They're probably Pacus. I don't give any of those fish long. It's a bit hard to tell, but I don't see any surface agitation either. It looks like there's an intake tube on the left, but the filter doesn't seem to be running.
Also, I never liked the tank on a towel idea. In the long run, it's not truly going to keep moisture off the stand...plus, in time I am sure it will be a moldy mess underneath.
Not that it matters, but it looks more like a 20g than a 10.