Penaeus semisulcatus has a pale brown body which sometimes shows a greenish tint on the carapace with two yellow or cream tansverse bands across the back of the carapace. The abdomen is banded with brownish grey and pale-yellow transverse bands, while the antennae are banded brown and yellow. It has a uniformly smooth carapace and abdomen. The rostrum has seven or eighy dorsal teeth and three ventral teeth. The atrodrostral crest and groove, the carina, extends beyond the epigastral tooth with the postrostral carina almost reaching to the rear of the carapace.