A horseshoe crab has been around for almost 500 million years. They are classified as arthropods and not actual crabs. However, There are many reasons that have helped them survive this long including, they can eat almost any organic matter. There blood is different from normal, in fact it’s blue. This blood helps them heal any wounds right away. They can also live in areas with very low levels of oxygen, meaning habitat is not a big issue for them. Evolution has also helped them grow and adapt seeing as they’ve survived this long.
