One of the classic fishes of the aquarium hobby, pearl danios are often neglected by aquarists, despite their truly beautiful patterns. While they don't show the best colouration in photographs (especially mine), the fluorescent blue of the body, set off by the red in the fins, is truly stunning. Further, pearl danios -- like many of the classic danios -- are all but indestructible. These are among the hardiest of fish.
Like most cyprinids, pearl danios will do best in large groups, though they may shoal with similar shaped and patterned fishes (e.g., other danios). Care should be taken to keep the aquarium covered, especially for new fish, as they can be quite jumpy (in fact, having one jump out of the tank is probably the only way they'll die).
Pearl danios may be maintained outdoors in the warmer months, and make great mosquito controllers in a small pond or tub. They are incredibly easy to breed, and in a tank with sufficient cover, fry will often be found without interference from the aquarist.