Aggressive Rainbow Fish

[OhNeil1969]

I've got a problem with one of my boesemani rainbows. I've 2 boesemani and 2 australian rainbows. The largest of the 4 is ultra-aggressive to the other rainbows including the other boesemani. Has anyone had any experience with aggressive rainbows?

Other tank mates in my 60 gallon tank include:
4 marbled angels;
2 punctatus cory cats;
2 peppered cory cats;
2 red dwarf gourami;
5 harlequin rasboras.

Water change was performed yesterday. Prior to change water parameters were: 0 ppm ammonia, 0 ppm nitrItes, 10 ppm nitrAtes.

I really like this particular boesemani as it's the most colorful, but I don't want him stressing the others into illness. Could it be a male/female ratio issue like with male mollies? If so, how do you determine the sex of a rainbow? Any info will be greatly appreciated. His behavior seems to be opposite of everything I'd read about the species prior to making the purchase.

BTW; he only bothers the other rainbows. He doesn't interact with any of the other fish.

 

[Jason7894561230]

I think removing him is sometimes the best thing you can do. Exchanging it for another one is the best option for is to get a different one.

 

[OhNeil1969]

I think removing him is sometimes the best thing you can do. Exchanging it for another one is the best option for is to get a different one.

Thanks Jason;

I hoping there might be some explanation for his behavior that I can correct. In fact, I was hoping to use it as an excuse to get some more boesemani. But, in the end you're right. I'm going to keep an eye on him over the weekend and if I can't find a solution and there is no change in his behavior then I'll take him back.

 

[capisderf]

I wonder if these fish get more aggressive as they get older. I seem to remember reading that in my fish book for some fish types. Maybe he is an older one.

 

[OhNeil1969]

When researching the boesemani I read that they prefer a school of 5 or more. I was hoping that they would "bond" with the australian rainbows and they could all serve as a school. There are times when the aggressive boesemani would appear to be schooling with the australians, but never with the other boesemani (which is the smallest of them all). Could it be that I need to add more boesemani? Was it foolish of me to think the 2 different types of rainbows would school? I was really trying to spread the cost around as the boesemani were 5x more expensive than the others.

 

[OhNeil1969]

I just went to check on my tanks. While there I was able to take some pictures of the aggressive boesemani schooling with the 2 australian rainbows. Yet, right before I started this thread he was chasing 1 of the australians. The other boesemani, however, is hiding in the corner.

Here are a couple of pictures:

 

[Jason7894561230]

I think that it may be male to female thing also as he is maturing he could be sexually active and is breeding maybe. And go the Australian Rainbows (im from Australia)