Recognize that all organisms are composed of cells and that many organisms are unicellular and must carry out all life functions in one cell. 3.1.6.A5 Describe basic structures that plants and animals have that contribute to their ability to make or find food and reproduce.
Crabs are crustaceans and all crustaceans belong to the taxonomic domain of Eukarya, which are characterised by having cells with nuclei. Eukarya covers all organisms in the Kingdom Animalia, as well as the Kingdoms Plantae, Fungi and Protista.
Horseshoe crabs belong to the phylum of Arthropods, which consists of animals having an articulated body and limbs. The three major classes of Arthropods are Insects, Arachnids and Crustaceans. The horseshoe belongs to its own class called Merostomata, which means legs attached to the mouth..