Which one of the the following traits is not a characteristic feature of amphibians

Options

A. requirment of water for reproduction
B. amniotic eggs
C. thin skin without scales.
D. cutaneous respiration

Answer

### Step-by-Step Solution:

1. **Understanding Amphibians**:
- Amphibians are a class of animals that exhibit a dual life. They typically spend their larval stages in water and their adult stages on land. The term "amphibian" itself comes from the Greek words "amphi," meaning dual, and "bios," meaning life.

2. **Analyzing the Options**:
- The question asks for a trait that is **not** characteristic of amphibians. We will evaluate each option to identify which one does not apply to amphibians.

3. **Option 1: Requirement of Water for Reproduction**:
- Amphibians require water for reproduction. They typically have external fertilization, where the female lays eggs in water, and the male releases sperm nearby. Thus, this option is a characteristic feature of amphibians.

4. **Option 2: Amniotic Eggs**:
- Amniotic eggs are characterized by the presence of a protective membrane (amnion) and are typical of reptiles, birds, and mammals. Amphibians do not have amniotic eggs; instead, they lay eggs that are usually surrounded by a gelatinous substance in water. Therefore, this option is **not** a characteristic feature of amphibians.

5. **Option 3: Thin Skin Without Scales**:
- Amphibians have thin, moist skin that lacks scales. This is indeed a characteristic feature of amphibians, allowing for cutaneous respiration (gas exchange through the skin).

6. **Option 4: Cutaneous Respiration**:
- Amphibians can breathe through their skin, a process known as cutaneous respiration. Their moist skin facilitates this gas exchange, making it a characteristic feature of amphibians.

7. **Conclusion**:
- After evaluating all options, the trait that is **not** a characteristic feature of amphibians is **Option 2: Amniotic Eggs**.

### Final Answer:
**Amniotic Eggs** (Option 2) is not a characteristic feature of amphibians.

---