WRITE A NOTE ON NEPHRIDIA..
Nephridia are segmentally arranged excretory organs present in earthworms.
On the basis of their location, three types of nephridia are found in earthworms. They are:
(a)Septal nephridia:These are present on both sides of the inter-segmental septa behind the 15thsegment. They open into the intestines.
(b)Integumentary nephridia:These lie attached to the body wall from the third segment to the last segment, which opens on the body surface.
c)Pharyngeal nephridia: These are present as three paired tufts in fourth, fifth, and sixth segments.