Cyclostomata belongs to which division?

Options

A. Pisces
B. Agnatha
C. Acraniata
D. Tetrapoda

Answer

**Step-by-Step Solution:**

1. **Understanding Cyclostomata**: Cyclostomata is a class of jawless fish, which includes organisms like lampreys and hagfishes. They are characterized by their lack of jaws and have a unique mouth structure that resembles a suction cup.

2. **Identifying the Division**: Cyclostomata belongs to the division Agnatha. Agnatha is a group that includes all jawless vertebrates, which is the defining characteristic of this division.

3. **Evaluating the Options**:
- **Option 1: Pisces**: This division includes jawed fish (Gnathostomata), so Cyclostomata does not belong here.
- **Option 2: Agnatha**: Since Cyclostomata is a group of jawless fishes, this is the correct division.
- **Option 3: Acraniata**: This group includes organisms without a cranium. Cyclostomata does have a cranium, so this option is incorrect.
- **Option 4: Tetrapods**: This division includes organisms with paired appendages, such as amphibians, reptiles, birds, and mammals. Cyclostomata does not fit into this category.

4. **Conclusion**: Based on the characteristics and classification of Cyclostomata, it is clear that they belong to the division Agnatha.

**Final Answer**: Cyclostomata belongs to the division Agnatha.

---