This fish is native to rivers, estuaries and lagoons opening into the Gulf of Thailand, also in the Mekong Basin and in rivers of southern Borneo, Indonesia. It can grow to 2-3/4 inches, but the photo specimen was 2.16 inches. Largest in the batch was a giant, 2.4 inches long.
These fish are extremely delicate, and it was difficult for me to find a specimen in the tray without its belly burst open. I did not try to extend the pelvic fins, which you can see the tips of at the back end of the belly, for fear of bursting it open.
More on the Herring Family
The main use for these fish is to make Prahoc, a fermented fish sauce, usually made from fresh water fish.