Petromyzon is/shows

Options

A. A gnathostome
B. A marine animal
C. Anadromous migration
D. Both (2) & (3)

Answer

To answer the question about Petromyzon, we will analyze the options provided and determine which characteristics apply to this organism.

### Step-by-Step Solution:

1. **Understanding Petromyzon**:
- Petromyzon is a genus that belongs to the class Cyclostomata, which includes jawless fish known as lampreys.

2. **Analyzing Option A - Gnathostome**:
- Gnathostomes are vertebrates that possess jaws. Since Petromyzon is jawless, this option is incorrect.

3. **Analyzing Option B - Marine Animal**:
- Petromyzon is primarily found in marine environments. Therefore, this option is correct.

4. **Analyzing Option C - Anadromous Migration**:
- Petromyzon exhibits anadromous migration, meaning it migrates from the ocean to freshwater to spawn. After spawning, the adults typically die, and the larvae return to the ocean. This option is also correct.

5. **Analyzing Option D - Bone**:
- Petromyzon does not have a bony structure; instead, it has a cartilaginous skeleton. Therefore, this option is incorrect.

6. **Conclusion**:
- The correct answers are options B (marine animal) and C (anadromous migration).

### Final Answer:
Petromyzon shows characteristics of being a marine animal and exhibiting anadromous migration. Therefore, the answer is both option B and option C.

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