Question

Pharyngeal nephridia of earthworm Pheretima occur in segments

• A. 3, 4 and 5
• B. 4, 5 and 6
• C. 5, 6 and 7
• D. 6, 7 and 8

Answer 1

The correct option is B 4, 5 and 6

Pharyngeal nephridia lie in three paired tufts, one on either side of the anterior region of the alimentary canal in the segments 4th, 5th, and 6th. The tufts of pharyngeal nephridia also contain blood glands.

Each pharyngeal nephridium is about the size of a septal nephridium but it is of the closed type having no funnel or nephrostome. It has a short straight lobe and a spirally twisted loop, its lumen has ciliated canals.

So the correct answer is '4th,5th and 6th segments'.