In fishes the exoskeleton is made of

Options

A. Cartilage
B. Bones
C. Hairs
D. Scales

Answer

**Step-by-Step Solution:**

1. **Understanding Exoskeleton**: An exoskeleton is an external skeleton that supports and protects an animal's body. In fishes, we need to identify what forms this exoskeleton.

2. **Evaluating Options**:
- **Option 1: Cartilage**: This is incorrect. Cartilage is a type of connective tissue that forms part of the endoskeleton in some fishes, not the exoskeleton.
- **Option 2: Bones**: This is also incorrect. While some fishes have a bony structure, bones are part of the endoskeleton, not the exoskeleton.
- **Option 3: Hairs**: This option is incorrect as well. Fishes do not have hairs; they are not a feature of their anatomy.
- **Option 4: Scales**: This is the correct answer. Scales are the dermal structures that cover the skin of fishes and constitute their exoskeleton.

3. **Conclusion**: The exoskeleton of fishes is made of scales, which are dermal scales present on the epidermis of the fish.

**Final Answer**: In fishes, the exoskeleton is made of scales.

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