What is the Difference between crustacean arachnid and centipedes millipedes?

Crustaceans, arachnids, centipedes, and millipedes are all arthropods, but they belong to different subphyla and classes. Crustaceans (like crabs and lobsters) are primarily aquatic and have gills, while arachnids (like Spiders and scorpions) have eight legs and typically do not have antennae. Centipedes are fast-moving predators with one pair of legs per body segment, whereas millipedes are slower detritivores with two pairs of legs per segment, primarily feeding on decomposing organic matter. Each group has unique adaptations and ecological roles within their environments.