Yesterday I had purchased a dwarf gourami? It looked healthy at the store. I did notice when they were bagging that they placed no meds in the bag. I also realized that the employee had placed my other purchase of an African dwarf frog in the same bag. Every one was acclimated into my 10 gallon and the gourami did seemed stressed out this morning was giving no signs of stress. I then came home today to find that the gourami was breathing heavily and lethargic. I kept an eye on the tank for a good hour and within that time the gourami began thrashing almost, and swimming very fast.... within 3 minutes later it had passed. What could have caused this issue? The store I buy them from is usually very good at handiling fish and I have had no issues in the past. My Levels are all correct and my 4 neon tetras and corydora catfish are fine as well and have showed no signs of stress either or failing health.