Pearl Danio (Brachydanio albolineatus)
Pearl danios (Brachydanio albolineatus) are beautiful iridescent fish that reflect blue or purple in bright light. There is another fish species called celestial pearl danio, but it looks different and is a different species (Celestichthys margaritatus).
Pearl danios are small (about 2.5 inches or 6 cm) freshwater fish from Southeastern Asia. They belong to the family Cyprinidae, which includes goldfish, koi, freshwater sharks, tiger barbs, and many others.
Most sources state that these fish are peaceful community tank fish. However, there are some reports of pearl danios harassing other fish and nipping their fins. While I haven't witnessed this behavior from them personally I thought that it best to at least mention that some people have observed this behavior.
A spacious, heavily planted aquarium will usually help with problem behaviors that may occur. One of the best things you can do for your fish (other than regular partial water changes) is to give them plenty of swimming room and hiding places. Although it may seem counter-intuitive, keeping several fish of the same species in a group seems to cut down on fin nipping and other behavioral problems in fish. This is because the aggression is then spread around and no one fish gets the brunt of it.
Pearl danios are shoaling fish and so you need to keep a group of 6-8 of them in your tank anyway. Their tank should have lots of plants that are located at the back and sides to give them swimming room in the middle.
Pearl Danio Water Parameters and Feeding
They do best at a neutral pH (6.8-7.2), with medium-hard water, and a water temperature around 72-80 °F (22-27°C).
Pearl danios are omnivores (both plant and animal foods) and they will eat just about any of the standard aquarium fare that is offered. A varied diet is best.
Breeding Pearl Danios
Male and female pearl danios look similarly to one another. The biggest difference is that when full of eggs the female will have a more rounded body shape than the male and the male is slightly more colorful.
Breeding pearl danios is similar to breeding any other egg-scattering fish. If you haven't determined the sex of your danios, put a group of them in a breeding tank. The breeding tank should have fine-leaved plants. Put marbles on the bottom of the tank.
The purpose of the marbles on the bottom of the tank is to prevent the adult pearl danios from being able to eat their eggs. The eggs will fall between the marbles where the adults can't get to them.
After spawning is over remove the adult fish and return them to the main tank.
The fry will hatch about 36-40 hours later. When the fry become free-swimming they should be fed infusoria if you have it available. If not, feed them liquid fry food for egglaying fish. The fry will be too tiny to eat larger foods at this point.
About a week later the fry should be large enough to eat newly hatched brine shrimp and powdered dry food for fry.