Fireline Danio Care Guide (Devario sondhii)

Common Name (s)Fireline Danio
Scientific NameDevario sondhii
OriginSouthern Shan states of Myanmar
Temperature19°C to 25°C
SizeGrow up to 4.5cm
Minimum tank sizeAt least 60 gallons for a school
Food and DietInsects and their larvae
Lifespan5 to 8 years
Water pH6.5 to 7.5 (7.3 ideal)
Tank MatesWith others of the same species, and other small cyprinids that require similar conditions
BreedingEgg spawning species, with breed anyway but a higher rate can be achieved through controlling more factors
Common DiseaseSimilar to other species of Danios

Fireline Danio (Devario sondhii) is a relatively new species of fish to the aquarium hobby. However, they are they are a great addition due to their schooling nature and iconic colouring. Fireline Danios are small and thin, with a reddish orange line on their lower back half and the rest of them being a shimmery silver.

They can be distinguished easily from other species by the dark spot behind their gills. Originating from the Southern Shan States of Myanmar, they are used to waters packed densely with aquatic plants and slow moving water.

Fireline Danio (Devario sondhii)
Fireline Danio (Devario sondhii)

Fireline Danio Care

Fireline Danios are relatively easy to care for. However, as they are fairly new to the aquarium hobby. It is important to ensure that any research done is reliable and that there is less information available about them. Other information, such as that surrounding other similar species of fish may be helpful for their care.

Water temperature

The optimum water temperature in the tank should be kept between 19℃ and 25℃ as they have adapted as a species to subtropical climates. A consistent temperature should be maintained to ensure there are no sudden changes which may impact their immune system, general health or breeding process. Water temperature can easily be controlled and monitored with the right equipment and should be checked regularly.

Water pH

The water pH in the tank should be between 6.5 and 7.5, with 7.3 being the optimum level. The pH should be monitored regularly with testing strips and altered if required. Water changes or movement of fish to another tank can cause a change in pH so these situations are especially important. If the pH is incorrect or changes too suddenly, it can cause difficulty swimming, eating and reproducing and may lead to disease or illness if significant.

Fireline Danio Size

Fireline Danios tend to grow up to around 4.5cm if they are in a healthy controlled environment, however, their growth may be stunted should their needs not be met. Some specimens may grow marginally larger should they be in optimum conditions. Females may be slightly larger than males, though not by a significant amount.

Food and Diet

The diet of a Fireline Danio would likely mainly consist of insects and their larvae, however, due to their schooling nature, they would eat a much more varied diet, depending on which other species are present. They may also eat dried food, which can make up a significant portion of their intake as long as it is of a good quality, which they may occasionally be given frozen options such as Daphnia and bloodworms, as they are known to brighten their colours, though these should be limited as too much may lead to health complications.


Most Fireline Danios will live for between 5 to 8 years as long as factors such as their environment, health and level of care are optimised. Some Fireline Danios may be more prone to disease and will therefore have a shorter lifespan, while some may outlive their expectation.

Tank Setup

Due to the fact they originated from rivers and flooded grasslands, they thrive in environments with dense vegetation, possibly some floating plants and a slow-moving current. A fast moving or strong current should be avoided as Fireline Danios have not adapted sufficiently to suit this type of swimming meaning they may be outcompeted for food. Around half of the water should be replaced each week, however, they are known as a species to unpredictable and possibly jump out of the water so care should be taken when removing the top of the aquarium, even just for short times.

They are a schooling species and therefore thrive better in a social environment with at least 5 Fireline Danios, though more, upwards of 10, are suggested. More specimens will make the school more comfortable, the display more stunning and will encourage healthy competition for mates. This means that the tank should hold at least 60 gallons to ensure sufficient space, however, larger may be required if you have more fish, especially if they are being housed with other species as well.

Breeding Fireline Danio

Fireline Danios are a species that spawn eggs and lack any parental care, meaning they will reproduce naturally in a tank with all their conditions met. However, to increase the rate of reproduction, a more controlled approach can be optimised. The group of adult fish to reproduce should be separated into a dimly lit, smaller tank, though ensure doing this is not detrimental to any fish left over in the original tank. A mesh should be set up to allow the eggs to fall through but not large enough for a fish to fit, so that the eggs are not eaten. Factors such as oxygenation, pH and filtration should be monitored but there should be offspring swimming around within days. Females can be identified by their slightly rounder bodies as well as being generally duller in colour compared to males.

Common diseases

As mentioned before, Fireline Danios are newer to the aquarium hobby and therefore there is a lack of information surrounding illnesses they commonly suffer from. However, Danios in general tend to be affected similarly from diseases and so it is safe to assume that Fireline Danios are vulnerable to the more common ones as well. They are unsuited to unclean water, and this can therefore lead to complications quickly, so cleanliness is important to be sustained. Mycobacteriosis causes inflammation of the internal organs and can therefore be fatal. Antibiotics can be used to treat it, but it can come back after the course is finished meaning there may not be much to do to keep them healthy. Prevention is much more important than treatment to ensure they are healthy.

Tank Mates for Fireline Danio

Fireline Danios are a social species and are kept well with other Danios and any other peaceful fish with similar environmental conditions. Other small Cyprinids and some species of shrimp are usually compatible.

Where to find Fireline Danios for Sale

Fireline Danios are available for purchase for around $6 per fish however, some can only be purchased in numbers higher 2 to ensure they have a social environment. They can be bought in store or online, however, try to only buy from legitimate sites that take care of the specimens and ensure they are in good health and have suitable conditions. Not all general pet stores may stock Fireline Danios specifically, though they will likely have at least one species of Danio.

Fireline Danio vs Zebra Danio

Zebra Danios requires similar conditions to Fireline Danios, although not quite the same. They tend to live closer to 5 years, have a pH of around 6.5 to 7, and tend to be a cm or two larger as a species. However, the water temperature is very similar as well as their tank mates and are also a schooling species. Both Danios are an excellent fish for beginners and get on well should they be housed together.