I've had my lovely black-lace butterfly betta, Atlas, for a few months now. My other two fish, Galileo and Aristotle, have been in my possession just a few months longer.
But Atlas is the only one that ever acts this way.
Every time we go for a water change, his behavior changes as if he's going to die and he acts like a total drama queen.
When I cup him he sinks like a rock to the bottom, spreads out his fins (but not a flare) and starts breathing in a way that I can only describe as spastic hiccuping. He rarely ever goes to the surface during this time, but when he does, he takes several breaths at once, swimming quickly and keeping his mouth above the water.
When he doesn't go to the surface and stays at the bottom the whole time, he starts to lean to the side as if he's dead.
When it's time to go back home, his initial cupping behavior repeats, except sometimes he'll regurgitate. When he gets back into his home, he sinks to the bottom the same way he did when he was cupped, but he recovers after some time.
What's happening to him? I've currently got him in a quarantine tank with some salt and bettafix in the water, because his recent behavior has been the worse case so far. This is the second time he's been quarantined within 6 months. He's the only one of my fish that does this. I'm worried that one day he'll get traumatized to death.