Max Size: 2.5cm

Siamese Dwarf Rasbora (Trigonostigma somphongsi)

The rare and stunning Siamese Dwarf Rasbora, Trigonostigma somphongsi, are an extremely rare, beautiful, peaceful little fish that would be a fantastic addition to your aquarium, especially those with planted nano tanks. Unfortunately, these Rasboras are highly endangered due to habitat destruction in the wild, but they are being produced by a few breeders worldwide.

To reduce their shy nature, you should keep Siamese Dwarf Rasboras in schools of at least ten individuals. Furthermore, the aquarium should be large enough to allow sufficient space for the school to swim around.

These fish are safe for keeping with other small, peaceful fish. Despite this, it is easily intimidated, so avoid any aggressive or larger species that may consume or scare it. Because of their small size and peaceful demeanour, these fish would probably do better in an aquarium with only their species or with Dwarf Shrimp.

The aquarium setup isn't critical, but a dark substrate and heavily planted layout will display better colouration. A soft, sandy substrate with driftwood roots or branches set, so there are plenty of caves, and shaded areas will result in a more natural-looking arrangement.

The natural feel can be further enhanced by adding dried leaves such as oak, beech or almond. Decomposition of these leaves will also promote the growth of beneficial microbe colonies. In addition, the decaying leaves will release chemicals and tannins that will simulate blackwater conditions and provide a secondary food source for babies.

As Siamese Dwarf Rasboras do better under reasonably dim lighting, floating vegetation will diffuse the illumination, further benefiting them.

Their elongated transparent bodies in well-conditioned Siamese Dwarf Rasboras display some orange colouration. Additionally, these fish have a thickish black stripe that grows broader towards the anterior, and their fins are transparent except for the caudal fin, which may be orange in colour.

Siamese Dwarf Rasbora (Trigonostigma somphongsi) Video

Siamese Dwarf Rasbora (Trigonostigma somphongsi) Species Profile & Care Guide


Siamese Dwarf Rasbora
Siamese Dwarf Rasbora
Siamese Dwarf Rasbora
Siamese Dwarf Rasbora
Quick Facts
Scientific NameTrigonostigma somphongsi
Other NamesSomphongs's Rasbora
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 10+
Lifespan2 - 4 years
Water Parameters
Water TypeFreshwater
PH5.0 - 7.0
GH2 - 10
TDS18 -143
71 - 79℉
21.7 - 26.1℃


In the home aquarium, the Siamese Dwarf Rasbora 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.

Tank Mates

1 interesting tank mate ideas for the Siamese Dwarf Rasbora could include:

Celestial Pearl Danio(Danio margaritatus)

Sexual Dimorphism

Male and female Siamese Dwarf Rasboras can be distinguished relatively easily. A mature female is usually deeper-bodied, bigger and silvery-yellow in colour. In contrast, males are slimmer and slightly smaller, and once males have settled into an aquarium, they develop a copper-orange colouration.

Other Rasboras of interest

Black Line Rasbora(Rasbora borapetensis)
Blue Line Rasbora(Rasbora sarawakensis)
Chilli Rasbora(Boraras Brigittae)
Clown Rasbora(Rasbora kalochroma)
Dwarf Rasbora(Boraras maculatus)
Emerald Eye Rasbora(Brevibora dorsiocellata)
View all Rasboras
Date Added: 12/07/2021 11:15:36 - Updated: 10/08/2022 18:52:31