Thank you Juris for this Cambodian cover! Four stamps from a complete set of six (date of issue 1999) depicting tropical fish are shown on this letter.
The 200 riels stamp (the riel is the currency of Cambodia) depicts two tiger barbs or Sumatra barbs (Puntius tetrazona) a very popular fish in the aquarium trade.
The rainbow shark (Epalzeorhynchos frenatus) with its black and greenish body and its red fins is also a popular freshwater community-tank aquarium fish of the Cyprinidae family.
The Orange chromide (Eutroplus maculatus) is a species of fish to freshwater and brackish streams depicts on the 1,000 riels stamp.
The Peaceful betta, Betta imbelis (1,500 riels stamp) unlike other species of the genius Betta that we call fighting fish does not fight!