Max Size: 4cm

Emerald Dwarf Danio (Danio erythromicron)

The Emerald Dwarf Danio are sociable, peaceful little fish appreciating company of its own. Due to the small size, any tank mates would have to be carefully considered as they can be frightened or outcompeted for food by larger or more boisterous tankmates.

However, the presence of similarly-sized, surface-dwelling species as well as plenty of plants to hide in, and an open swimming space seems to help reduce its insecurity.

It's not unusual to see nipped fins within a group though this behaviour does not usually extend to tankmates. Buy as many as you can, ideally ten or more, because when kept in bigger groups, the aggressiveness is spread between individuals plus the fish are more fearless, more often seen, and present better colouration.

The Emerald Dwarf Danio has a pale copper head, a pinkish-orange body with up to 15 iridescent blueish-green bars down the flanks and a single black spot, rimmed in copper, at the base of their caudal fin.

These fish have relatively high bodies giving them a stocky appearance, and their vivid fins set off the emerald green look and provide the fish with a gleaming look in the aquarium.

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℃

Photos of the Emerald Dwarf Danio

Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio
Emerald Dwarf Danio

Natural Habitat

The Emerald Dwarf Danio is indigenous to a mountain lake called Lake Inle and surrounding watersheds located in the western Shan State of Myanmar Burma in Southeast Asia.

Here the inhabit neutral to slightly alkaline water that is clear and shallow with a very rich, loamy substrate. These areas contain dense vegetation and submerged tree roots.

What to feed the Emerald Dwarf Danio

Emerald Dwarf Danios will gratefully accept live, frozen or freeze-dried foods such as brine shrimp, mosquito larvae, daphnia, microworms or bloodworm.

They will also gladly accept micropellets, flake foods and algae wafers providing they can fit into their small mouths.

All of these foods will not only result in the best colouration but encourage the fish to come into spawning.

How to sex the Emerald Dwarf Danio

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.

How to breed the Emerald Dwarf Danio

Emerald Dwarf Danios will breed smoothly and continuously in an aquarium with the correct water parameters.

Females will lay several eggs daily until spawning has completed, but because they seem to enjoy consuming their eggs and fry, it is advisable to have a separate breeding tank. The tank should have several breeding mops or masses of Java Moss so the females can deposit her eggs.

Separate the males from the females and feed them a particular diet of live foods for a week or two before spawning. The fish should be about an inch long and have good colouration when adequately conditioned. When the females have fattened up, add them to the breeding tank and towards evening before the lights turn off, add the males to the tank.

Usually, spawning will begin the following morning and continue for several days. Check the spawning mops or Java Moss daily for eggs and if you notice any take them out and place them into a grow-out tank.

After a week or so, spawning should be completed, and you can relocate your fish back to their original tank.

The grow-out tank should have an adequate air stone in the tank for water oxygenation but no filter for the first couple of weeks. After that, you can use a sponge filter.

The transparent eggs will hatch about 72 hours later if the temperature is quite warm at which time you can see the tiny fry lying on the bottom of the tank.

It would be best if you do not feed the fry until they are free-swimming Which usually takes another a week or so. You can then feed them with infusoria, cyclops, paramecium or liquid fry food daily until they start to develop. After this, you can provide them with commercial flake food, granules or baby brine shrimp.

Small daily water changes with water from the main aquarium should be carried out to maintain good water quality.

After around 6 to 8 weeks, you can slowly add the babies into the main tank. The parents will not be able to eat the fry once they are more significant than their mouths.

Frquently asked questions about the Emerald Dwarf Danio

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: 05/01/2022 16:51:48