With around 10,000 species, lobsters and shrimps are among the largest group of crustaceans known as the decapods. Decapods, meaning "ten legs", are also the largest crustaceans in size. Lobsters and shrimps are of great importance to us both commercially and environmentally.

Lobsters and shrimps feature five pairs of legs with the first pair being heavier and usually having claws. The carapace is well developed and encloses the part of the body known as the cephalothorax. The rest of the body is known as the abdomen.