Which one of the following animals belongs to Cyclostomata?

Options

A. Channa
B. Loris
C. Dodo
D. Petromyzon

Answer

To determine which animal belongs to the class Cyclostomata, we will analyze the options provided:

1. **Understanding Cyclostomata**: Cyclostomata is a class of jawless fish that includes animals like lampreys and hagfish. They are characterized by their elongated bodies, circular mouths with no jaws, and several pairs of gill slits.

2. **Analyzing the Options**:
- **A. Pavo**: This is the scientific name for the peacock, which is a bird and belongs to the class Aves.
- **B. Loris**: This is a type of primate that belongs to the class Mammalia.
- **C. Dodo**: The dodo is an extinct bird, also belonging to the class Aves.
- **D. Petromycin**: This is a type of lamprey, which is a member of the class Cyclostomata.

3. **Conclusion**: The only animal from the options that belongs to the class Cyclostomata is **D. Petromycin**.

### Step-by-Step Solution:
1. Identify the characteristics of Cyclostomata.
2. Review the options provided.
3. Determine the classification of each option.
4. Identify which option belongs to Cyclostomata.
5. Conclude that the correct answer is D. Petromycin.