Which of the following is not true to open type of circulatory system?

The statement "Absence of blood capillaries" is not true for an open type of circulatory system. In an open circulatory system, there are blood vessels, but the blood directly bathes the organs and tissues in open spaces called sinuses. While there might be a heart, it's not as compartmentalized as in closed circulatory systems, and blood doesn't always travel through defined capillaries.