Somphong's Rasbora
Somphong's Rasbora
Somphong's Rasbora (Trigonostigma somphongsi) is one of the rarest and most conservation-significant rasboras in the hobby — listed as Critically Endangered by the IUCN, with a highly restricted wild range in the lower Mae Klong basin near Ratchaburi Province, Thailand. Named for Somphong Lek-aree, a Thai fish explorer and aquarium trader who first discovered the species. The black marking is the most reduced of the Trigonostigma group — a thin line rather than a triangle — on a pale body with warm iridescent tones.
Feeding & Care Tip: Sera Vipan Tropical Flakes and Hikari Micro Pellets make excellent daily staples. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Baby Brine Shrimp, Hikari Frozen or Freeze-Dried Tubifex Worms, or Hikari Vibra Bites. Feed small amounts 2–3 times daily.
Native to the lower Mae Klong basin near Ratchaburi Province, Thailand — a region that has already lost the Bala Shark (Balantiocheilos melanopterus) and the Dwarf Chain Loach (Ambastaia sidthimunki) to habitat destruction. Wild collection locations for T. somphongsi are not publicly disclosed by conservationists to protect what remains of the population. Breeding in captivity is a genuine conservation act for this species.
Keep in groups of at least 8. Soft, slightly acidic water with dense vegetation and tannin additions produces the best coloration and most natural behavior. Peaceful and somewhat shy — avoid boisterous or larger tankmates.
The spawning behavior of Trigonostigma rasboras is unique and fascinating — the female inverts completely to place eggs on the underside of a broad leaf, then the pair separate and the eggs develop without parental care. Cryptocoryne leaves are the traditional natural spawning site. Given its Critically Endangered status, Somphong's Rasbora is best suited to dedicated breeding projects or biotope setups that support population maintenance in captivity. Every captive breeding success is a meaningful contribution to this species' survival.
Care & Ideal Parameters
| Difficulty | Easy — Moderate |
| Temperament | Peaceful — conservation priority species |
| Typical Adult Size | 1.25 inches (3.2 cm) |
| Min. Group Size | 8 minimum — breeding recommended |
| Ideal Temp | 72–79°F (22–26°C) |
| Ideal pH | 6.0–7.0 |
| Ideal GH | 1–8 dGH |
| Ideal KH | 0–4 dKH |
| Staple Food | Sera Vipan Tropical Flakes; Hikari Micro Pellets |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Baby Brine Shrimp; Hikari Frozen or Freeze-Dried Tubifex Worms; Hikari Vibra Bites |
| Origin | Lower Mae Klong basin, Ratchaburi Province, Thailand (IUCN Critically Endangered) |
| Notes | IUCN Critically Endangered. Named for Somphong Lek-aree, Thai fish explorer. Wild locations not publicly disclosed for conservation. Same area lost Bala Shark and Dwarf Chain Loach to habitat destruction. Breeding in captivity = conservation contribution. Thin black line vs triangle. |
