Their ten walking legs, and their split nature (biramous). All their legs are tiny pincers matching the main ones, unless the segment is fused.
the endoskeleton
Crustaceans differ from other arthropods in that they have biramous (two-part) appendages and the nauplius larval form.
Crustaceans are distinguished from other arthropods in that their appendages are biramous (branch into two parts), and that they have a larval form which has a single eye and antennae used for swimming (nauplius). One might also assume they differ from most other arthropods in that they are aquatic, but there are both aquatic non-crustaceam arthropods (like the horseshoe crab and the sea spider), and non-aquatic crustaceans (like the terrestrial woodlouse). Note that the term "anthropod" should not be confused with arthropod - the former is a broad term and not a taxon, meaning human or human-like.
Roundworms (Nematoda) are related to arthropods because they both molt.Note; Crustaceans are arthropods. :P
Arachnids differ from other arthropods in that they have no antenna (nor wings, like many insects). They also use book lungs to breathe, rather than the gills or spiracle/trachea configuration. They have a body plan of only two sections (tagmata) and eight legs, although often with a modified forward pair different from most other arthropods.
you know stuff and like other stuff
Arthropods are in the Kingdom Animalia. They belong to the phylum Arthropoda, which includes insects, spiders, crustaceans, and other related groups.
Tarantulas and other spiders are classified as arthropods by virtue of their physical characteristics. In taxonomic classification arthropods branch into two major subcategories, the chelicerates which include arachnids, and the mandibulates which includes the myriapods, crustaceans and insects. These all share the broad definition of arthropoda which is characterized by joint appendages and possession of an exoskeleton.
Uranus is tilted on it's side other than the other planets.
No, worms are not arthropods. Arthropods are invertebrates with an exoskeleton, segmented body, and jointed appendages, such as insects, spiders, and crustaceans. Worms, on the other hand, are soft-bodied invertebrates belonging to phyla such as Annelida or Nematoda.
The three main classes of arthropods are: insects (cockroachs, ants, flies, bees, beetles, butterflies), crustaceans (crabs, lobsters, shrimps, barnacles) and arachnids (scorpions, spiders, mites). Other classes are onychophorans (velvet worms), diplopods (millipedes) and chilopods (centipedes).
Bees are classified as arthropods because of their characteristic segmented bodies, an exoskeleton made from chitin, and joint appendages.