Madtom belligerance in community tank?

[TownForkCreek]

Two years ago, I netted a Marginated Madtom hatchling which has grown to a healthy 6.6" adult in my community tank, shared with three bronze Corys, a Gold Gourami, and an adult Festivum. (Yeah, I know - unlikely tankmates, but until recently, all was fine.) The Madtom is thriving and has made a den under some larger rocks. He's such a cool little fish. We've really enjoyed him and there's very little info on keeping them.

Lately, my Festivum has begun showing signs of stress (dark color, hiding, clamped fins, etc.) I've been really careful with water quality, pH, temp. etc. The past couple of weeks I've seen some competative behavior between the Festivum and Madtom during feeding, with the Festivum obviously trying to dodge the Madtom. Today I noticed the Festivum had several 'scrapes' on one side. I know Madtoms have venomous fin barbs and wonder whether periodic encounters between the two might be part of what's stressing the Festivium. Unfortunately, I don't have a second tank to shift him to.

Any thoughts/suggestions? I'm treating with Maracin Plus, just in case. Thanks for your help.

[Birger]

I have kept a number of this species together, and they were rather rough with each other, I never kept them with other species though.

You could try adding extra den areas, or break up the substrate a bit by dividing with larger stones. Sometimes I will use slate pieces just to break up the line of sight.

Birger