10 animals with blue blood
The blue blood of the horseshoe crab is very useful to scientists. The hemocyanin present in it identifies bacteria and helps in testing medicines.
Octopus has 3 hearts and blue blood. These features keep it alive even in the low oxygen environment in the deep sea.
Squid is also like octopus, it has 3 hearts, in which blue blood containing hemocyanin flows. Its swimming system is very complex.
Spiders' blood is light blue in color and flows through an open circulatory system in their bodies.
Hemocyanin is also found in marine creatures such as shrimp, clams and scallops. They have blue blood and mostly live in cold, low-oxygen areas.
The blood of one particular species of frog appears blue not from hemocyanin, but from a bile pigment called biliverdin.