Question

Earthworms have no skeleton but during burrowing, the anterior end becomes turgid and acts as a hydraulic skeleton. It is due to the

• A. coelomic fluid
• B. blood
• C. gut peristalsis
• D. setae

Answer 1

The correct option is A coelomic fluid

A fluid filled cavity present between the gastrointestinal tract and body wall is called a true coelom. The fluid present inside the coelom is called coelomic fluid. Coelomic fluid contains water, salt and some proteins. It is due to the coelomic fluid that the skeleton of earthworm becomes turgid in the anterior side and acts as a hydraulic skeleton.
The contraction and relaxation of the gut is known as gut peristalsis.
Setae are S-shaped structures present in the epidermal pits of the earthworm. The primary role of setae is locomotion. The fluid that runs in the circulatory system, blood, plays no role in burrowing.