What is the fluid that moves around in the circulatory system of a typical arthropod called?

The interstitial fluid is the fluid that moves around in the circulatory system of a typical arthropod. Arthropods have an open circulatory system, which pumps blood into a cavity called hemocoels that sorrounds the organs and then returns to the heart through ostia (openings). They contain hemolymph which is a mixture of blood and the interstitial fluid.