Structure

     Penaeus setiferus have an exoskeleton.  The body is divided into two parts, the abdomen and the cephalothorax.  The abdomen or tail has five pairs of appendages used for movement.  The Cephalothorax or head region of the shrimp contain the digestive, circulatory, reproductive, and nervous systems.  Arthropods have an open circulatory system, meaning that their blood and lymph are combined as they flow throughout the body.  This is called hemolymph.  Shrimp have a compact single chamber heart with three Ostia. Ostia are openings in the walls of the heart that allow blood to flow into the heart.  They also have small ‘accessory hearts’ to circulate blood throughout the body.  Shrimp also have a brain that receives messages from the eyes and antennae.  The nerves also provide movement to the appendages, tail, and mouth.  Many of these cool structural features are advantageous to the shrimp during reproduction. 

Shrimp found at http://ccmaserver.nos.noaa.gov/products/biogeography/efh/gom-efh/fl.shtml