Why no amphibian is marine in habitat ?

Explanation

### Step-by-Step Solution:

1. **Understanding Amphibians**: Amphibians are a class of animals that typically live both on land and in water. They include frogs, toads, salamanders, and newts.

2. **Skin Characteristics**: Amphibians have thin, moist skin that is permeable. This skin is essential for their respiration, as they can absorb oxygen directly through it in a process known as cutaneous respiration.

3. **Adaptation to Freshwater**: Amphibians are adapted to live in freshwater environments where the salinity (salt concentration) is low. Their skin allows for the absorption of water and oxygen, which is crucial for their survival.

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