Eudiaptomus gracilis is characterized by its slender body shape, with the lateral expansion of the last thorax segment forming a slightly more prominent outer angle. Its furca is relatively short, about twice as long as it is wide, while the anterior antennas are long and slender, extending well beyond the furca, sometimes reaching up to the 4 or 5 outer joints. Typically, E. gracilis is highly transparent and nearly colorless, although in some instances, it may exhibit a broad transverse band of chocolate hue across the anterior division. Female: Typically measures between 1.0 to 2.0 mm in length. Male: Typically measures between 1.0 to 1.5 mm in length.