Respiratory System of Spiders
WouterSpiders have a respiratory system similar to that of humans. While spiders require less oxygen than we do, they are capable of going days or even weeks without breathing. The type of respiration system that spiders use varies depending on species. Some have only book lungs, while others have both.
The spider’s respiratory system is simpler than that of humans, but still has four major components. The main parts of the respiratory system are the hemolymph, the trachea, the air film, and the plastrons. All of these work together to deliver oxygen to the internal organs of the spider. The hemolymph, which is similar to the blood of a spider, transports oxygen and waste carbon dioxide. The trachea, which are thin tubes lining the body, branch out from the book lungs. The air film provides a place for the exchange of carbon dioxide with water. The plastrons are tiny openings in the body that hold a thin layer of oxygen.
Some arachnids, such as mites, do not have book lungs. However, many arachnids do have tracheae. This network of narrow tubes is lined with a hard substance called chitin.
The trachea of spiders open directly to the surface through tiny holes. The slits are wide during activity, but closed during resting. In addition to the trachea, spiders also have physical gills. These spiracles are located on the abdomen. They hold a thin layer of oxygen around the tracheal system.
The tracheal system is thought to be a later development in the evolution of spiders.
