Earthworm body is covered externally by a thin, non-cellular layer called

Options

A. Body wall
B. Epidermis
C. Coelomic epithelim
D. Cuticle

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks what the external thin non-cellular layer covering the body of an earthworm is called.

2. **Identifying the Options**: The options provided are:
- Body wall
- Epidermis
- Coelomic epithelium
- Cuticle

3. **Analyzing the Options**:
- **Body Wall**: This term generally refers to the entire outer layer of the organism, not specifically a non-cellular layer.
- **Epidermis**: This is a cellular layer that lies beneath the cuticle and is involved in various functions, including secretion.
- **Coelomic Epithelium**: This refers to the lining of the coelom (body cavity) and is not the external layer.
- **Cuticle**: This is a thin, non-cellular layer that covers the body of the earthworm externally.

4. **Conclusion**: The correct answer is the cuticle, as it serves as a protective layer that prevents drying and protects against abrasion from soil particles.

5. **Importance of Cuticle**: The cuticle is moist, allowing for cutaneous respiration, where oxygen diffuses through it into the blood vessels beneath. This is crucial for the survival of earthworms as they respire through their skin.

6. **Final Answer**: The earthworm body is covered externally by a thin, non-cellular layer called the **cuticle**.

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