Why is Spiders Blood Blue?
WouterIf you’ve ever been under a spider’s spell, you might have wondered what it’s blood is. Well, not all spiders have blue blood. But, there are some species of octopi, slugs and crustaceans that do.
Hemocyanin is a protein that gives spiders and other arthropods their blue color. It is a bigger protein than other blood proteins. It is also an oxygen-binding protein.
Hemocyanin is also found in a number of other organisms, including snails and slugs. In fact, some marine worms have an oxygen transport protein that gives their blood a greenish-blue hue.
Another interesting feature of spiders is their open circulatory system. They have small tubes running into their bodies that carry blood and hormones. These blood-filled tubes are used for local purposes such as transporting nutrients, circulating oxygen and shedding old skin.
Some spiders have small veins running through their body that are the same colour as their blood. Some of these tiny veins are actually used for chemical warfare. This is because they contain a substance called a polypeptide that prevents loss of essential signals.
The colour of spiders’ blood is a pale blue due to the copper based haemocyanin that binds oxygen. The protein has 24 subunits, the largest of which consists of a copper atom.
It isn’t clear how the copper atom in the hemocyanin molecule is able to turn the liquid into a blue color. It probably has to do with the way the molecule reflects light.
