Celestial Pearl Danios (CPD) is a species of fish that has exploded in popularity in the past few years. It’s not hard to see why, but unfortunately, this resulted in a rapid decline in the quality and health of the current CPDs in the trade. This is due to concerns over the sustainability of catching wild CPDs, resulting in the government of Myanmar, their native country, restricting their export in 2007. Now, it is believed that the concerns were overstated. However, CPDs are now restricted to their current gene pool, and due to the high demand, there is alot of inbreeding, resulting in unhealthy fish. When buying CPDs, it is important to make sure that they are healthy.
Breeding CPDs is relatively easy, they only require being well-fed with foods high in fat. To collect eggs, it is best to use vegetation or something that mimics vegetation, which they will then lay eggs in. The eggs will fall down. It’s best to use a dish or a plastic container to catch the eggs. In a school of 10, you can expect up to 50 eggs in a few days. It is important to collect the eggs often (once every three days) as the infertile or unhealthy fry will mold and kill new eggs. Fry do not eat until they are free swimming, and even then, they are particularly hard to feed. To feed young fry, you need food that is under 50 microns. This can be powered food or paramecium. I recommend “Golden Pearls” as the ideal food for the fry because it floats in the middle of the water column where the fry feed. When feeding powered fry food, either create a suspension of food by mixing it well in water or feed it dry. Make sure to add water to the food to avoid clumping, as then the food becomes too large. Importantly, when raising fry, be sure to avoid selling and or breeding fish that are unhealthy. The most common change in unhealthy CPD is bent spines, from my experience. These fish can still live fine, but it’s not good to introduce them to the already inbred gene pool.
Danio erythromycin and Danio margaritatus were both at one point thought to be part of the genus Rasbora, hence why you see Danio erythromycin being referred to as Dwarf Emerald Rasbora, and Danio margaritatus as Galaxy Rasbora. These common names are rather misleading and are being corrected. Hence, we now refer to Danio Margaritatus as Celestial Pearl Danio instead of Galaxy Rasbora.