Somphongs’s rasbora (Trigonostigma somphongsi) is a small, tropical, minnow-like cyprinid fish native to the Mae Khlong basin of Thailand. It is one of four species in genus Trigonostigma. It is considered critically endangered by the IUCN Red List of Threatened Species, as well as placed on the world’s 100 most endangered species list, due mainly to habitat degradation and development for farmland in addition to pressure from fishing. Somphong’s rasbora is highly sensitive to vegetation loss; it lays its eggs at the base of aquatic plants in a spawning behavior unique to, and characteristic of members of this genus. This species experienced a >90% population decline and in fact was considered extirpated as it was not been seen in the wild for more than twenty years. More recently individuals occasionally show up among catches of other small fish shipped from Thailand to Europe for the aquarium trade indicating there are existing populations. The localities and size of these populations are unknown but considered to be declining and presumably very local. Breeding captive populations do exist, and if wild populations can be identified and their habitat restored and protected, it may be possible to support existing wild populations by reseeding them with captive stock.
- Kottelat, M. and K.E. Witte. 1999. Two new species of Microrasbora from Thailand and Myanmar, with two new generic names for small Southeast Asian cyprinid fishes (Teleostei: Cyprinidae). J. South Asian Nat. Hist. 4(1):49-56.
- IUCN Media Statement Sept 11, 2012. The 100 most threatened species. Are they priceless or worthless? http://www.iucn.org/media/media_statements/?11007/The-100-most-threatened-species--Are-they-priceless-or-worthless
- Malein, F. 11 Sept., 2012. The 100 most endangered species on the planet – the list in full: The full list of fauna and flora listed as the most endangered by the IUCN and Zoological Society of London. The Guardian. Environment section. The sixth extinction. http://www.guardian.co.uk/environment/2012/sep/11/100-most-endangered-species-planet
Vidthayanon, C. 2011. Trigonostigma somphongsi. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.
. Downloaded on 13 February 2013.
- Doi, A. 1997 A review of taxonomic studies of cypriniform fishes in Southeast Asia. Jap. J. Ichthyol. 44(1):1-33. (Ref. 26580) http://www.fishbase.org/references/FBRefSummary.php?id=26580&speccode=56155
- Baensch, H.A. and R. Riehl 1991 Aquarien atlas. Bd. 3. Melle: Mergus, Verlag für Natur-und Heimtierkunde, Germany. 1104 p. (Ref. 2059) http://www.fishbase.org/references/FBRefSummary.php?id=2059&speccode=275
Habitat and Ecology
IUCN Red List Assessment
Red List Category
Red List Criteria
It appears that the species is still present in the wild within its previous range, but the location of the specimens found in the aquarium trade is not currently known. The species is assessed as Critically Endangered based on its previous population decline of more than 90%.
Further research is needed to confirm the source of remaining specimens from the wild and should benefit from conservation effort to protect habitat and prevent further exploitation.
Although considered possibly extirpated, it is apparently still present in the wild, but probably in localised populations.
- IUCN 2006 2006 IUCN red list of threatened species. www.iucnredlist.org. Downloaded July 2006. http://www.fishbase.org/references/FBRefSummary.php?id=57073
The species is listed in the Thai Red Data book as threatened.