Rag worms
The rag worm is a marine based, segmented worm found all around the world. Rag worms are primarily omnivorous. They are commonly used as bait for fishing. Rag worms perform similar respiration processes to the earthworm and leech, as they do not contain a formal respiratory system. Gases are exchanged through the skin; oxygen enters the body while carbon dioxide, among other waste products, exit. This occurs all over the body of the rag worm.