Danio margaritatus – Rasbora Galaxy
Danio margaritatus was officially described by Roberts in 2007. He described the species as Celestichthys margatitatus. However, more recent research showed that this species actually belongs to the genus Danio. Therefore, the official scientific name is: Danio margaritatus.
In Latin, margaritatus means: decorated with pearls. This refers to the white spots that can be found on the body of these fish. This reference can also be found in the common name, which is: Celestial Pearl Danio or simply Pearl Danio.
The body of the Pearl Danio has a greenish bleu to dark blue coloration, with white spots. These white spots are the “pearls” which were mentioned above. The pectoral side of the body is bright red just like most of the fins. Beside this red coloration, the fins also show black stripes. The caudal fin, however, is only red on the outer sides of the fins.
Distinguishing the differences between both sexes is rather hard to do. The difference can be seen on the hand of the coloration of the fish. Males are brighter coloured while the colours on the females are a bit dull.
Distribution and Habitat
Danio margaritatus can be found on small ponds in Myanmar. These ponds have very clear and clean water. The temperature measured in these ponds in January 2007 ranged between 22 to 24 °C. The ponds are also rather shallow, with an average depth of only 30 cm.
These ponds are found in open grasslands where they are formed by springs or water that flows out of small streams. These sites are filled with lots of aquatic plants. Most of these plants belong to the genus Hydrocharitaceae.
In their natural habitat these fish do most likely feed on small insects and their larvae. Furthermore, will they, probably, also eat plankton.
Pearl Danio’s that are bred in the aquarium will accept all types of food as long as it is carnivorous. However, they will prefer live prey such as daphnia to granulate or flakes. Feeding daphnia or brine shrimp is not only preferred by these fish, they will also enhance the colours on them.
Specimens that are wild caught, tend to accept only live foods. Therefore, in order to get them used to factory foods, you should get them used to it slowly.
These Danios are rather shy. This might cause starvation of these animals as larger or more dominant species will eat all the food before the Pearl Danio get a chance to eat. In order to prevent this, this specie should only be kept with smaller inhabitants.
Danio margaritatus is rather aggressive towards specimens of its own species. Males will try to impress or hunt down each other. Torn fins are, therefore, not an uncommon sight. Real damage to the fish can be prevented by keeping a large shoal. This will spread the aggression more equal between the fish.
Breeding the Pearl Danio is best done in a separate fish tank. This tank should be decorated with a lot of small leaved plants. Java moss is preferred for this purpose. The fish will spawn their eggs between these plants. Instead of live plants, artificial decorations such as spawning mops could also be used. If the tank is fully decorated than the fish could be introduced. Do not put too many fish in this tank. The more fish that are present, the higher the risk of egg predation. For the same reason is it necessary to catch the fish as soon as the eggs are spawned.
The females will lay up to 30 eggs for each period of spawning. These eggs will be about 1 millimetre wide. This is just a bit smaller than the dots on the adult fish. After 3 to 4 days, the eggs will hatch. Four days later the fry will start to swim freely throughout the tank. At this point in time, one could start feeding them. The food for the fry should be very small. Paramecium or very fine dry food is the best pick. Once the fish become larger, you could also start feeding them with artemia naupliën or microworms. When the young fish have become twelve weeks old, they will start to develop the pattern that is present on adult fish.
Rick – LauMooij – John de Lange
Roberts, T. R. (2007). The “celestial pearl danio”, a new genus and species of colourful minute cyprinid fish from Myanmar (Pisces: Cypriniformes). The raffles bulletin of Zoology, 55(1), 131-140.