Some folks are squeamish at the sight or thought of blood. However, blood or blood-like systems for nutrient supply, waste removal, and defense against infection are some of the earliest shared features among all animal groups.
Much like the astounding diversity of species seen with the naked eye across invertebrates, fish, amphibians, reptiles, birds, and mammals, there is a corresponding diversity in their circulatory components seen microscopically (above left to right – blood from a Gray’s monitor, northern helmeted curassow, dromedary camel, and snow leopard).
Blood screens help us to understand the health of captive and free ranging animals. As a pathologist for the Wildlife Conservation Society’s Zoological Health Program based at the Bronx Zoo, I consider myself lucky to have a window into the world’s biodiversity on this additional ‘hidden’ level. Beauty is indeed more than skin deep.