Arthropods

An arthropod is an invertebrate animal having an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda, which includes insects, arachnids, myriapods, and crustaceans.

Arachnid Arthropods - are a class of joint-legged invertebrate animals, in the subphylum Chelicerata. All arachnids have eight legs, although the front pair of legs in some species has converted to a sensory function.

Insect Arthropods - are by far the largest group of hexapod invertebrates within the arthropod phylum. Definitions and circumscriptions vary; in one approach insects comprise a class within the Phylum Arthopoda.

Crustacean Arthropods - Crustaceans form a large, diverse arthropod taxon which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill, woodlice and barnacles.