¿Por qué es roja la sangre?

The video explores the different colors of blood in various animals. It explains that while many assume all blood is red, this is not the case. Horseshoe crabs have blue blood due to hemocyanin, earthworms have pink blood because of emeritrin, and humans have red blood due to hemoglobin. Hemoglobin is highlighted as the most effective oxygen transporter, making red the most common blood color in the animal kingdom.

What new insight or understanding did you gain from this video?