Care Guide for Celestial Pearl Danios: Miniature Trout For Planted Tanks

The celestial pearl danio (CPD) is a delightful nano fish often sought by aquascapers because they look like miniature brook trout swimming amid a forest of plants and driftwood. They are a beautiful and elegant addition to any tank in which they live. Sometimes they are shy fish and can become stressful. Find out how to care for these enchanting creatures and make them feel right at home.

What are Celestial Pearl Danios (or Celestial Pearl Danios)?

Danio margaritatus is also known by many other names such as galaxy rasa and celestial pearl daanio. This is due to the striking golden spots that are scattered across their dark bodies. They grow up to 1 inch (2.5 cm) long and feature bright, red-orange fins with black striping. They were discovered in 2006 in Southeast Asia. They live in shallow water with dense vegetation.

How many celestial pearl danios should be kept together? As a schooling fish, they feel most comfortable in large groups so that they can more easily elude predators, find food, and breed. We recommend purchasing 10-15 CPDs for schooling fish. They can be timid so we suggest getting at least six fish from the same species.

When it comes to schooling fish like galaxy rasboras, the more the merrier.

Are celestial pearl danios aggressive? No, CPDs are peaceful nano fish that do well with other community fish. They are still danios and are known to chase each other in an attempt to establish dominance, or show breeding behavior. They are not aggressive towards other species and may occasionally fin nip at their tank mates.

How to Set Up an Aquarium for Galaxy Rasboras

We like keeping CPDs in at least 10 gallons of water, but if you purchase a bigger school of 10-15 fish as recommended, go for a 20-gallon aquarium or larger. They can tolerate a range of pH values from 6.6-8.0 to soft water hardness or GH. Because of their chasing behavior, try adding lots of live aquarium plants for them to dart in between.

Celestial pearl danios are cold-water fish. They can live to 78degF (26degC) but they will thrive at lower temperatures, 72-76degF (20-22 degC). Depending on how warm your home is, you may be able to keep this species in an unheated aquarium without a heater.

Danios and CPDs have lower temperatures than tropical fish.

What type of fish are you able to use with galaxy ratsboras? Try not to put large fish in the aquarium that can eat, bully and outcompete them. In fact, since CPDs sometimes like to hide, consider adding some dither fish that can encourage them to comfortably swim out in the open. We have kept them together with Corydoras Catfish, small Tetras, and Kuhli Loaches. People have had varied results with cherry shrimp as tank mates, so if you try them, make sure to add plenty of hiding spots and expect the CPDs to predate on any baby shrimp they find. Betta fish may or may not work because they tend to prefer warmer waters and can be hostile toward intruders. They may be able to go together if the temperature is kept at 77-78degC (25-26degC), the aquarium is large enough, and the betta isn’t too aggressive.

What does the Celestial Pearl Danios eat?

Because they enjoy swimming in the middle, you might try feeding them tiny, slow sinking foods in the water column. They love baby brine shrimps, frozen cyclops, daphnia, as well as micro worms. As for dry, prepared foods, we like to use crushed flakes and Easy Fry and Small Fish Food. To ensure they have all the nutrients they need to live a healthy and happy life, it is crucial to offer them a variety of foods.

How to Breed Galaxy Rasboras

Celestial pearl danios can be easily bred at home provided that you have at minimum six fish to ensure there is a mix of males as well as females. They prefer media to spawn so give them dense plants like Java moss or a DIY yarn spinning mop. They will spawn almost every day if they are fed well once they have large bellies and a lot of eggs. If you want to stop the adults from eating their eggs themselves, transfer the spawning medium into a separate aquarium. Eggs should hatch in about a week depending upon the water temperature. You can also place the galaxy rosesboras in an outside mini pond that has plenty of aquatic plants during the warmer months and bring them inside at the end to check how many they have multiplied.

Male celestial jewel danios (above), have more vibrantly colored whereas females are rounder.

CPDs that are newborns require fry food smaller than 50 um. This includes infusoria green water and vinegar eels. Live baby brine shrimp is a great choice for fry once they have grown enough to eat. It is packed with healthy fats, proteins and helps them grow quickly.

Because of their beauty, celestial pearl Danios have been a hit with nano tank owners. Our article on the Top 10 Most Amazing Nano Fishes for Your Next Small Fish Tank will give you more ideas.