This species is found in the western Indian Ocean and the Red Sea.

The halfspined flathead was first formally described as Platycephalus prionotus in 1873 by the French zoologist Henri Émile Sauvage with its type locality given as the Red Sea, or possibly Madagascar.

[4] The halfspined flathead has an elongated body with a flattened head with obvious ridges on the upper and lower parts of the operculum.

The vomerine and palatine teeth are arranged in parches on either side of the roof of the mouth.

[2] The halfspined flathead occurs from Maputo Bay north to the Red Sea and east to the Persian Gulf and Karachi.