What adaptations does the sand-worm have for breathing?

Sand-worms, or annelids, have specialized adaptations for breathing that include skin gills or a network of blood vessels beneath their skin, allowing for gas exchange directly through their moist epidermis. This adaptation enables them to absorb oxygen from the surrounding environment and release carbon dioxide efficiently. Additionally, their burrowing lifestyle ensures they remain in contact with moist soil, which is crucial for effective respiration.