This gentle marine crab that can live for up to 100 years is all crab. While both spiders and Japanese spider crabs are both Arthropods, spiders are not crustaceans. The related link listed below...
It depends on the species of crab, but the most common type that are served in restaurants and such are usually an orange-reddish color. Crabs are a variety of colors. Many crabs are orange and white...