Do Spiders Have Hearts?
WouterSpiders don’t have the same heart and blood system that most animals have. Instead, they have a simple circulatory system based on tracheae. These tiny, hard-plated organs conduct air directly to various tissues.
The spider circulatory system includes hemolymph. This blue, liquid-like substance provides oxygen to the body’s tissues. It also transports nutrients and chemicals, and is vital for the primary functioning of the spider’s organism.
Hemolymph, however, doesn’t contain the proteins of red or white blood cells. Instead, it contains molecules of hemocyanin, which function similarly to the hemoglobin in the blood. They bind to copper atoms and diffuse into cells that need oxygen.
The hemolymph serves as a replacement for the spider’s blood. It is pumped into the spider’s veins, which then carry it to the body’s sinuses and cavities. Without it, the spider’s body would be unable to function.
The spider circulatory system is a good example of how species adapt. Because the spiders’ body has no space for complex cardiovascular structures, they have developed a system of arteries and veins that move oxygen into the body and out through simple diffusion.
As with most other animals, the heart is important. A spider’s heart produces a regular, one-way flow of blood that flows from the abdomen to other parts of the spider’s body. An open circulatory system, like the spider’s, moves the hemolymph at a slow rate, which allows the oxygen to maintain an even supply throughout the body.
