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.
The horseshoe crab (also known as the king crab), is a hard-shelled invertebrate found on the sea floor in warmer climates. Despite it's name, the horseshoe crab is not actually a crab (or crustacean) and is in fact more closely related to arachnids such as spiders and scorpions.he horseshoe crab has a hard outer shell, five pairs of legs and a long, thin tail which the horseshoe crab uses for changing direction whilst swimming rather than as a defensive weapon.