Movement of coelomic fluid helps in locomotion of

Options

A. Hydra
B. Frog
C. Starfish
D. Earthworm

Answer

**Step-by-Step Solution:**

1. **Understanding Coelomic Fluid**: Coelomic fluid is a fluid found in the coelom (body cavity) of certain animals. It plays a crucial role in locomotion for some organisms.

2. **Identifying Organisms**: The question lists four organisms: hydra, frog, starfish, and earthworm. We need to determine which of these uses coelomic fluid for locomotion.

3. **Locomotion Mechanisms**: Different animals have various mechanisms for locomotion:
- **Hydra**: Uses a combination of muscle contractions and water movement.
- **Frog**: Primarily uses muscular limbs for jumping.
- **Starfish**: Uses tube feet and water vascular system for movement.
- **Earthworm**: Uses coelomic fluid along with muscle contractions for movement.

4. **Focus on Earthworm**: The earthworm's locomotion involves the contraction and relaxation of its body muscles, a process known as peristalsis. The coelomic fluid aids in this process by providing a hydrostatic skeleton, allowing the earthworm to move through soil.

5. **Additional Mechanisms**: Earthworms also have bristle-like structures called setae that help anchor them to the ground, facilitating movement as they contract and relax their muscles.

6. **Conclusion**: Based on the analysis, the movement of coelomic fluid significantly aids in the locomotion of the earthworm.

**Final Answer**: The movement of coelomic fluid helps in locomotion of the earthworm.

---