I agree- unless you know exactly what they are, stay away from those fish. Don't ever plan on keeping "mystery" fish with others until you've got a good idea what they are.
Unfortunately, even if you have a basement filled with 125-gallon tanks, there's no way you can save all the fish that show up at a bad store. The more you buy, the more they'll get.
Unfortunately, even if you have a basement filled with 125-gallon tanks, there's no way you can save all the fish that show up at a bad store. The more you buy, the more they'll get.