Arthropods are invertebrates with an exoskeleton, a hard and protective outer shell made of chitin. They also have appendages that are jointed and their bodies are segmented.

An exoskeleton is rigid and cannot expand to allow the animal to grow, so the animal must regularly molt to get rid of the smaller exoskeleton and replace it with a larger one.

Arthropods can be found on land, in the water and in the air. Some examples of arthropods you will find at the Newport Aquarium are Puget Sound King Crabs, Caribbean Spiny Lobsters, Hermit Crabs, Decorator Crabs, Fire Shrimp, Sally Lightfoot Crabs, White Crayfish and various other shrimp.