Pacu fin nipping

[OTp1144]

So I have two 18" RBP in a 300g (8x2.5x2) that for the most part until recently have been getting along wonderfully with their tank mates. (channel cat, RTC, 2 P. Gibbiceps, indo dat, 2 oscars, ornate bichir). However, in the last week or so, they have really started to nip at the ornate. To the point I had to take her out of the tank because her tail fin is shredded.

Are they simply too big for the tank or is it a different issue? I've heard they become more aggressive when fed meatier foods, and this tank does get a lot of smelt because of the catfish. They do also get a wide variety of other foods - carrots, grapes, koi pellets, hikari cichlid gold, massivore, broccoli, etc.)

I do have a 4600g pond I can put them in, but I'm hesitant about doing so because it's currently overstocked with koi and goldfish (different issue i need to deal with) and many are butterfly and I REALLY don't want the pacu nipping at the fins or whiskers of the koi...

 

[OTp1144]

Bump. Anyone? Will these guys start nipping my koi and goldfish?

 

[Wailua Boy]

I bet in a 4600g enclosure(as long as temp. and water parameters are acceptable), they should cohabitate. Hard to say for certain, as they do have their own personalities/behaviors. They will probably keep your GF population in check. IME, keep them well fed and they tend to be fairly mild mannered but I have heard stories of aggressive RBP's. I usually recommend at least 600g for RBP's.

 

[OTp1144]

Thanks. Guess I'll give it a shot. I'm hoping they'll be intimidated by the larger fish and chill out

 

[Wailua Boy]

I would just watch for aggression but I have had friends who have mixed koi and pacu with no problems. I would be more concerned with fancy GF...With a over populated pond, this is probably just what you need.

 

[Drstrangelove]

Are they simply too big for the tank or is it a different issue? I've heard they become more aggressive when fed meatier foods, and this tank does get a lot of smelt because of the catfish. They do also get a wide variety of other foods - carrots, grapes, koi pellets, hikari cichlid gold, massivore, broccoli, etc.)

1) many pacu are 95%+ vegetarians.
2) any fish may exhibit unusual behavior when crowded. A 300g tank is far too small for one pacu. It's clearly so for 2 of them, much less so when one also has a channel cat, a RTC, 2 P. Gibbiceps, an indo dat, 2 oscars, and an ornate bichir.

What was your plan before this?

 

[OTp1144]

Oh they were all always going to get put in the pond, but I was going to wait at least a bit longer. Guess my timeline sped up a bit.lol

 

[Drstrangelove]

Oh they were all always going to get put in the pond, but I was going to wait at least a bit longer. Guess my timeline sped up a bit.lol

Well that makes perfect sense. I think you've just raised them a bit better than you expected and they grew a bit faster. The actual cause of the behavior could be a few other things besides over crowding or diet, but it could be just as you said: your timeline is speeding up.

 

[OTp1144]

I actually got them a couple months ago at pretty much the same size they are now. I just figured I'd have a bit more time. But hey, they made it through the night no problems!