Question

Which of the following statements is true for Pheretima?

• A. It is a dioecious animal with distinct sexual dimorphism.
• B. In it, copulation occurs at night in burrow during rainy season.
• C. It can copulate throughout the year whenever it rains.
• D. It cannot travel both backwards and forwards.

Answer 1

The correct option is B In it, copulation occurs at night in burrow during rainy season.

• Mating occurs usually when the ground is wet following rain. Earthworms may emerge and travel over the surface of the ground before they mate, but most often they merely protrude the anterior end and mate with a worm in an adjacent burrow.
• The two worms join the lower surfaces of their anterior ends, with heads pointing in opposite directions. Mucous is secreted until each worm is enclosed in a tube of slime. When the sperm is released, it is carried backward in longitudinal grooves that are converted into tubes by the mucous sheath to the sperm receptacles of the mating partner.
• The worms then separate and egg-laying and fertilization occur later.