Select the animal which exhibits retrogressive metamorphosis

Options

A. Bufo
B. Amphioxus
C. Limulus
D. Herdmania

Answer

To solve the question of which animal exhibits retrogressive metamorphosis, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Retrogressive Metamorphosis**:
- Retrogressive metamorphosis is a type of metamorphosis where the larval stage is more developed than the adult stage. In this process, the adult form is often simpler and more primitive compared to the larval form.

2. **Identify Characteristics of Retrogressive Metamorphosis**:
- In animals exhibiting retrogressive metamorphosis, the larval stage typically possesses features such as a tail and a notochord, which are lost or degenerate in the adult stage.

3. **Examine the Options Provided**:
- The question provides several animal options. We need to evaluate each one to see if they fit the criteria for retrogressive metamorphosis.

4. **Evaluate Each Option**:
- **Buffo (Toad)**: This belongs to the class Amphibia and exhibits typical amphibian metamorphosis, not retrogressive metamorphosis.
- **Amphioxus**: This is an invertebrate chordate, specifically a cephalochordate. It does not exhibit retrogressive metamorphosis.
- **Numilus**: This organism belongs to the phylum Mollusca (specifically, it is a type of cephalopod). It does not exhibit retrogressive metamorphosis.
- **Hardmania**: This organism belongs to the urochordates and is known to exhibit retrogressive metamorphosis, as the larval stage has a tail and notochord, which are lost in the adult form.

5. **Conclusion**:
- Based on the evaluation, the correct answer is **Hardmania**, as it is the only option that exhibits retrogressive metamorphosis.

### Final Answer:
The animal that exhibits retrogressive metamorphosis is **Hardmania**.

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