Most fighting occurs when there is breeding competition, but I have seen my four female auratus meet up and do a bit of slapping on rare occasions, and the all female glactonotus will very rarely do a little wrestling that doesn't last long. I don't have any tincs yet, but am getting a group of unsexed azureus soon, so should get some experience with these, which are closely related to tincs.
The most vicious fights I've witnessed have been among a 2.2 group of imitators. Both females went for the same male. The other male just stayed the heck out of the way. They chased, head-butted, wrestled, bull-dogged and threw each other around. They never seemed to injure each other, so I just left them and they raised up a couple of tads that morphed out, even fighting over which female was going to feed them. It was fun to watch the first time. Now I have them separated into a 1.1 and another group situation. Oddly, the group is still having fights, but laying more eggs and raising tads, while the 1.1 have laid a few eggs, but don't seem to be taking care of them as well, and haven't packed any tads off to a bromeliad yet. One can't conclude anything from this.
I'm hoping Homer will come on with his tinc experiences. I think he keeps them in groups and not sexed pairs.
The photo is of the slapping contest, a fourth frog is out of range of the camera and about to leap in the middle of them. It was about the most interesting thing these shy blue auratus have ever done. I scared them off with the flash, which went off when they had their hands to themselves for a brief moment.

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Patty
Pahsimeroi, Idaho
4 D. auratus blue
5 D. galactonotus pumpkin orange splash back
5 D. imitator
6 D. leucomelas
4 D. pumilio Bastimentos
4 D. fantasticus
4 P. terribilis
4 D. reticulatus
4 D. castaneoticus