Octopus: Octopus blood is blue due to hemocyanin, which is more efficient in cold, low-oxygen environments.
Horseshoe Crab: Their blue blood contains copper-based hemocyanin and is highly valued for detecting bacterial endotoxins.
Brachiopods: These marine animals have purple blood due to a pigment called hemerythrin, used for oxygen transport.
Icefish: Icefish have clear blood because they lack hemoglobin, adapting to oxygen-rich Antarctic waters.
New Guinea Lizard: Their green blood comes from high levels of biliverdin, a bile pigment, which might offer protection from malaria.
Leech: Leeches have greenish blood due to chlorocruorin, a pigment similar to hemoglobin but with a different iron composition.