Which one does not occur in Earthworm

Options

A. Septal nephridia
B. Macronephridia
C. Integumentary nephridia
D. Pharyngeal nephridia

Answer

To solve the question "Which one does not occur in Earthworm?", we will analyze the options provided and identify which nephredia type is absent in earthworms.

### Step-by-Step Solution:

1. **Identify the Types of Nephridia**:
- Begin by listing the types of nephredia mentioned in the question:
- Septal Nephridia
- Macronephridia
- Intubatory Nephridia
- Pharyngeal Nephridia

2. **Research Each Type**:
- **Septal Nephridia**: These are present in earthworms and are located in the intersegmental septum, particularly between the 15th and 16th segments.
- **Macronephridia**: This type is NOT present in earthworms.
- **Intubatory Nephridia**: These are also present in earthworms and are found in each segment starting from the 7th segment to the last segment.
- **Pharyngeal Nephridia**: These are present in earthworms, located in the 4th, 5th, and 6th segments, and are associated with a tuft that contains blood glands.

3. **Conclusion**:
- After analyzing all the types of nephredia, it is clear that the **Macronephridia** does not occur in earthworms.

### Final Answer:
The type of nephredia that does not occur in earthworms is **Macronephridia**.

---