A network of tubules spread throughout the body supply air in
Insects have a network of tubes (tracheal tubes) to transport atmospheric air within the body. Some other terrestrial arthropods like spiders and scorpions have book lungs. Special vascularized structures called gills (branchial respiration) are used by most of the aquatic arthropods and molluscs whereas vascularised bags called lungs (pulmonary respiration) are used by the terrestrial forms for the exchange of gases. Terrestrial annelids like earthworms have moist cuticle for gas exchange.