Animals showing metameric segmentation are

Options

A. Poriferans
B. Annelids
C. Tape-worms
D. Aschelminthes

Answer

To answer the question about animals showing metameric segmentation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Metameric Segmentation**:
- Metameric segmentation, also known as metamerism, refers to the phenomenon where an organism's body is divided into a linear series of segments or metameres. Each segment can contain similar organs and tissues.

2. **Identifying Characteristics**:
- In metamerically segmented animals, the organs and tissues are repeated at regular intervals. This means that each segment (or somite) is structurally similar to the others.

3. **Examples of Metamerically Segmented Animals**:
- The most notable examples of animals that exhibit metameric segmentation are:
- **Annelids**: This group includes earthworms and leeches, which are classic examples of metameric segmentation.
- **Arthropods**: This group includes insects, arachnids, and crustaceans, which also show segmentation but with more complex structures.

4. **Exclusion of Other Options**:
- **Poriferans** (sponges) do not exhibit metameric segmentation; they are more simple and lack true tissues.
- **Tapeworms** (a type of flatworm) do show segmentation, but it is not true metamerism as seen in annelids and arthropods; their segments (proglottids) are not repeated in the same way.
- **Aeschylmenthis** is not a commonly recognized group in the context of metameric segmentation.

5. **Conclusion**:
- Based on the above analysis, the correct answer to the question is **Annelids**.

### Final Answer:
Animals showing metameric segmentation are **Annelids**.

---