AI Insight
Animal blood comes in multiple colors beyond red, including blue, green, and white, due to different oxygen-carrying molecules than the hemoglobin found in humans. While hemoglobin contains iron and appears red, some creatures use copper-based hemocyanin which appears blue, and others have different pigments or proteins. Antarctic icefish are unique among vertebrates in completely lacking red blood cells, instead dissolving oxygen directly in their plasma.
Why it matters
Understanding diverse blood chemistry across species provides insights into evolutionary adaptations to extreme environments and different metabolic strategies. This knowledge could inform biomedical research, including the development of blood substitutes and treatments for oxygen-transport disorders.
Understand the Science
The hemoglobin in humans’ blood is not the standard for all critters—and one group of Antarctic fish are the only vertebrates to not have red blood cells at all