The common general morphological characteristics of all arthropods include:

(1) Segmented bodies.

(2) An exoskeleton; that is, an external skeleton. The skeleton is on the outside of the animal, not the inside.

(3) Jointed appendages - such as legs and antennae. Remember, this gives them their name (from the Greek arthros=jointed, poda=foot).

(4) Bilateral symmetry, a type of body organization in which the body can be divided into two equal halves by a single line down the middle of the body.

Internally all arthropods have:

(5) A ventrally located nerve cord. Ventral is the opposite of dorsal and means toward the belly.

(6) A dorsal blood vessel.

Question to think about: How does this basic body plan differ from vertebrates?