Thai river sprat
Thai river sprat (Clupeichthys aesarnensis) is a small, herring-like fish found only in the Mekong River basin of Indochina. It has a slender, almost transparent body with a pale yellow tint and a silver stripe along the middle. The head is slightly darker with a greenish hue. Most individuals reach about 4 cm, with some up to 6 cm long.
In Thailand, it lives mainly in Isan, especially in large reservoirs such as Ubol Ratana Dam, Lam Pao Dam, Sirindhorn Dam, and Sirikit Dam. It forms large schools near the surface and midwater in slow-moving or still waters.
The fish feeds mainly on insects and zooplankton, catching insects by leaping from the surface. It is usually harvested at night using lift nets and lights. The Thai river sprat is widely eaten and is an important local fish in Isan, used in fish sauce, dried fish, and fermented fish.
It has been introduced to reservoirs in Malaysia and Indonesia, where it also supports local fisheries. Local Thai names include siu kaew (glass minnow) and taep kaew (sword glass minnow).
Conservation status: Least Concern.
This page was last edited on 3 February 2026, at 00:51 (CET).