Serranus tortugarum has a laterally compressed elongate body with a pointed snout which is shorter than the diameter of the eye.

There is a row of 2-3 pale blotches on the flanks and the colour of the fins varies from transparent to pinkish.

It is a synchronous hermaphrodite, this means that each fish has both male and female reproductive organs at the same time.

[5] They frequently hover over sandy or rubble areas of seabed and use a nearby conch shell for shelter.

[6] Serranus tortugarum was first formally described in 1935 by the American biologist William H. Longley (1881-1937) with the type locality given as the Tortugas Islands in the Florida Keys.