Some of the more advanced species have segments fused together to form regions called the head, thorax, and abdomen. The bodies of arthropods are encased in a shell-like exoskeleton. Many arthropods have compound eyes. Air from the outside goes through the tracheae by going through the special openings called spiracles. The arthropod circulatory system is open, with a heart along the top of the body that squeezes blood out into internal body spaces.
Terrestrial arthropods have an excretory system that conserves water and eliminates waste.
Insects, the most abundant of the arthropods have wings. Not endangered animals, endangered arthropods. You may have thought that only mammals, birds, reptiles, and amphibians could go on the endangered species list, but I am here to tell you that there are plenty of arthropods that are on the list too. These include arthropods like the American Burying Beetle. This guy is dying because of the increased use of pesticides.