Sudden aggression in my betta

[Hynsetalia]

I've had my 30 gallon community tank set up for just over a month now. I have 12 White Cloud Minnows, 2 Platys, 1 Plecostomus, 1 male Betta, and 3 Mystery Snails. All was well for the first month, but today my betta has been chasing the platys, trying to bite them, and flaring out his gills and fins. He also will randomly open his mouth really wide, which he's never done before. He completely ignores all the other inhabitants, but won't leave the platys alone. I feed them all flake food, algae tabs, and occasionally blood worms. I don't know why he's doing this. Any suggestions as to the cause or solution?

 

[Andy Sager]

I've had my 30 gallon community tank set up for just over a month now. I have 12 White Cloud Minnows, 2 Platys, 1 Plecostomus, 1 male Betta, and 3 Mystery Snails. All was well for the first month, but today my betta has been chasing the platys, trying to bite them, and flaring out his gills and fins. He also will randomly open his mouth really wide, which he's never done before. He completely ignores all the other inhabitants, but won't leave the platys alone. I feed them all flake food, algae tabs, and occasionally blood worms. I don't know why he's doing this. Any suggestions as to the cause or solution?

There is a reason why Bettas are not usually recommended as community tank fish...they are fighting fish. While many of today's Bettas may not have the need or urge to fight, their whole existence in captivity came from their talents for fighting.
That all being said, there are a couple of possible reasons why he is picking on the Platies and nothing else. 1- they could have attacked him first and this is just his way of getting back at them or 2- he sees them as a competing other "Betta" and so his natural urge to engage the other fish is coming out.
If neither of the fish are being hurt and the Betta is just displaying, there isn't much you can really do. If there is contact and damage, I'm afraid your best choice is to remove the Betta to another tank or container.

Hope this helps.

 

[addisonnolann]

The platys resemble the betta more than any other inhabitant in that tank. He may just be sizing them up to see if they are a threat, or they picked on him first. Try to give it some time. If it keeps going try switching either him or the platys out.


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[addisonnolann]

You could try moving the betta out of the tank for a short time and reintroduce him. He would have to reestablish his territory and shouldn't be as aggressive.


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