Somphongs's rasbora
Trigonostigma somphongsi
Also known as Siamese dwarf rasbora, Rasbora somphongsi
Care at a glance
- Temperature
- 73–81°F (23–27°C)
- pH
- 6.0–7.0
- Adult size
- 1 in (2.5 cm)
- Minimum tank
- 12 gal (45 L)
- Temperament
- Peaceful
- Social behavior
- Schooling
- Swim level
- Middle
- Difficulty
- Medium
- Breeding
- Medium
- Rarity
- Very rare
- Origin
- Endemic to the Mae Klong basin in western Thailand.
- Family
- Cyprinidae
Overview
Keep this rasbora in a group of at least eight to ten, more if you can, in a tank of 45 litres or more with soft, slightly acidic water at 23 to 27 C and a pH of 6.0 to 7.0. A dim, planted tank with leaf litter and dark substrate helps them settle and color up. Feed small foods such as micropellets, crushed flake, and frozen or live daphnia and baby brine shrimp. They are shy, peaceful schoolers best kept alone or with other small, gentle species.
In the wild
Somphongs's rasbora comes from shaded, slow, soft-water streams and swamps in the Mae Klong basin of western Thailand. Dense forest canopy keeps the water dim, warm, and slightly acidic. The fish carries a slim dark stripe and a warm orange body, close in shape to the harlequin rasboras. Its native habitat has been badly damaged, so nearly all tank fish are captive bred.
Good to know
Once thought extinct in the wild, Trigonostigma somphongsi is listed as critically endangered and survives mainly through captive breeding. It is the smallest of the Trigonostigma rasboras at about 2.5 cm. It was named after Somphongs Lekaree, a Thai fish exporter active in the mid twentieth century.
Did you know
Buying captive-bred Somphongs's rasbora supports one of the few aquarium species that hobbyist breeders have helped pull back from the edge of extinction.
Where to buy
Some links may not be the exact species or variety.
…or ask your local fish store.
Appears in
Freshwater fish · Barbs, danios & rasboras · Schooling fish · Community fish
Keeping Somphongs's rasbora?
Track water tests, reminders and stocking fit.
Related species

Espei rasbora
Trigonostigma espei1.5 in (3.8 cm)11 gal (40 L)73–82°F (23–28°C)
Glowlight rasbora
Trigonostigma hengeli1.6 in (4 cm)12 gal (45 L)73–82°F (23–28°C)
Harlequin rasbora
Trigonostigma heteromorpha2 in (5 cm)15 gal (55 L)72–82°F (22–28°C)
Dwarf rasbora
Boraras maculatus1 in (2.5 cm)7 gal (25 L)72–82°F (22–28°C)
Gold ring danio
Danio tinwini1.2 in (3 cm)11 gal (40 L)64–79°F (18–26°C)
Orange Hatchet Danio
Laubuka dadiburjori1.2 in (3 cm)13 gal (50 L)68–75°F (20–24°C)
