American House Spider (Parasteatoda Tepidariorum)
The American house spider is indigenous to most of North America. This spider has an open circulatory system. Its blood system contains a heart, veins, and arteries, however, it does not contain capillaries. The heart of the spider is located in the back of the abdomen. The heart has valves that keeps the blood flow in one constant direction. The heart of spider pumps blood into a body cavity and it circulates to other organs. The heart also has its own nervous center. This allows the heart to beat independently. The blood of the spider is blue because of the presence of hemocyanin. Hemocyanin is a protein that is responsible to transport oxygen, nutrients, and hormones around the blood. It is not stored in a cell, but it circulates freely in the blood. The spider receives the oxygen it needs to survive because of the haemocyanin protein moving through the blood. The blood of the American house spider also raises the blood pressure of the spider when it sheds old skin or when the spider stretches its legs. |