I think I might have something of a problem. I am housesitting for my sister, and one of her tropical fish (I'm not sure of the type, but it's about 5cm long) seems to have a peice of gravel caught in it's mouth. I'd post a picture but my camera is at home. There are a few unnatural (they weren't there before) red specs visible around where the stone is, and the fish doesn't look too comfortable.
What should I do?
What should I do?