Anthropodas are invertebrate animals that have an exoskeleton, a segmented body, and jointed appendages. Anthropods are members of this phylum, and it includes insects, aquatic creatures, and arachnids. The body of these organisms consists of repeated segments, with repeated pairs of appendages on each segment. Anthropods’ primary internal cavity is called a hemocoel, which contains the internal organs. They have an open circulatory system, with a “ladder-like” nervous system. This phyla is in the Sub-Kingdom Eumetazoa, and are classified as Bilateria.