Snakes, with their diverse forms and intriguing behaviors, often prompt questions about their basic biology. Among these inquiries, a common one pertains to the color of their blood, a fundamental aspect of their internal workings.
The True Color of Snake Blood
The blood of a snake is red, a characteristic shared with most other vertebrates. The shade of red can vary depending on its oxygen content. When rich with oxygen, typically as it leaves the lungs and circulates through the body, it appears a bright, vibrant red. Conversely, blood that has delivered its oxygen to tissues and is returning to the lungs for re-oxygenation will be a darker, less vibrant red, sometimes appearing maroon.
The Biological Basis of Blood Color
The red color of snake blood comes from hemoglobin, a protein found within their red blood cells. Hemoglobin contains iron atoms; their interaction with oxygen produces the characteristic red coloration. Each hemoglobin molecule can bind to multiple oxygen molecules, acting as the primary transporter of oxygen from the lungs to various tissues throughout the snake’s body.
When oxygen binds to the iron in hemoglobin, it causes the blood to appear bright red. As oxygen is released to the body’s cells, the hemoglobin changes its structure, resulting in a darker red hue. This process is fundamental to all vertebrates, which utilize hemoglobin for oxygen transport and possess red blood. Snake blood, like that of other vertebrates, is composed of red blood cells, white blood cells, platelets, and plasma.
Clarifying Common Misconceptions
Despite their diverse appearances and habitats, snakes universally possess red blood, a fact that sometimes contradicts popular belief. One common misconception confuses a snake’s blood with its venom. Snake venom is a complex mixture of proteins and enzymes, which can appear yellowish or clear, but it does not change the snake’s own blood color.
Another misunderstanding stems from the vast array of colors and patterns found on snake skin. A snake’s external coloration, which can range from vibrant greens and yellows to dark browns and blacks, has no bearing on its blood color. The color of dried blood, which can appear brownish or blackish, might also lead to false assumptions about its original hue. While some invertebrates, such as octopuses or horseshoe crabs, have blue blood due to copper-based hemocyanin, and certain lizards have green blood from biliverdin, snakes, as vertebrates, consistently have red blood.