. I understand it can be like alcohol for them? Perhaps he had beer muscles going on? As I'm writing this I'm observing normal interaction among my friends.

Hopefully he just had a bad night

Thanks and take care!!

The face of my trouble maker

 

[dieselplower]

It would not surprise me to see a Koi eat a glofish. The are quite small. I guess you will know if his poop glows! hahahah jk!

 

[bettasngoldfish]

It's pretty normal for a larger fish to eat smaller ones. I don't consider it aggressive behavior at all.