They are really peaceful fish that take in algae and greens, with shades that blow other fish out in the drinking water. Graphic Editorial Credit: Wikimedia Commons The Satan’s Gap Pupfish is probably the rarest fish on the earth, found only in one, remote site. This very small, vivid fish https://www.slideserve.com/aquariumshops/how-to-enhance-your-fish-pond-pearl-aquatics