Which structure forms a mucus-secreting cocoon during reproduction in many earthworms?

Which structure forms a mucus-secreting cocoon during reproduction in many earthworms?

• A. Clitellum
• B. Anterior
• C. Prostomium flap
• D. Posterior

Answer: (A)

The clitellum is the reproductive structure that secretes mucus to form a protective cocoon around eggs and sperm. During mating, this glandular, thickened band releases a mucus layer that becomes a slimy tube, picks up the eggs released by the female, and receives sperm from the male. As the worm moves, the clitellum slides off this mucus sleeve, creating a cocoon in which fertilization and development occur. The other options are not involved in cocoon formation: the anterior is the head end, the prostomium flap is a mouth-area flap, and the posterior is the tail end.

The clitellum is the reproductive structure that secretes mucus to form a protective cocoon around eggs and sperm. During mating, this glandular, thickened band releases a mucus layer that becomes a slimy tube, picks up the eggs released by the female, and receives sperm from the male. As the worm moves, the clitellum slides off this mucus sleeve, creating a cocoon in which fertilization and development occur. The other options are not involved in cocoon formation: the anterior is the head end, the prostomium flap is a mouth-area flap, and the posterior is the tail end.