Transport Systems. Transport Systems. What type of organisms have transport systems? Why do organisms need a transport system?. Insects. Insects don't have veins or arteries, They do have circulatory systems. An open circulatory system.
A single blood vessel runs along the dorsal side of the insect, from the head to the abdomen.
Insect blood is only about 10% hemocytes (blood cells); most of the hemolymph is watery plasma.
In the anterior region of the worm, there are five pairs of vessels, which we loosely term "hearts," that connect the dorsal and the ventral vessels.