I'm not so sure that was Cthulu's fault. You see, plastic bags are actually toxic to marine life.And even if you don't take that into account, they're still not good for long-term storage. Without a filter to remove soluble waste and introduce more dissolved oxygen, the water will quickly become uninhabitable, especially given how little air these particular bags seem to contain relative to the water. Not to mention how difficult it would be to feed them without causing the bag to spill. You should only ever keep a fish in a non-aquarium container as a temporary arrangement, like if you need to clean their tank, or when you're taking them home from the pet store.