Arthropods are a member of a diverse group of animals such as insects, scorpions, spiders, crustaceans, and centipedes. Arthropods have 5 distinguishable characteristics that set them apart from other animals; Exoskeletons, segmented bodies, jointed appendages, bilateral symmetry, and an open circulatory system.
Arthropods have no internal skeletal system. Instead, they have an exoskeleton made of chitin to protect them. Their bodies are segmented into sections. Some arthropods have sections, while others have hundreds. They have jointed appendages, which allow for flexibility and movement. The joints generally only bend in one direction. Bilateral symmetry means that their body can be divided into two sections from top to bottom and have two symmetrical pieces. The left side is symmetrical to the right. Arthropods do not have a network of veins. Instead, their blood is pumped though an open circulatory system called sinuses.