Choose the structure located in pre clitellar region with respect to reproduction 

Options

A. a. Male gonopore
B. b. Female gonopore
C. c. Spermthecal apertures
D. d. All

Answer

To solve the question regarding the structure located in the pre-clitellar region with respect to reproduction in earthworms, follow these steps:

### Step-by-Step Solution:

1. **Understand the Terminology**:
- The term "pre-clitellar region" refers to the segments of the earthworm that are located before the clitellum. The clitellum is a thickened, glandular section of the body wall that is involved in reproduction.

2. **Identify the Clitellum**:
- The clitellum in earthworms is typically found in segments 14 to 16. Therefore, the pre-clitellar region would include segments 1 to 13.

3. **Locate the Relevant Structures**:
- In the pre-clitellar region (segments 1 to 13), we need to identify structures related to reproduction.

4. **Identify the Spermatical Apertures**:
- The spermatical apertures, which are openings that allow for the transfer of sperm, are located in segments 5 to 9. There are four pairs of these apertures in this region.

5. **Differentiate Between Structures**:
- The female genital pore is located in the clitellar region (segment 14), while the male genital pore is found in the post-clitellar region (segment 19). Thus, they are not located in the pre-clitellar region.

6. **Conclusion**:
- Based on the information gathered, the structure located in the pre-clitellar region with respect to reproduction is the **spermatical apertures**.

### Final Answer:
The structure located in the pre-clitellar region with respect to reproduction is the **spermatical apertures**.

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