How Does a Cockroach Get Blood?
WouterThe first thing you should know about cockroaches is that they don’t have red blood. Instead, their blood is clear, yellowish, or orange. This is because cockroaches don’t use hemoglobin to transport oxygen. Instead, they use tracheae to bring oxygen to their cells and remove carbon dioxide from the tissues. In addition, their blood color depends on several other factors. For example, if you were to look at a cockroach female who is producing eggs, her blood is a light orange color because she is carrying a protein called vitellogenin. This protein is transported from the liver to the ovary where it carries a carotenoid molecule that is needed for the development of the embryo.
Although cockroaches can bleed when their head is lost, they do not bleed much. Their open circulatory system, which includes hemolymph instead of veins and capillaries, means that their blood doesn’t circulate under pressure like ours does. Because of this, cockroaches’ blood sloshes around in their tissues and doesn’t flow like ours.
Another misconception about cockroach blood is that the insects don’t bleed when they die. Instead, they produce a yellow or orange fluid, known as hemolymph. This fluid attracts more roaches. However, cockroach blood doesn’t contain any red blood cells at all. Instead, it is composed of proteins and vitamins that carry oxygen.
