They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe.
If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
Earthworms breathe through their skin which contains mucus where the atmospheric air is dissolved. This dissolved air reaches the circulatory system which transfers oxygen to each cell in a random manner.
Earthworms breathe through their skin because for maintaining their surface body moist and slimy which is essential for their metabolic activities.
Therefore, it is well described above.
To learn more about Earthworm physiology, refer to the link:
https://brainly.com/question/20992190
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