Gyrosigma acuminatum is a species of diatom in the genus Gyrosigma. The species was found in several different locations in Dickinson County, Iowa.
Gyrosigma acuminatum ranges from 77-153 üm in length and is typically 11-18 üm wide. It has distinct striae, with 16 to 18 transverse striae or 17-20 longitudinal striae in 10 micrometers. It is a pennate diatom.
The species is believed to be globally distributed in freshwater and has been observed in Europe, the United States, New Zealand, and South Africa.
Gyrosigma acuminatum lives in freshwater environments but has also been found in brackish water.