Agressive miniatus grouper

[MarcusRogers23]

I have a miniatus grouper in my 150 and he has caused no trouble whatsoever. I have recently added an australian harlequin tusk and he seems to only occasionally pick at him, no one else. The harlequin is still eating but his tail is damaged from the nipping. I put a mirror on one side of the tank and it does keep the grouper distracted and has decreased the nipping a lot but he still does it occasionally. Any ideas of what i should do?

 

[eastlake]

How long has it been? Since the tusk is a new addition it's not at all odd for an established fish to let the new guy know who rules the roost. If it continues, even after say a couple of weeks, then you could re-arrange the rocks in the tank so the grouper has to stake out a new territory and lose focus on the tusk. It's also possible that the grouper feels that it owns the whole 150, how large is the grouper?

 

[Uncle99]

How long has it been? Since the tusk is a new addition it's not at all odd for an established fish to let the new guy know who rules the roost. If it continues, even after say a couple of weeks, then you could re-arrange the rocks in the tank so the grouper has to stake out a new territory and lose focus on the tusk. It's also possible that the grouper feels that it owns the whole 150, how large is the grouper?

Yup, the mirror, a change in scape, time, maybe...the tank is a bit small for this fish, I'm thinking 200g. With the groupers, I'm not sure if he's chasing or trying to eat and won't fit.

 

[MarcusRogers23]

How long has it been? Since the tusk is a new addition it's not at all odd for an established fish to let the new guy know who rules the roost. If it continues, even after say a couple of weeks, then you could re-arrange the rocks in the tank so the grouper has to stake out a new territory and lose focus on the tusk. It's also possible that the grouper feels that it owns the whole 150, how large is the grouper?

It has been about a week. I changed the landscape of the rock and the grouper is about 5 inches and so is the harlequin tusk. The aggression has died down a lot since when I first introduced the harlequin but his tail is damaged. He is still eating, so I am hoping his tail will heal.

 

[eastlake]

Fins heal quickly, if the aggression has stopped then the tusks tail should look as good as new in no time.

 

[Cliving1]

Just be careful, groupers have big mouths. I had a friend who used to have that exact kind, he could not get his hand in without it biting. I would choose the tusk over the grouper...hopefully you can have both. Good luck!

 

[zachfishman]

Sorry, but that Miniatus will only get more aggressive with time. I had one in a 700 gallon FO that slowly started working its way through fish. It'd target and bully one fish to death, then select another victim. Finally got rid of it before it killed fish #3.