In which subphylum notochord is present only in larval tail?

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks us to identify the subphylum in which the notochord is present only in the larval tail.

2. **Identifying the Subphylum**: The subphylum that fits this description is Urochordata. Urochordates are a group of animals that are part of the protochordates.

3. **Characteristics of Urochordates**:
- In their larval stage, Urochordates possess a notochord, which is a flexible rod-like structure that provides support.
- This notochord is specifically located in the tail region of the larva.

4. **Adult Stage of Urochordates**:
- It is important to note that in the adult stage of Urochordates, the notochord is absent. This means that the notochord is only a feature of the larval form.

5. **Conclusion**: Therefore, the subphylum in which the notochord is present only in the larval tail is Urochordata.

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