Snails have a bodily fluid known as hemolymph that is similar to blood. Hemolymph is found in many invertebrates and is believed to have scientific and pharmaceutical benefits.
Like other mollusks, snails have an open circulatory system. This means that their blood flow is not entirely contained within their blood vessels. Tulane University reports that the body mass contained beneath a snail's shell is packed with blood vessels.
Snail blood may have some significant scientific benefits for humans. Research performed by Ben-Gurion University and Clarkson University revealed that snail blood can actually conduct electricity, according to Engadget. The power of a snail may one day power listening devices for the Department of Homeland Security.
The blood of a snail is blue as a result of its blood pigment, haemocyanin. This pigment contains copper, which helps to give it a blue color. Human blood contains iron, which gives it a red color. The blood is colorless until it is oxygenated. Lobsters, crabs and spiders also have blue blood. According to PBS, biomedical engineers harvest the blue blood of horseshoe crabs for use in the pharmaceutical industry, and researchers are looking into which other blue-blooded creatures might have significant medical and pharmaceutical benefits.