Prawns

Prawns are decapod crustaceans, belonging to the sub-order Dendrobranchiata.^[3] The term "prawn" is also used in various contexts for other animals, especially caridean shrimp.^[4] They are found worldwide and include commercially significant species, such as the whiteleg shrimp Litopenaeus vannamei, Atlantic white shrimp Penaeus setiferus, Indian prawn Fenneropenaeus indicus and tiger prawn Penaeus monodon.

Crabs

True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (Greek: βραχύς / brachys = short,^[2] οὐρά / οura = tail^[3]), or where the reduced abdomen is entirely hidden under the thorax. Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs and crab lice – are not true crabs.