The given specimen has following features : (a)Aquatic, Cold-blooded animals (b) Skin covered with scales is two-chambered (d)Fins and muscular tail help them to swim in water. (i) Identify the specimen. (ii) Name the groups (class) to which it belongs. (iii) Give one adaptation w.r.t. its habitat.

Answer

### Step-by-Step Solution:

**Step 1: Identify the Specimen**
The specimen described is an aquatic, cold-blooded animal with skin covered in scales, a two-chambered heart, fins, and a muscular tail. Based on these characteristics, we can identify the specimen as **fish**.

**Step 2: Name the Groups (Class) to Which It Belongs**
Fishes are classified into three main groups (or classes):
1. **Agnatha**: Jawless fish (e.g., lampreys and hagfish).
2. **Chondrichthyes**: Cartilaginous fish (e.g., sharks and rays).
3. **Osteichthyes**: Bony fish (e.g., salmon, goldfish).

**Step 3: Give One Adaptation with Respect to Its Habitat**
One significant adaptation of fish to their aquatic habitat is their **spindle-shaped body**, which helps reduce water resistance while swimming. Additionally, many fish possess **air bladders**, which help them maintain buoyancy and prevent sinking in water.