The Farsi toothcarp (Esmaeilius persicus) is a species of pupfish belonging to the family Aphaniidae.

It is endemic to the Maharloo Lake Basin in Iran, residing in springs, lagoons, and marshes containing fresh to brackish water.

[1][2] The species name, persicus, refers to Persia, the ancient name of Iran, where the fish is found.

Females have numerous alternating light and dark bars, which gradually merge with the pigmentation on the rest of their bodies.

The caudal fin spot has been recorded to be elongate, oval, or teardrop-shaped, but is almost always in the form of a lozenge.