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 Giant Spider Crabs, Slipper Lobsters, Horseshoe Crabs and various shrimp.