The Blue Diamond discus is a man-made, cultivated strain of discus. Dating back to 1990, Malaysian breeders began to notice a shift in their Blue Turquoise discus. Starting transparent in color, the Blue Turquoise discus fry would grow out into a solid blue color, losing the patterns on the gill and fins, as well as stress bars that are typical to the Blue Turquoise discus. A genuine Blue Diamond discus fish will have this solid blue body, as well as red eye color. Occasionally, one may see some slight yellowing on the tail fin, in addition to but not always including smaller sized scales. Unlike the Cobalt discus, the Blue Diamond was selectively bred to remove vertical striping.