Question

Earthworm burrow underground by the means of waves of muscular contraction. Which structure helps in movement and in holding the soil?

• A. Parapodia
• B. Setae
• C. Chaetae
• D. Both (a) and (b)

Answer 1

Answer: (D)

Both (a) and (b)

Parapodium - one of a pair of fleshy appendages of a polychete annelid that functions in locomotion and breathing

Polychaetes have several means of locomotion. When crawling slowly, they use the parapodia much like legs to propel themselves over their substrate. Thus, the parapodia have a dual function, the upper part being a respiratory organ, and the lower part a propulsive one.

A seta is a stiff hair, bristle, or bristle-like process or part of an organism. The plural form is setae. Setae help earthworms attach to the surface and prevent backsliding during peristaltic motion.