Distinguish between the followings (b) Septal nephridium and pharyngeal nephridium
Explanation Septal Nephridium: Septal Nephridium is the largest of the three types of nephridia. Septal nephridia are attached to the anterior and posterior surfaces of all the septa behind segment fifteen. These are present in two vertical rows on each surface of the septum, a row on either side of the intestine. Septal Nephridium opens into the supraintestinal excretory duct. Pharyngeal Nephridium: This Nephridium occurs in three pairs of the tuft on the side of the alimentary canal in the segments four to six. This Nephridium is closed as they lack nephrostome. The terminal ducts of the nephridia of each tuft unite to form a common pharyngeal nephridial duct. The common duct of the sixth segment opens into the buccal cavity, and the common duct of the fourth and fifth segment opens into the pharynx. Final answer Septal Nephridium is present on the anterior and posterior side of all the septa behind segment fifteen. These Nephridia open into the supraintestinal duct. Pharyngeal Nephridia is present in three pairs of tufts on the side of the alimentary canal from the segment fouth to six.
