cutaneous respiration in earthwormthe respiration

Question

Cutaneous respiration in earthworm.

1. The respiration performed by the skin is called cutaneous respiration 
2. In earthworm skin is the only organ of respiration.
3. The skin is richly supplied with blood vessels.In earthworm, the respiratory pigment (unlike other animals haemoglobin is dissolved in the plasma of blood but not in blood corpuscles) Haemoglobin carries oxygen to the tissues.
4. The skin is always kept moist because of the secretion of mucous & coelomic fluid which comes out through dorsal pores.
5. The oxygen present in the air diffuses into thin water layer which is beneath the mucous layer and then it diffuses into the blood through the walls of blood capillaries. In the same way carbondioxide expels out through the skin.
6. Earthworms come out of their burrows in rainy season when the burrows are filled with water due to suffocation.