Aggressive towards other fish

I've been offered a free Bristlenose by another fishkeepr who described it as troublesome. They say it was harrassing their Goldfish because he wasn't getting enough food. He cornered one of the Goldfish trapped it under a rock and started feeding off it. I haven't seen it but they say it is definitely a bristlenose.

Is it possible?
My thinking is that something happened to the Goldfish and the Bristlenose was just scavenging

I'm sure your right, the Bristlenose is probably being outcompeted for the food, do you know what they were feeding

I have also heard of Bristlenoses that are kept with Discus feeding on the slime they produce to feed there young.

I think it's possible; other species have rouge individuals, why not BN? Certainly there could be feeding issues or problems with the health of the goldfish, but I have heard of BN attacking other fish before. Granted not very often (twice) and it is hearsay, but where there is smoke, there could be fire.

I have a large brown male BN that was harassing a betta and this is not hearsay, I saw it myself. He chased that betta continually and I had to remove that betta to another tank. This was not a feeding issue, for whatever reason he just did not like that particular fish, he had been fine with other bettas before and is fine with mollys now. To this day I can't figure out what made him behave aggressively in that one case.

I do think BN aggression towards other fish is extremely rare, but I do not doubt that it can happen.

male bristlenose can be agressive, but you need to provoke them a hell of a lot. Normally, they become agressive when food or turf is in short supply. I too have heard stories of bristlenose becomeing agressive but after a little digging you find that the tank was only fed with floating pellets and the bristlenose was starving or they had 8 male bristlenose in a 2ft tank.

Give him a nice bit of wood to call his own and maybe even a nice cave, give him some good algae wafers or better some cucumber and i am sure he wil settle down.

I am sure there are the odd bad egg, but im sure 99% of the time it comes down to an oversight on the owners part, not the fish itself...no offence intended to anyone with an agressive bristlenose. Case in point, Amber is a dedicated bristlenose owner who I'm sure feeds and houses her fish properly, why it would persue one betta in particular is simply one of those unsolved mysteries.

Yes they did say they suspected it was because the goldfish in the tank were probably getting all the food before the Bristlenose got a look in. I have some grown out goldfish fry in a tank with my Bristlenose pair and they are voracious. When feeding I make sure to drop some algae wafers behind the wood and rocks where only the Bristlenoses can get to them.
I plan on moving the goldfish to a pond when the weather gets warmer.

I'll take the rogue BN off their hands and see if I can reform him

Food related... he no's the goldfish will get it first as we all no goldfish are very very greedy....

So I collected him a while ago and he's still in the bag floating in the tank. I have rearranged the tank decor which now inludes a lantern cave his owner gave us and my daughter insisted on taking. He's about three inches bristles to tail and looks like a common Bristlenose to me.





There are two juvenile females in the tank and some goldfish fry but plenty of caves and bogwood. Any advice?

nice looking boy you got there. your tank sounds fine for him. maybe try find an adult female? being stuck in his cave guarding eggs mite settle him down...

kfenk wrote:

nice looking boy you got there. your tank sounds fine for him. maybe try find an adult female? being stuck in his cave guarding eggs mite settle him down...

Might do. I have a female of about his size in another tank but there's a smaller male in there- I'll wait a while and move the female in.

advice...loose the gold fish, bristlenose babies are way cooler!

Doug wrote:

advice...loose the gold fish, bristlenose babies are way cooler!

Good sound advice which I plan on following. As soon as the weather gets a bit warmer here they are going out into the pond.