Use of dorsal carinal spines to differentiate between postlarvae of brown shrimp, Penaeus aztecus Ives, and white shrimp, P. setiferus (Linnaeus).

The presence of spines on the dorsal carina of the sixth abdominal segment of postlarval brown shrimp distinguished them with almost one-hundred percent reliability from postlarval white shrimp, in field collections from the tidal pass at Galveston, Texas.