Excretion in Earthworm: The excretory organs of earthworm consist of a large number of small glandular and sequentially arranged tubules called Nephridia. These nephridia are located in the body.
Each nephridium has a coiled excretory duct, which represents a simple excretory organ. The walls of these nephridia are glandular and richly supplied with blood vessels. The body cavity has a fluid, in which many waste products like ammonia and urea collect. These nephridia collect the waste products from the body cavity. The ciliary and muscular activity pushes the waste materials in the excretory tubules, from where it passes out of the body, through the outer pore. The earthworm has a circulatory system which carries blood to the body surface and is the main route for the removal of carbon dioxide, which is diffused out through the surface cells.
