Arthropods characterization-morphology-symmetry-germ layers

Question

According to examples of representing beings, how are arthropods characterized, fundamental morphology, kind of symmetry, germ layers and coelom, respiratory system, digestive system, excretory system, circulatory system, nervous system and kinds of reproduction?

Answer 1

Illustrations of representing beings: cockroaches, crabs, lobsters, flies, shrimps, spiders, scorpions and mites. Fundamental morphology: segmented body (or metameric), articulated limbs, periodic ecdysis and chitinous exoskeleton. Kind of symmetry: bilateral. Germ layers and coelom: triploblastics and coelomates. Digestive system: complete. Respiratory system: tracheal in insects, branchial in crustaceans, tracheal and book lungs in arachnids. Circulatory system: open, hemocyanin in arachnids and crustaceans. Excretory system: malpighian tubules in insects, malpighian tubules, green glands incrustaceans and coxal glands in arachnids. Nervous system: ganglial. Kinds of reproduction: sexual, with or without larval phase in insects and crustaceans, metamorphosis in various insects, no larval phases in arachnids.