Diaphanosoma brachyurum is characterized by its oval shape, being approximately twice as long as it is broad. Its head constitutes about one-third of the total body length. Notably, this genus lacks a rostrum, a distinguishing feature. At the front of the head, there is a large compound eye, and the head itself has a rounded appearance. The second pair of antennae is exceptionally long, extending beyond the tip of the abdomen. These antennae are equipped with bristles along nearly the entire length of one margin. The postabdomen is relatively small and slender, featuring three coarse denticles attached to the abdominal claw. The basal denticle is roughly half the length of the last one. Diaphanosoma brachyurum is almost transparent or may have a light yellow coloration. In terms of size, females typically range from 0.6 to 1.3 mm in length, while males are generally smaller, with a length of 0.6 to 0.9 mm.