Max Size: 4cm

Emerald Dwarf Danio (Danio erythromicron)

Emerald Eye Rasboras are a peaceful and very hardy species of Rasbora, making them an ideal resident of the community aquarium.

These Rasboras have no particular demands regarding water chemistry; therefore, you can house them with the most popular species in the hobby. These include other small Cyprinids, Tetras, Livebearers and Dwarf Cichlids, and Catfish and Loaches.

Emerald Eye Rasboras are a tight shoaling fish that can be rather timid; therefore, it would be better if you kept them in groups of 10 or more individuals. Larger groups will help your fish feel more secure and result in a more effective, natural behaviour. In addition, males will display their best colours as they compete for female attention.

In the aquarium, the decor choice is not as important as the water quality. However, these fish look especially effective in a well-planted aquarium with a dark substrate.

Emerald Eye Rasboras thrive in a natural-style set-up with a soft, sandy substrate and a few driftwood roots and branches to form plenty of shady areas. The addition of dried leaf litter further accentuates the natural feel. The leaves also offer even more cover for the fish and bring on the growth of microbe colonies as decomposition occurs.

Emerald Eye Rasboras prefer reasonably dim lighting, although this does hinder the use of some aquatic plants.

The Emerald Eye Rasbora is an elongated fish with a pointed nose. Their base colour is a reflective, metallic silver; however, the fish can take on a yellowish hue under some lighting conditions, with a slight pink blush in the central area of the body between the pelvic fins and the operculum. In addition, these fish sometimes display a thin olive gold-tinted parallel line from the operculum to the caudal peduncle under reflected light conditions. All their fins, except for the dorsal fin, are hyaline.


Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio
Quick Facts
Scientific NameDanio erythromicron
Other NamesEmerald Dwarf Rasbora, Thick Band Purple Zebra Danio, Cross-banded Dwarf Rasbora
Aquarium LevelBottom - Middle
DifficultyBeginner - Intermediate
Best kept asGroups 10+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH7.2 - 8.2
KH2 - 10
TDS150 - 300
69 - 77℉
20.6 - 25℃


In the home aquarium, the Emerald Dwarf Danio will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Sexual Dimorphism

It is relatively straightforward to determine the difference in sexes. The males are more intensely coloured and are slightly smaller than females, and they also have a reddish-orange hint on their fins whereas the female's fins are transparent and colourless and their abdomens are more rounded than that of the males.

Frequently asked questions

Are Emerald Dwarf Danios a shoaling fish?

Yes, in nature, Emerald Dwarf Danios are shoaling fish that swim together. It would be beneficial to your fish if you purchased at least 6, preferably more. You will find that your fish will fare much better and live longer in groups of their own kind.

Are Emerald Dwarf Danios suitable for community aquariums?

The Emerald Dwarf Danio makes an excellent member of the community aquarium, providing you house them with smaller species of fish. These fish get on fine with similarly sized or smaller species and are ideal for the beginner aquarist. It would be best if you did not house Emerald Dwarf Danios with larger, very active or aggressive species.

How big do Emerald Dwarf Danios get?

Emerald Dwarf Danios, when fully developed, can reach somewhere between 2.5 cm and 4 cm in length. So these fish are not very big, making them excellent fish for the nano aquarium.

What does Emerald Dwarf Danios look like?

Emerald Dwarf Danios have blueish green bodies displaying iridescent turquoise stripes down their flanks. The anal and pelvic fins have a reddish-orange hue, and they usually have a black spot to the rear of the caudal peduncle. These fish also have pinkish gold colouring on their head through to the dorsal area.

What should you feed your Emerald Dwarf Danios?

Emerald Dwarf Danios will accept most foods in captivity. However, it would be better to provide your fish with good quality dried food such as pellets, flakes and granules as the staple and then give them live, frozen or freeze-dried foods once or twice a week. Also, it would help if you remember these fish are tiny; therefore, make sure the size of food is small enough for them to consume.

Where do Emerald Dwarf Danios originate?

Emerald Dwarf Danios originate from an isolated mountain lake of Inle and the surrounding waters in Shan State east of Myanmar. You can also find these fish near Loi Kaw in the neighbouring State of Kayah in Southeast Asia.

Other Danios of interest

Assam Danio(Devario assamensis)
Barred Danio(Devario pathirana)
Bengal Danio(Devario devario)
Black Barred Danio(Danio absconditus)
Blood Tailed Danio(Devario annandalei)
Blue Danio(Danio kerri)
View all Danios
Date Added: 30/09/2020 - Updated: 11/08/2022 15:24:33