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.
Even though the horseshoe crab has a hard shell and numerous appendages with claws, it is not really a crab. Horseshoe crabs belong to the phylum, Arthropoda, along with crabs, insects, and other invertebrates with jointed legs, but their closest living relatives are spiders and scorpions.True crabs have two pairs of antennae and a pair of mandibles, or jaws; horseshoe crabs lack these structures.nit Five COAST/Horseshoe Crabs ïProject Oceanography Fall 2001 82 with claws. In adult males, the second pair of claws (pedipalps) has a âboxing-gloveâ appearance and is used to grasp females during spawning. Horseshoe crabs also have four simple eyes on the top of their carapace instead of two as with the true crab.