Explain the dissection procedure of septal nephridia in earthworm.
Answers
The integumentary nephridia lie attached to the inner side of the body wall in all segments except the first two. The septal nephridia are attached to both sides of the septa behind the 15th segment. The waste in the coelom fluid from a forward segment is drawn in by the beating of cilia of the nephrostome.
ANSWER
The septal nephridia of the earthworm are the largest and are situated in four rows on the intersegmental septa in each segment behind the fifteenth. The terminal duct of septal nephridium is a short tube and many ducts open into a pair of septal excretory ducts situated along the septum in each segment. The septal excretory duct open and pour their contents into a pair of supra intestinal excretory duct. These longitudinal excretory ducts open into the lumen of the intestine.