Roseline sharks bullying

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.


Aquarium Advice Newbie
May 8, 2022
Hello! I’ve had 3 roseline sharks for a few months now in my 29 gallon tank. Out of no where, one of them started bullying the other. His fin is being nipped and this morning he wouldn’t eat. I have him in a 3-way isolation tank for short term recovery but I’m worried if I put him back he’ll just get bullied again. I posted on a Facebook group about this and was verbally attacked for having roselines in such a small tank (29 gallon). The local fish shop owner did not see this being an issue when he sold them to me (he’s an honest guy and has stopped me from buying unsuitable fish before) so I’m confused why some people said I should rid them. Is this why one is bullying the other?
While being verbally attacked isnt acceptable, a 29g tank isnt big enough for these fish.

Rosaline sharks/denison barbs are social fish, and keeping social fish in small numbers is stressful for them. This stress can manifest in different ways in different individual fish and aggession is one of those ways it can manifest.

29g simply isnt a big enough tank to support a large enough group of these fish for them to be comfortable. Keeping a few more in a larger tank may solve your aggression issue. Having said that, some fish are just jerks.
Last edited:
Top Bottom