Lampreys are

Options

A. ectoparasites
B. free living
C. endoparasites
D. invertebrates

Answer

**Step-by-Step Solution:**

1. **Understanding Lampreys**: Begin by identifying what lampreys are. Lampreys are jawless fish that belong to the class Cyclostomata within the subphylum Vertebrata.

2. **Classifying Lampreys**: Recognize that lampreys fall under the class Cyclostomata, which is characterized by the absence of jaws. This class includes other species like hagfish.

3. **Identifying Their Lifestyle**: Determine the lifestyle of lampreys. They are known to be ectoparasites, meaning they attach to other fish and feed on their blood and bodily fluids.

4. **Analyzing the Options**: Review the options provided:
- Ectoparasites
- Free living
- Endoparasites
- Invertebrates

5. **Eliminating Incorrect Options**:
- **Free Living**: Since lampreys are ectoparasites, they do not live freely; they depend on host fish.
- **Endoparasites**: Lampreys attach to the outside of their hosts rather than living inside them, so they are not endoparasites.
- **Invertebrates**: Lampreys are vertebrates, not invertebrates, as they belong to the subphylum Vertebrata.

6. **Conclusion**: Based on the analysis, the correct answer is that lampreys are ectoparasites.

**Final Answer**: Lampreys are ectoparasites.

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