Have you ever wondered why some colors are more difficult to find in nature? If you have, then you’ve probably come to the realization that blue is one of those colors, and is also one of the rarest colors for most types of aquarium fish.
This makes these blue-colored fish a well-sought commodity in the fishkeeping world. Such coloring is due to a black pigment combined with what’s known as “iridocytes” in the skin that makes the fish appear blue as a result of the incoming light.