Yeah glass fish are see through. Very Cool, had them before. You may see the colored glass fish, DO NOT BUY THEM. They inject the fish with a harmfull chemical to make them a flouresent color. The ones you see in stores are ones of the rare surviors ( about 1 out of 1000 live, after being injected) but still are probably going to die shortly or are very weak. I think it is a real shame that they do such a cruel thing