Animal producing natural pearls belong to

Options

A. Echinodermata
B. Cyclostomata
C. Mollusca
D. Fishes.

Answer

To determine which group of animals produces natural pearls, we can follow these steps:

### Step 1: Identify the Options
The options provided are:
- Echinodermata
- Cyclostomata
- Mollusca
- Fishes

### Step 2: Understand the Characteristics of Each Group
1. **Echinodermata**: This phylum includes marine animals like starfish and sea urchins. They do not produce pearls.
2. **Cyclostomata**: This class includes jawless fish like lampreys and hagfish. They are not known for pearl production.
3. **Mollusca**: This phylum includes a variety of animals, including snails, octopuses, and bivalves (like oysters and clams). Bivalves are known for producing pearls.
4. **Fishes**: While some fish may have shiny scales, they do not produce pearls.

### Step 3: Focus on Mollusca
Among the options, **Mollusca** stands out because:
- It includes the class **Pelecypoda** (also known as Bivalvia), which contains oysters and clams, the primary producers of natural pearls.
- Pearls are formed as a defense mechanism against irritants entering the shell, where the mollusk secretes layers of nacre (mother of pearl) around the irritant.

### Step 4: Conclusion
Based on the information above, the correct answer is that animals producing natural pearls belong to the phylum **Mollusca**.

### Final Answer
**Mollusca**

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