Enjoy a closer look at the incredible diversity of life with which we share this planet.
87 imagesThese invertebrate [no-backbone] animals make up more than 80% of all known living species. Arthropods includes such diverse organisms as fleas, crabs, butterflies, and spiders. The versatile body-plan of arthropods is based on repeating segments, each with a hard outer layer, within which lie the softer organs. Some of the segments bear appendages such as legs, antennae, gills, and mouth parts. The smallest arthropods weigh less than 25 micrograms [less than one miionth of an ounce], while the legs of a Japanese spider crab can span about 4 meters [over 13 feet].