It's certainly possible. What I'm trying to figure out is how do they successfully sell *ANY* fish like that? If I go and buy a fish, and it promptly dies, then go back to get a new one and it dies, repeat X times, how high does X have to be before you never go back and tell all your firends to stay away? Conversely, how many returns of dead fish does a store have to get before a manager asks the question: "maybe the problem really isn't our customers, I wonder what we're doing wrong?"
Even so, there is something wrong with the fish. And, it seems to be a consistant something, particular to the larger swordtails I get from stores. I've goten some small black swordtails and they're doing great.
As the LFS, I watch the tank for a bit and make sure I don't see any signs of disease. If I do - dead fish, columnaris, fungis, ich, etc, etc, I pass. If I don't, I watch them and look for some of the active ones. Those are the ones I take home. But, when I get them home, they hover around and hide, don't eat and eventually die. I suspect that the problem is not with something I'm doing during the acclimation process, as I've brought home other fish with batches of swordtails that have died, and the other fish do well.
I know that I should probably not care too much, because it could be a lot of different things, but the facts are that the fish made it to adulthood in conditions that are probably much worse than my tanks, they live in overcrowded, too small tanks until someone buys them, I tank them home put them in my tank with good water, space, places to hide and then they die. I was starting to suspect that the LFS' were including some form of medication that suppressed symptoms (either intentionally or unintentionally) that doesn't exist in my tank, but I've been assured that isn't the case. So anyway, the fish are sick when I get them home or the stress of bringing them home makes them catch something. What I want to find out is - what is it? It's not fungal, and I don't think it's bacterial - I've tried treating them with maracyn or tetracycline (different times, different batches) and neither has helped. So, that probably means its either viral or parasitic.
I realize I'm way overthinking this, but that's how I am. Any insight would be appreciated. I can't just let them have died without understanding why.
