One of the most exciting new fishes in the past few years, the Celestial Pearl Danio, or Galaxy Rasbora, has been bounced around between fish groups rather a lot since its discovery. For those that care, the fish was originally believed to be a form of Microrasbora, but recent work has found it is more closely related to the danios, and deserving of its own genus, of which the similar previous Microrasbora, Celestichthys erythromycin, has been placed. Care should be taken when maintaining these two small, similar looking fishes, as they may produce hybrids in the aquarium, and it is suspected that some of our hobby strain may already have been contaminated.
These beautiful, small fish will do quite well in a heavily planted tank. Males may spar with each other, and any tank containing multiple males should have plenty of cover to prevent damage. Despite their small size, they really do better in larger tanks. They should only be maintained with other small fish that will not prey upon the tiny danios. Any of the smaller types of Apistogramma would be ideal, as would mixing with other small cyprinids, tetras, and catfishes.