The Espe’s Rasbora Trigonostigma espei (previously Rasbora espei) was described by Meinken in 1967. It is found in Southeast Asia throughout the eastern slopes of the Gulf of Thailand in the countries of Cambodia and Thailand, and a recent population was also found on the Island Phu Quoc of Vietnam.

This species is listed on the IUCN Red List as Least Concern (LC). Although trade has some impact on the populations, it is considered stable. Other common names it is known by include Lambchop Rabora, False Harlequin, Narrow Wedge Harlequin, Slim Harlequin, Rasbora Espei, and Espei Rasbora.