Cartilaginous fishes are different from bony fishes in

Options

A. having accessor respiratory devices
B. males without claspers
C. not having a gas filled bladder
D. none of the above

Answer

To answer the question about how cartilaginous fishes differ from bony fishes, we will analyze each of the given options step by step.

### Step 1: Analyze Option A - Accessory Respiratory Devices
- **Explanation**: Cartilaginous fishes (like sharks and rays) and bony fishes both have gills for respiration. However, bony fishes have an operculum that covers their gills, while cartilaginous fishes do not have this structure. Therefore, the statement about having accessory respiratory devices is misleading.
- **Conclusion**: This statement is false.

### Step 2: Analyze Option B - Males Without Claspers
- **Explanation**: In cartilaginous fishes, males possess claspers, which are modified pelvic fins used for reproduction. This is a distinguishing feature of male cartilaginous fishes. Therefore, the statement that males are without claspers is incorrect.
- **Conclusion**: This statement is false.

### Step 3: Analyze Option C - Not Having Gas Bladder
- **Explanation**: Cartilaginous fishes do not have a swim bladder (often referred to as a gas bladder), which is present in bony fishes. The swim bladder helps bony fishes maintain buoyancy in water. Without it, cartilaginous fishes must swim continuously to avoid sinking, as they lack this buoyancy control mechanism.
- **Conclusion**: This statement is true.

### Step 4: Analyze Option D - None of the Above
- **Explanation**: Since we have established that Options A and B are false and Option C is true, this option cannot be correct.
- **Conclusion**: This statement is false.

### Final Answer
Based on the analysis, the correct answer to the question is **C: Not having gas bladder**.

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