The Greater Argonaut (Argonauta argo) is a cephalopod with a blue sheen on their pair of arms and around their eyes. 6 of their 8 arms are long and thin while the other 2 are rounded into palms that can be spread. The females of this species are much larger than the males. Female Greater Argonaut’s use the 2 arms for form a delicate shell that she uses to protect her babies while they are young. The Greater Argonaut can be found in tropical and subtropical waters around the world. Greater Argonauts generally eat sea slugs and crustaceans. They are not in danger of extinction.