Instead, hermit crabs have a hard exoskeleton on the front part of their bodies but a soft tail on the other half, which they protect using the discarded shells of other animals, like whelks.

Unlike other decapods such as shrimp, lobster, or crayfish, crabs’ tails are curled under the thorax (or midsection). The carapace (upper body shield) is usually broad, and as is common for the ...

The main features that a crustacean develops to become a crab include a wide, flat, rounded shell, and a folded, tucked-in ...

Horseshoe crabs also have 10 eyes—a pair of compound eyes on the front shell and more photo receptors along their tail. Horseshoe crabs’ bodies are divided into three segments. The head ...