Tomini aggressive towards marine betta?

[i_declare_bankruptcy]

I finally found a marine betta (been waiting for a while) and added him to my tank. He's about 3.5-4". He is very healthy and eating just fine. Today I noticed a few chunks missing from his tailfin and, while examining, watched my tomini tang chomp at him. I find this odd since my tomini tang is a complete wuss and hides from most fish (but gets along with my foxface). The tomini tang is an adult, about 5-6". Again, both fish eating no problem, and the tomini tang is quite fat and happy.

I'm willing to take either back to solve the problem, but is there anything else I can do? Both those fish are awesome and it'd be a bummer to have to sell one. I didn't think there was going to be an issue as I've read marine bettas and tangs typically coexist peacefully. There is a lot of live rock to hide in in my 525XL and the betta typically sticks to a corner where the tang doesn't go but if he ventures, the tang will occasionally make an aggressive pass at him. I have had the betta for about a week and the tang for months (but did rescape about 1.5 months ago).

The betta, foxface, and tang are the only "larger" fish in my tank.

 

[Flippers4pups]

How long have you had the Tomini?

 

[Alexreefer]

Marine bettas are really hardy fish mine went through everything possible and still survived. keep and eye out and im sure flippers will help you

 

[i_declare_bankruptcy]

How long have you had the Tomini?

About 3 months, rescaped the tank about 1-1.5 months ago.

 

[Gregg @ ADP]

Probably a little ‘getting to know each other’ stuff. Keep an eye on the fins. If you see more damage, somebody might have to go. A lot of this stuff phases out after a week or so.

 

[Flippers4pups]

About 3 months, rescaped the tank about 1-1.5 months ago.

Aggression from established tangs is very well known, even small bristle tooth ones. The only way of rearranging the rock trick would be effective, would be to remove the tang for a short period and once the rock is rearranged, reintroduce the tang.

 

[i_declare_bankruptcy]

Probably a little ‘getting to know each other’ stuff. Keep an eye on the fins. If you see more damage, somebody might have to go. A lot of this stuff phases out after a week or so.

Aggression from established tangs is very well known, even small bristle tooth ones. The only way of rearranging the rock trick would be effective, would be to remove the tang for a short period and once the rock is rearranged, reintroduce the tang.

Thanks. I'll keep an eye on him. It's not constant/consistent aggression; I think maybe the betta needs to learn about what areas of the cave are the tang's. It seems to be localized to a specific spot and when the betta is out of the area the tang ignores him. The tang and fox face are like best buddies; they always graze on the same patches together it's funny to watch. Foxfaces are some seriously clumsy/awkward fish lol.

I know they're tough fish but I don't want him to have a miserable existence so I'll keep a close eye and if it doesn't stop I'll banish the tang to the sump and redo the rocks and reintroduce.

 

[Flippers4pups]

Thanks. I'll keep an eye on him. It's not constant/consistent aggression; I think maybe the betta needs to learn about what areas of the cave are the tang's. It seems to be localized to a specific spot and when the betta is out of the area the tang ignores him. The tang and fox face are like best buddies; they always graze on the same patches together it's funny to watch. Foxfaces are some seriously clumsy/awkward fish lol.

I know they're tough fish but I don't want him to have a miserable existence so I'll keep a close eye and if it doesn't stop I'll banish the tang to the sump and redo the rocks and reintroduce.