Aggressive Male Molly

[xc10446]

I have 7 mollies in a 10 gallon tank. I'm looking to move these fish to a larger tank soon, but that's a separate topic.

Today's question is regarding my one black male Molly. He's singled out just one female and chases her constantly, slaps her with his tail, and shows generally poor manners. He's 100% okay with the other 5 female fish, and the other tank-mates. The picked-on Molly has been hiding for the past couple weeks, but she still looks healthy. Any tips for dealing with the trouble maker, or should I just get rid of him?

 

Images:

1. black male Molly, isolated

2. black and gold Molly, out of hiding and healthy

[Phantom240]

I had a really aggressive female molly, we jokingly called her "tank boss", who would constantly pester every other fish in the tank at feeding time, aside from my male betta who she knew not to mess with. It got to the point where some of the other mollies, even the couple of males, would hide from her as best they could. I put her in another tank for a while, a time-out tank, and did some mild rearranging of the tank. A couple of months later, I reintroduced her. She was still mildly aggressive at times, but not nearly as bad. Perhaps a breeder net box would have the same effect. I think breaking line of sight and preventing setting up of territory for a sufficient amount of time helps with aggression. 

 

Mollies are little buttholes. 

Edited July 8, 2021 by Phantom240